REAR BICYCLE CHAINRING AND BICYCLE DRIVETRAIN

Abstract

Rear bicycle chainring assembly designed for attachment to a chainring support body of a rear bicycle hub assembly, the rear bicycle chainring assembly comprising: several bicycle chainrings, including: a first sprocket, featuring: a first opening with a first minimum diameter that is smaller than a minimum outer diameter of the sprocket support body of the rear bicycle hub assembly; and a second sprocket, having: a second opening having a second minimum diameter that is equal to or greater than the minimum outer diameter of the sprocket support body of the rear bicycle hub assembly; and at least ten internal splined teeth designed to engage with the sprocket support body of the rear bicycle hub assembly, wherein at least one of the at least ten internal sprocket teeth of the second sprocket is symmetrical in the circumferential direction with respect to a reference line extending from the axis of rotation to a circumferential center of a radially outermost end of the at least one of the at least ten internal sprocket teeth in a radial direction with respect to the axis of rotation. which have at least ten internal splined teeth, several internal splined drive surfaces, each comprising several internal splined drive surfaces: a radial outermost edge, a radial innermost edge, and a radial length defined from the radially outermost edge to the radially innermost edge, and a sum of the radial lengths of the multiple internal splined drive surfaces equal to or greater than 7 mm, and wherein at least one of the at least ten internal wedge teeth includes: an internal spline drive surface with a first internal spline surface angle defined between the internal spline drive surface and a first radial line extending from a rotational center axis of the rear bicycle chainring assembly to a radially outermost edge of the internal spline drive surface, and the first internal spline surface angle lies in the range of 0 degrees to 6 degrees.

Description

BACKGROUND OF THE INVENTION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority over US patent applications US 15 / 608,924 and US 15 / 608,915, filed on May 30, 2017; US patent application US 15 / 673,346, filed on August 9, 2017; US patent applications US 15 / 686,177 and US 15 / 686,179, filed on August 25, 2017; US patent application US 15 / 712,388 and US patent application US 15 / 712,407, filed on September 22, 2017; and US patent applications US 15 / 851,781 and US patent application 15 / 851,785, filed on December 22, 2017. The content of these applications will Hereinin by reference in its entirety. AREA OF INVENTION

[0002] The present invention relates to a rear bicycle chainring assembly and a bicycle drivetrain. BACKGROUND DISCUSSION

[0003] Cycling is becoming an increasingly popular form of leisure activity and a means of transportation. Furthermore, cycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for leisure, transportation, or competition, the bicycle industry is constantly improving the various components of the bicycle. One bicycle component that has undergone extensive redesign is the chainring assembly. US 2016 0 083 045 A1, for example, shows a chainring assembly and a chainring device in use, the chainring device comprising a driver, a shift sleeve, several chainrings of varying diameters, several connectors, and a fastener. The driver is connected to a rear wheel hub of a bicycle to transmit torque. One end of the shift sleeve is screwed into the driver.The sprockets, stacked axially from the largest to the smallest, are arranged in a direction from the driver to the shift sleeve. Each sprocket has circumferential teeth that can selectively engage with a chain. The ring-shaped connectors are arranged between each pair of sprockets. The fastening element is screwed into the other end of the shift sleeve to axially fix the shift sleeve. DE 10 2015 005 141 A1 shows a bicycle hub assembly comprising a hub shaft, a hub shell, and a sprocket support link. The sprocket support link comprises a tubular section and a first tooth. The tubular section includes an outer peripheral surface and a mounting section, which is provided only radially inside the outer peripheral surface. The first tooth is designed to be attached to the mounting section of the tubular section.The first tooth comprises a first surface and a second surface. The first surface is designed to face a mounting section of a bicycle chainring in one circumferential direction of the chainring support link. The second surface is opposite the first surface in the circumferential direction. The second surface is designed to face the mounting section of the bicycle chainring in the circumferential direction. SUMMARY OF THE INVENTION

[0004] According to a first aspect of the present invention, a rear bicycle sprocket assembly is configured for attachment to a sprocket support body of a rear bicycle hub assembly. The rear bicycle sprocket assembly comprises several bicycle sprockets. The multiple bicycle sprockets include a first sprocket and a second sprocket. The first sprocket has a first opening with a first minimum diameter that is smaller than a minimum outer diameter of the sprocket support body of the rear bicycle hub assembly. The second sprocket has a second opening and at least ten internal splines or internal teeth. The second opening has a second minimum diameter that is equal to or larger than the minimum outer diameter of the sprocket support body of the rear bicycle hub assembly. The at least ten internal teeth are configured to engage with the sprocket support body of the rear bicycle hub assembly.Furthermore, according to the first aspect, the rear bicycle chainring assembly is configured such that at least one of the at least ten internal sprocket teeth of the second chainring is circumferentially symmetrical with respect to a reference line extending from the axis of rotation to the circumcenter of a radially outermost end of at least one of the at least ten internal sprocket teeth in a radial direction with respect to the axis of rotation. Furthermore, according to the first aspect, the rear bicycle chainring assembly is configured such that the at least ten internal sprocket teeth comprise multiple internal splined drive surfaces. Each of the multiple internal splined drive surfaces comprises a radially outermost edge, a radially innermost edge, and a radial length defined from the radially outermost edge to the radially innermost edge. The sum of the radial lengths of the multiple internal splined drive surfaces is equal to or greater than 7 mm.Furthermore, according to the first aspect, the rear bicycle chainring assembly is designed such that at least one of the at least ten internal spline teeth has an internal spline or internal spline drive surface with a first internal spline or internal spline surface angle defined between the internal spline drive surface and a first radial line extending from a rotational center axis of the rear bicycle chainring assembly to a radially outermost edge of the internal spline drive surface. The first internal spline surface angle is in the range of 0 degrees to 6 degrees.

[0005] In the rear sprocket arrangement according to the first aspect, the first minimum diameter allows the first sprocket to have a smaller pitch circle diameter. This enables a wider gear range for the rear sprocket. Furthermore, the minimum of ten internal splines on the second sprocket reduces the torque applied to each of the at least ten internal splines compared to a sprocket with nine or fewer internal splines. This improves the durability of the second sprocket and / or provides more freedom in choosing a material for the second sprocket without reducing its durability. In the rear sprocket arrangement according to the first aspect, it is possible to improve the productivity of the rear sprocket due to the symmetrical shape of the internal splines.In the rear bicycle chainring arrangement, according to the first aspect, it is possible to increase the radial lengths of the multiple internal splined drive surfaces. This improves the strength of the second chainring. In the rear bicycle chainring arrangement, according to the first aspect, it is also possible to improve the strength of the internal splined drive surface.

[0006] According to a second aspect of the present invention, the rear bicycle chainring assembly according to the first aspect further comprises a locking element. The locking element comprises a tubular body, an externally threaded section, and a radial projection. The tubular body extends through the first opening of the first chainring in a state in which the rear bicycle chainring assembly is attached to the rear bicycle hub assembly. The tubular body comprises a first axial end and a second axial end. The second axial end is arranged relative to the first axial end in an axial direction with respect to a rotational center axis of the rear bicycle chainring assembly. In the state in which the rear bicycle chainring assembly is attached to the rear bicycle hub assembly, the first axial end is arranged closer to an axial center plane of the rear bicycle hub assembly than the second axial end.The external threaded section is provided at the first axial end to engage with an internal threaded section of the sprocket support body of the rear bicycle hub assembly when the rear bicycle sprocket assembly is attached to the rear bicycle hub assembly. The radial projection extends radially outward from the second axial end with respect to the axis of rotation to restrict axial movement of the first sprocket relative to the sprocket support body of the rear bicycle hub assembly when the rear bicycle sprocket assembly is attached to the rear bicycle hub assembly.

[0007] In the second aspect of the rear bicycle chainring arrangement, it is possible to attach a smaller chainring to the rear bicycle hub. This allows for a wider gear range of the rear bicycle chainring arrangement.

[0008] According to a third aspect of the present invention, the rear bicycle chainring assembly according to the second aspect is configured such that the first chainring has a first inwardly facing side and a first outwardly facing side, which is axially opposite the first inwardly facing side. The radial projection is configured such that it bears against the first chainring at the first outwardly facing side.

[0009] In the third aspect of the rear bicycle chainring arrangement, it is possible to attach a smaller chainring to the rear bicycle hub. This allows for a wider gear range of the rear bicycle chainring arrangement.

[0010] According to a fourth aspect of the present invention, the rear bicycle chainring assembly is arranged according to one of the first to third aspects such that the second chainring is arranged in an axial direction with respect to a rotational center axis of the rear bicycle chainring assembly without another chainring being located adjacent to the first chainring between the first chainring and the second chainring.

[0011] In the rear bicycle chainring arrangement according to the fourth aspect, it is possible to attach a smaller chainring to the rear bicycle hub. This allows for a wider gear range of the rear bicycle chainring arrangement.

[0012] According to a fifth aspect of the present invention, the rear bicycle chainring assembly is configured according to aspects one through four such that the first chainring has a first inwardly facing side and a first outwardly facing side located in an axial direction relative to a rotational axis of the rear bicycle chainring assembly opposite the first inwardly facing side. The first chainring has a first torque transmission structure provided on the first inwardly facing side to transmit a pedal actuation torque directly or indirectly to the chainring support body.

[0013] In the rear bicycle chainring arrangement according to the fifth aspect, it is possible to attach a smaller chainring to the rear bicycle hub. This allows for a wider gear range of the rear bicycle chainring arrangement.

[0014] According to a sixth aspect of the present invention, the rear bicycle chainring assembly according to the fifth aspect is arranged such that the first torque transmission structure comprises at least ten first torque transmission teeth.

[0015] In the rear bicycle chainring arrangement according to the sixth aspect, the first chainring's minimum of ten torque-transmitting teeth reduces the torque applied to each of those teeth compared to a chainring with nine or fewer internal splines. This improves the first chainring's durability and / or provides more freedom in choosing a material for the first chainring without reducing its durability.

[0016] According to a seventh aspect of the present invention, the rear bicycle chainring arrangement according to the sixth aspect is configured such that the total number of the at least ten first torque transmission teeth is equal to or greater than 20.

[0017] In the rear bicycle chainring arrangement according to the seventh aspect, it is possible to improve the durability of the first chainring.

[0018] According to an eighth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to seventh aspects such that the total number of the at least ten internal sprocket teeth of the second chainring is equal to or greater than 20.

[0019] In the rear bicycle chainring arrangement according to the eighth aspect, it is possible to improve the durability of the second chainring.

[0020] According to a ninth aspect of the present invention, the rear bicycle chainring arrangement according to the eighth aspect is configured such that the total number of the at least ten internal sprocket teeth of the second chainring is equal to or greater than 28.

[0021] In the rear bicycle chainring arrangement according to the ninth aspect, it is possible to improve the durability of the second chainring.

[0022] According to a tenth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to ninth aspects such that the at least ten internal splined teeth of the second chainring have a first inner helix angle and a second inner helix angle that differs from the first inner helix angle.

[0023] According to the tenth aspect of the rear bicycle chainring assembly, it is possible to easily attach the rear bicycle chainring assembly to the rear bicycle hub assembly in a correct circumferential position.

[0024] According to an eleventh aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to tenth aspects such that at least one of the at least ten internal splined teeth of the second chainring has a first spline or splined tooth shape that differs from a second spline or splined tooth shape of another of the at least ten internal splined teeth.

[0025] According to the eleventh aspect, with the rear bicycle chainring assembly, it is possible to easily attach the rear bicycle chainring assembly to the rear bicycle hub assembly in a correct circumferential position.

[0026] According to a twelfth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to eleventh aspects such that at least one of the at least ten internal sprocket teeth of the second chainring has a first spline or spline tooth size that differs from a second spline or spline tooth size of another of the at least ten internal sprocket teeth.

[0027] According to the twelfth aspect, the rear bicycle chainring assembly can be easily attached to the rear bicycle hub assembly in a correct circumferential position.

[0028] According to a thirteenth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to twelfth aspects such that the total number of teeth of the first chainring is equal to or less than 10.

[0029] With the rear chainring arrangement according to the thirteenth aspect, it is possible to attach a smaller chainring to the rear hub. This allows for a wider gear range of the rear chainring arrangement.

[0030] According to a fourteenth aspect of the present invention, the rear bicycle chainring arrangement is arranged according to one of the first to thirteenth aspects such that the first chainring is the smallest chainring in the rear bicycle chainring arrangement.

[0031] With the rear chainring arrangement of the fourteenth aspect, it is possible to attach a smaller chainring to the rear hub. This allows for a wider gear range of the rear chainring arrangement.

[0032] According to a fifteenth aspect of the present invention, the rear bicycle chainring assembly, according to aspects one through fourteen, further comprises a chainring support element comprising at least ten internal splined teeth configured to engage with the chainring support body of the rear bicycle hub assembly. The multiple bicycle chainrings include an additional chainring configured to be attached to the chainring support element.

[0033] In the rear bicycle chainring arrangement according to the fifteenth aspect, it is possible to save weight in the rear bicycle chainring arrangement.

[0034] According to a sixteenth aspect of the present invention, the rear bicycle chainring arrangement according to the fifteenth aspect is configured such that the total number of teeth of the additional chainring is equal to or greater than 46.

[0035] In the rear bicycle chainring arrangement according to the sixteenth aspect, the additional chainring allows for a wider gear range of the rear bicycle chainring arrangement.

[0036] According to a seventeenth aspect of the present invention, the rear bicycle chainring arrangement according to the fifteenth aspect is configured such that the total number of teeth of the additional chainring is equal to or greater than 50.

[0037] In the rear bicycle chainring arrangement according to the seventeenth aspect, the additional chainring allows a wider gear range of the rear bicycle chainring arrangement.

[0038] According to an eighteenth aspect of the present invention, the rear bicycle chainring assembly is configured, according to aspects one through seventeen, such that the multiple bicycle chainrings comprise multiple second chainrings, which are provided as the second chainring. Each of the multiple second chainrings comprises at least ten internal sprocket teeth configured to engage with the chainring support body of the rear bicycle hub assembly.

[0039] In the rear bicycle chainring arrangement according to the eighteenth aspect, it is possible to improve the durability of the multiple second chainrings.

[0040] According to a nineteenth aspect of the present invention, the rear bicycle chainring assembly according to the eighteenth aspect further comprises a chainring support element having at least ten internal splined teeth designed to engage with the chainring support body of the rear bicycle hub assembly. The multiple bicycle chainrings include an additional chainring configured to be attached to the chainring support element.

[0041] In the rear bicycle chainring arrangement according to the nineteenth aspect, it is possible to save weight in the rear bicycle chainring arrangement.

[0042] According to a twentieth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to nineteenth aspects such that the total number of the multiple bicycle chainrings is equal to or greater than 10.

[0043] With the rear bicycle chainring arrangement according to the twentieth aspect, it is possible to increase one speed level of the rear bicycle chainring arrangement.

[0044] According to a twenty-first aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to twentieth aspects such that the total number of the multiple bicycle chainrings is equal to or greater than 11.

[0045] With the rear bicycle chainring arrangement according to the twenty-first aspect, it is possible to further increase one speed level of the rear bicycle chainring arrangement.

[0046] According to a twenty-second aspect of the present invention, the rear bicycle chainring arrangement is configured according to aspects one through the twenty-first such that the total number of bicycle chainrings is equal to or greater than 12.

[0047] With the rear bicycle chainring arrangement according to the twenty-second aspect, it is possible to further increase one speed level of the rear bicycle chainring arrangement.

[0048] According to a twenty-third aspect of the present invention, the rear bicycle chainring assembly is configured according to aspects one through twenty-two such that the multiple bicycle chainrings include an additional chainring with a largest tooth tip diameter. The at least ten internal spline teeth of the second chainring comprise an internal spline minor diameter. The ratio of the internal spline minor diameter to the largest tooth tip diameter is in the range of 0.15 to 0.18.

[0049] In the rear bicycle chainring arrangement according to the twenty-third aspect, it is possible to improve the durability of the second chainring, and a wider gear range of the rear bicycle chainring arrangement is made possible.

[0050] According to a twenty-fourth aspect of the present invention, the rear bicycle chainring assembly, according to aspects one through twenty-three, further comprises an additional chainring. The additional chainring comprises at least a first shifting drive area to facilitate a first shifting operation in which a bicycle chain shifts from the additional chainring to an adjacent smaller chainring, and at least a second shifting drive area to facilitate a second shifting operation in which the bicycle chain shifts from the adjacent smaller chainring to the additional chainring.

[0051] With the rear bicycle chainring arrangement according to the twenty-fourth aspect, it is possible to perform the first shifting operation and the second shifting operation smoothly.

[0052] According to a twenty-fifth aspect of the present invention, the rear bicycle chainring assembly according to the second or third aspect is arranged such that the tubular body has a first outer diameter that is equal to or less than 27 mm.

[0053] In the rear bicycle chainring arrangement according to the twenty-fifth aspect, it is possible to hold the rear bicycle chainring arrangement with respect to the rear bicycle hub arrangement using the locking element and to allow a wider gear range of the rear bicycle chainring arrangement.

[0054] According to a twenty-sixth aspect of the present invention, the rear bicycle chainring assembly according to the twenty-fifth aspect is arranged such that the first outer diameter is equal to or greater than 26 mm.

[0055] In the rear bicycle chainring assembly according to the twenty-sixth aspect, it is possible to maintain or improve the strength of the locking element and to allow a wider gear range of the rear bicycle chainring assembly.

[0056] According to a twenty-seventh aspect of the present invention, the rear bicycle chainring assembly according to the second, third, twenty-fifth or twenty-sixth aspect is arranged such that the radial projection has a second outer diameter equal to or less than 32 mm.

[0057] In the rear bicycle chainring arrangement according to the twenty-seventh aspect, it is possible to hold the rear bicycle chainring arrangement with respect to the rear bicycle hub arrangement using the locking element and to allow a wider gear range of the rear bicycle chainring arrangement.

[0058] According to a twenty-eighth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the twenty-seventh aspect such that the second outer diameter is equal to or greater than 30 mm.

[0059] In the rear bicycle chainring assembly according to the twenty-eighth aspect, it is possible to maintain or improve the strength of the locking element by allowing a wider gear range of the rear bicycle chainring assembly.

[0060] According to a twenty-ninth aspect of the present invention, the rear bicycle chainring assembly is arranged according to aspects two, three and twenty-fifth to twenty-eighth such that the locking element has a tool engagement section.

[0061] In the rear bicycle chainring arrangement according to the twenty-ninth aspect, it is possible to easily attach the locking element using the tool engagement section.

[0062] According to a thirtieth aspect of the present invention, the rear bicycle chainring assembly is configured according to aspects one through twenty-ninth such that the multiple bicycle chainrings comprise multiple first chainrings, which are designated as the first chainring, and multiple second chainrings, which are designated as the second chainring. The multiple first chainrings each have the first opening. The multiple second chainrings each have the second opening and the at least ten internal splined teeth configured to engage with the chainring support body of the rear bicycle hub assembly.

[0063] In the rear bicycle chainring arrangement according to the thirtieth aspect, the multiple first chainrings and the multiple second chainrings allow a wider gear range of the rear bicycle chainring arrangement.

[0064] According to a thirty-first aspect of the present invention, the rear bicycle chainring assembly according to the fifteenth aspect is arranged such that the additional chainring is attached to the chainring support element by means of adhesive.

[0065] In the rear bicycle chainring assembly according to aspect thirty-first, it is possible to save weight in the rear bicycle chainring assembly because no metallic fastening element is used.

[0066] According to a thirty-second aspect of the present invention, the rear bicycle chainring assembly according to the fifteenth or thirty-first aspect is arranged such that the chainring support element is made of a non-metallic material comprising a resin material.

[0067] In the rear bicycle chainring arrangement according to the thirty-second aspect, it is possible to further reduce the weight of the rear bicycle chainring arrangement.

[0068] According to a thirty-third aspect of the present invention, the rear bicycle chainring assembly is configured according to aspects one through thirty-second such that at least two of the at least ten internal sprocket teeth of the second chainring are arranged circumferentially at a first inner helix angle with respect to a rotational center axis of the rear bicycle chainring assembly. The first inner helix angle ranges from 5 degrees to 36 degrees.

[0069] In the rear bicycle chainring arrangement according to aspect thirty-third, it is possible to improve the durability of the second chainring.

[0070] According to a thirty-fourth aspect of the present invention, the rear bicycle chainring assembly according to the thirty-third aspect is arranged such that the first inner inclination angle is in the range of 10 degrees to 20 degrees.

[0071] In the rear bicycle chainring arrangement according to aspect thirty-four, it is possible to further improve the durability of the second chainring.

[0072] According to a thirty-fifth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the thirty-fourth aspect such that the first inner helix angle is equal to or less than 15 degrees.

[0073] In the rear bicycle chainring arrangement according to the thirty-fifth aspect, it is possible to further improve the durability of the second chainring.

[0074] According to a thirty-sixth aspect of the present invention, the rear bicycle chainring assembly is arranged, according to aspects thirty-three to thirty-five, such that at least two other internal sprocket teeth of the at least ten internal sprocket teeth of the second chainring are arranged circumferentially at a second internal helix angle with respect to the axis of rotation. The second internal helix angle differs from the first internal helix angle.

[0075] According to aspect thirty-six, the rear bicycle chainring assembly can be easily attached to the rear bicycle hub assembly in a correct circumferential position.

[0076] According to a thirty-seventh aspect of the present invention, the rear bicycle chainring arrangement is configured according to aspects one through the thirty-sixth such that the at least ten internal splined teeth of the second chainring have an internal splined main diameter equal to or less than 34 mm.

[0077] In the rear bicycle chainring arrangement according to the thirty-seventh aspect, it is possible to improve the durability of the second chainring, allowing a wider gear range of the rear bicycle chainring arrangement.

[0078] According to a thirty-eighth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the thirty-seventh aspect such that the inner sprocket sprocket main diameter of the second chainring is equal to or less than 33 mm.

[0079] In the rear bicycle chainring arrangement according to aspect thirty-eight, it is possible to improve the durability of the second chainring by allowing a wider gear range of the rear bicycle chainring arrangement.

[0080] According to a thirty-ninth aspect of the present invention, the rear bicycle chainring arrangement is configured according to the thirty-seventh or thirty-eighth aspect such that the internal sprocket main diameter of the second chainring is equal to or greater than 29 mm.

[0081] In the rear bicycle chainring arrangement according to aspect thirty-ninth, it is possible to improve the durability of the second chainring.

[0082] According to a fortieth aspect of the present invention, the rear bicycle chainring arrangement is configured according to one of the first to thirty-ninth aspects such that the at least ten internal spline teeth of the second chainring comprise an internal spline or internal spline toothing secondary diameter equal to or less than 32 mm.

[0083] In the rear sprocket arrangement of the fortieth aspect, the internal spline major diameter can increase the radial length of a drive surface of at least one internal spline tooth. This improves the strength of the second sprocket.

[0084] According to a forty-first aspect of the present invention, the rear bicycle chainring assembly is arranged according to the fortieth aspect such that the internal splined secondary diameter is equal to or less than 31 mm.

[0085] In the rear bicycle sprocket arrangement according to aspect forty-first, the secondary diameter of the internal spline can further increase the radial length of a drive surface of at least one internal spline tooth. This improves the strength of the second sprocket.

[0086] According to a forty-second aspect of the present invention, the rear bicycle chainring assembly is arranged according to the fortieth or forty-first aspect such that the internal splined secondary diameter is equal to or greater than 28 mm.

[0087] In the rear bicycle chainring arrangement according to aspect forty-second, it is possible to obtain the necessary strength of the chainring support body.

[0088] According to a forty-fourth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the forty-third aspect such that the sum of the radial lengths is equal to or greater than 10 mm.

[0089] In the rear bicycle sprocket arrangement according to aspect forty-four, it is possible to further increase the radial lengths of the multiple internal splined drive surfaces. This improves the strength of the second sprocket.

[0090] According to a forty-fifth aspect of the present invention, the rear bicycle chainring assembly according to the forty-third aspect is arranged such that the sum of the radial lengths is equal to or greater than 15 mm.

[0091] In the rear bicycle sprocket arrangement according to aspect forty-fifth, it is possible to further increase the radial lengths of the multiple internal splined drive surfaces. This improves the strength of the second sprocket.

[0092] According to a forty-sixth aspect of the present invention, the rear bicycle chainring assembly is arranged according to aspects forty-three to forty-five such that the sum of the radial lengths is equal to or less than 36 mm.

[0093] In the rear bicycle chainring arrangement according to the forty-sixth aspect, it is possible to further improve the productivity of the rear bicycle chainring arrangement.

[0094] According to a forty-eighth aspect of the present invention, the rear bicycle sprocket assembly is configured such that at least one of the at least ten internal splines has an internal spline drive surface with a second internal spline surface angle defined between the internal spline or internal spline non-drive surface and a second radial line extending from the rotational center axis of the rear bicycle sprocket assembly to a radially outermost edge of the internal spline non-drive surface. The second internal spline surface angle is between 0 degrees and 6 degrees.

[0095] In the rear bicycle chainring arrangement according to the forty-eighth aspect, it is possible to improve the productivity of the rear bicycle chainring arrangement due to a symmetrical shape of the inner splined tooth.

[0096] According to a fiftieth aspect of the present invention, a bicycle drivetrain comprises the rear bicycle sprocket assembly according to aspects one through forty-ninth and a rear bicycle hub assembly. The rear bicycle hub assembly comprises a hub axle having an axle through-bore with a minimum inner diameter of 13 mm or greater, a hub body rotatably mounted on the hub axle about a central axis of rotation of the rear bicycle hub assembly, and a sprocket support body rotatably mounted on the hub axle about the central axis of rotation.

[0097] With the bicycle drivetrain according to the fiftieth aspect, it is possible to improve the strength of the bicycle drivetrain around a rear wheel and to allow a wider gear range of the rear bicycle chainring arrangement.

[0098] According to a fifty-first aspect of the present invention, the bicycle drive train is arranged such that the minimum inner diameter of the axle passage bore is equal to or greater than 14 mm.

[0099] With the bicycle drivetrain according to the fifty-first aspect, it is possible to further improve the strength of the bicycle drivetrain around a rear wheel.

[0100] According to a fifty-second aspect of the present invention, the bicycle drive train is arranged according to the fiftieth or fifty-first aspect such that the minimum inner diameter of the axle passage bore is equal to or less than 21 mm.

[0101] With the bicycle drivetrain according to the fifty-second aspect, it is possible to improve the degree of freedom in the design of the rear bicycle hub arrangement.

[0102] According to a fifty-third aspect of the present invention, the rear bicycle chainring arrangement according to the sixth aspect is such that a total number of the at least ten first torque transmission teeth is in the range of 22 to 24.

[0103] In the rear bicycle sprocket arrangement according to the fifty-third aspect, the total number of at least ten first torque transmission teeth improves the durability of the second sprocket and improves the productivity of the rear bicycle sprocket arrangement.

[0104] According to a fifty-fourth aspect of the present invention, the rear bicycle chainring arrangement according to the first aspect is configured such that a total number of the at least ten internal sprocket teeth of the second chainring is in the range of 22 to 24.

[0105] In the rear bicycle sprocket arrangement according to the fifty-fourth aspect, the total number of at least ten first torque transmission teeth improves the durability of the second sprocket and improves the productivity of the rear bicycle sprocket arrangement.

[0106] According to a fifty-fifth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the thirty-third aspect such that the first inner inclination angle is in the range of 13 degrees to 17 degrees.

[0107] In the rear bicycle chainring arrangement according to the fifty-fifth aspect, the first inner helix angle improves the durability of the second chainring, thus improving the productivity of the rear bicycle chainring arrangement.

[0108] According to a fifty-sixth aspect of the present invention, the rear bicycle chainring assembly is arranged according to the thirty-sixth aspect such that the second inner inclination angle is in the range of 28 degrees to 32 degrees.

[0109] In the case of the rear bicycle chainring assembly according to the fifty-sixth aspect, it is possible to easily attach the rear bicycle chainring assembly to the rear bicycle hub assembly in a correct circumferential position.

[0110] According to a fifty-seventh aspect of the present invention, the rear bicycle chainring assembly is arranged according to the thirty-sixth aspect such that the first inner helix angle is half of the second inner helix angle.

[0111] In the case of the rear bicycle chainring assembly according to the fifty-seventh aspect, it is possible to easily attach the rear bicycle chainring assembly to the rear bicycle hub assembly in a correct circumferential position.

[0112] According to a fifty-eighth aspect of the present invention, the rear bicycle chainring assembly according to the forty-third aspect is arranged such that the sum of the radial lengths of the multiple internal splined drive surfaces is in the range of 11 mm to 14 mm.

[0113] In the rear bicycle sprocket assembly according to aspect fifty-eight, the main diameter of the internal sprocket teeth can increase the radial length of a drive surface of at least one internal sprocket tooth. This improves the strength of the second sprocket in a way that enhances the productivity of the rear bicycle sprocket assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] A more complete appreciation of the invention and many of its associated advantages will be easily obtained when they are better understood with reference to the following detailed description, when considered in conjunction with the accompanying drawings. Fig. Figure 1 is a schematic representation of a bicycle drive train according to one embodiment. Fig. 2 is a perspective exploded view of the bicycle drivetrain, which is in Fig. 1 is shown. Fig. Figure 3 is a cross-sectional view of the bicycle drivetrain along line III-III of Fig. 2. Fig. 4 is a perspective view of a rear bicycle hub assembly of the in Fig. 2 illustrated bicycle drive train with a locking element of a rear bicycle chainring assembly. Fig. 5 is a side elevation view of the rear bicycle chainring assembly of the in Fig. 1. Bicycle drivetrain shown. Fig. 6 is an enlarged cross-sectional view of the in Fig. 4 bicycle drivetrains shown. Fig. 7 is a side elevation view of a sprocket of the in Fig. 5 rear wheel arrangement shown. Fig. 8 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 9 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 10 is a side elevation view of a first sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 11 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 12 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 13 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 14 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 15 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 16 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 17 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 18 is a side elevation view of a sprocket of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. Figure 19 is a perspective exploded view of the in Fig. 5 rear bicycle chainring arrangement shown. Fig. 20 is a perspective view of a sprocket support body of the in Fig. 4 rear bicycle hub arrangement shown. Fig. Figure 21 is another perspective view of the sprocket support body of the in Fig. 4 rear bicycle hub arrangement shown. Fig. 22 is a rear view of the sprocket support body of the in Fig. 4 rear bicycle hub arrangement shown. Fig. 23 is a side elevation view of the sprocket support body of the in the Fig. 4 rear bicycle hub arrangement shown. Fig. Figure 24 is a side elevation view of the sprocket support body of the rear bicycle hub assembly according to a modification. Fig. 25 is an enlarged cross-sectional view of the in Fig. 23 depicted bicycle support body. Fig. 26 is a cross-sectional view of the in Fig. 23 depicted bicycle support body. Fig. 27 is a perspective view of the in Fig. 4 rear bicycle hub arrangement shown. Fig. 28 is a side elevation view of the in the Fig. 4 rear bicycle hub arrangement shown. Fig. 29 is a rear view of the one in the Fig. 4 rear bicycle hub arrangement shown. Fig. Figure 30 is a perspective exploded view of a sprocket support body and several spacers of the in Fig. 4 rear bicycle hub arrangement shown. Fig. Figure 31 is a partially enlarged cross-sectional view of the [unclear text]. Fig. 4 bicycle drivetrains shown. Fig. 32 is another side elevation view of the in Fig. 8 shown chain wheel. Fig. 33 is a side elevation view of the in Fig. 9 shown chain wheel. Fig. 34 is a side elevation view of the in Fig. 9 shown sprocket according to a modification. Fig. Figure 35 is an enlarged cross-sectional view of the [unclear text]. Fig. 29 shown chain wheel. Fig. 36 is another cross-sectional view of the in Fig. 29 shown chain wheel. Fig. 37 is another cross-sectional view of the in Fig. 2 bicycle drivetrains shown. Fig. 38 is a perspective exploded view of the [unclear] in the Fig. 7 and Fig. 8 sprockets shown. Fig. 39 is another perspective exploded view of the [unclear] in the Fig. 7 and Fig. 8 sprockets shown. Fig. Figure 40 is a perspective exploded view of part of the in Fig. 4 rear bicycle hub arrangement shown. Fig. Figure 41 is a perspective exploded view of part of the in Fig. 40 rear bicycle hub arrangement shown. Fig. Figure 42 is a perspective exploded view of part of the in Fig. 40 rear bicycle hub arrangement shown. Fig. Figure 43 is a perspective exploded view of part of the in Fig. 40 rear bicycle hub arrangement shown. Fig. 44 is a partial cross-sectional view of the in Fig. 40 rear bicycle hub arrangement shown. Fig. Figure 45 is a cross-sectional view of the rear bicycle hub arrangement along the XLV-XLV line. Fig. 44. Fig. Figure 46 is a perspective view of a spacer in Fig. 40 rear bicycle hub arrangement shown. Fig. Figure 47 is another perspective view of a spacer that is in Fig. 40 rear bicycle hub arrangement shown. Fig. Figure 48 is a schematic diagram illustrating the action of a first pawl element and a sprocket support body of the in Fig. Figure 40 shows the rear bicycle hub arrangement (pedal operation). Fig. Figure 49 is a schematic diagram illustrating the action of a first pawl element and a sprocket support body of the in Fig. 40 shows the rear bicycle hub arrangement (rolling out). Fig. Figure 50 is an enlarged cross-sectional view of the sprocket support body according to a modification. Fig. Figure 51 is an enlarged cross-sectional view of the sprocket according to a modification. Fig. Figure 52 is a side elevation view of a sprocket support body of a rear bicycle hub assembly according to a modification. Fig. 53 is an enlarged cross-sectional view of a Fig. 52 shown sprocket support body. Fig. Figure 54 is a perspective exploded view of sprockets of a rear bicycle sprocket assembly according to a modification. Fig. Figure 55 is another perspective exploded view of the sprockets of the rear bicycle sprocket assembly according to the modification. Fig. Figure 56 is a side elevation view of a sprocket of the rear bicycle sprocket arrangement according to the modification. Fig. Figure 57 is a side elevation view of a sprocket of the rear bicycle sprocket arrangement according to the modification. Fig. Figure 58 is a side elevation view of a sprocket of the rear bicycle sprocket arrangement according to the modification. Fig. 59 is a side elevation view of the in Fig. 57 shown chain wheel. Fig. Figure 60 is an enlarged cross-sectional view of the [unclear text]. Fig. 57 shown chain wheel. Fig. Figure 61 is a partial side elevation view of a sprocket support element of the rear bicycle sprocket assembly according to the modification. Fig. Figure 62 is a cross-sectional view of a bicycle drivetrain according to a modification. DESCRIPTION OF THE EXECUTION FORMS

[0115] The embodiment(s) will now be described with reference to the accompanying drawings, in which the same reference numerals denote corresponding or identical elements in the different drawings.

[0116] Initially referring to Fig. 1 comprises a bicycle drivetrain 10 according to one embodiment, a rear bicycle hub assembly 12, and a rear bicycle chainring assembly 14. The rear bicycle hub assembly 12 is attached to a bicycle frame BF. The rear bicycle chainring assembly 14 is attached to the rear bicycle hub assembly 12. A bicycle brake rotor 16 is attached to the rear bicycle hub assembly 12.

[0117] The bicycle drivetrain 10 further comprises a crank assembly 18 and a bicycle chain 20. The crank assembly 18 comprises a crankshaft 22, a right crank arm 24, a left crank arm 26, and a front sprocket 27. The right crank arm 24 and the left crank arm 26 are attached to the crank axle 22. The front sprocket 27 is attached to at least one of the crank axle 22 and the right crank arm 24. The bicycle chain 20 engages with the front sprocket 27 and the rear sprocket assembly 14 to transmit a pedaling force from the front sprocket 27 to the rear sprocket assembly 14. The crank assembly 18 comprises the front sprocket 27 as a single sprocket in the illustrated embodiment. However, the crank assembly 18 can comprise multiple front sprockets. The rear sprocket assembly 14 is a rear sprocket assembly.However, the structures of the rear bicycle chainring arrangement 14 can also be applied to the front chainring.

[0118] In the present application, the following directional terms, "front," "rear," "forward," "backward," "left," "right," "across," "upward," and "downward," as well as other similar directional designations, refer to those directions determined based on a user (e.g., a rider) seated on a saddle (not shown) of a bicycle facing a handlebar (not shown). Accordingly, these terms, as used to describe the bicycle drivetrain 10, the rear bicycle hub assembly 12, or the rear bicycle chainring assembly 14, should be interpreted in relation to the bicycle equipped with the bicycle drivetrain 10, the rear bicycle hub assembly 12, or the rear bicycle chainring assembly 14, as used in an upright riding position on a horizontal surface.

[0119] As in Fig. As shown in Figure 2, the rear bicycle hub assembly 12 and the rear bicycle chainring assembly 14 comprise a pivot axis A1. The rear bicycle chainring assembly 14 is defined by the rear bicycle hub assembly 12 with respect to the bicycle frame BF ( Fig. 1) Rotatably mounted about the axis of rotation A1. The rear bicycle chainring assembly 14 is configured to engage with the bicycle chain 20 in order to transmit a drive torque F1 between the bicycle chain 20 and the rear bicycle chainring assembly 14 during pedaling. The rear bicycle chainring assembly 14 rotates about the axis of rotation A1 in a drive direction D11 during pedaling. The drive direction D11 is defined along a circumferential direction D1 of the rear bicycle hub assembly 12 or the rear bicycle chainring assembly 14. An opposite direction of rotation D12 is the opposite direction to the drive direction D11 and is defined along the circumferential direction D1.

[0120] As in Fig. As shown in Figure 2, the rear bicycle hub assembly 12 comprises a sprocket support body 28. The rear bicycle sprocket assembly 14 is designed to be attached to the sprocket support body 28 of the rear bicycle hub assembly 12. The rear bicycle sprocket assembly 14 is attached to the sprocket support body 28 to transmit the drive torque F1 between the sprocket support body 28 and the rear bicycle sprocket assembly 14. The rear bicycle hub assembly 12 has a hub axle 30. The sprocket support body 28 is rotatably mounted on the hub axle 30 about the axis of rotation A1. The rear bicycle sprocket assembly 14 further comprises a locking element 32. The locking element 32 is attached to the sprocket support body 28 to hold the rear bicycle sprocket assembly 14 in an axial direction D2 with respect to the axis of rotation A1.

[0121] As in Fig. As shown in Figure 3, the rear bicycle hub assembly 12 is attached to the bicycle frame BF by a wheel mounting structure WS. The hub axle 30 includes an axle through-bore 30A. A mounting rod WS1 of the wheel mounting structure WS extends through the axle through-bore 30A of the hub axle 30. The hub axle 30 includes a first axle end 30B and a second axle end 30C. The hub axle 30 extends between the first axle end 30B and the second axle end 30C along the pivot axis A1. The first axle end 30B is provided in a first recess BF11 of a first frame BF1 of the bicycle frame BF. The second axle end 30C is provided in a second recess BF21 of a second frame BF2 of the bicycle frame BF. The hub axle 30 is held between the first frame BF1 and the second frame BF2 by the wheel mounting structure WS. The wheel mounting structure WS comprises a structure that is well-known in the field of bicycles.Therefore, for the sake of brevity, it will not be described in detail here.

[0122] In this embodiment, the through-hole 30A has a minimum inner diameter BD1 equal to or greater than 13 mm. The minimum inner diameter BD1 of the through-hole 30A is preferably equal to or greater than 14 mm. The minimum inner diameter BD1 of the through-hole 30A is preferably equal to or less than 21 mm. In this embodiment, the minimum inner diameter BD1 of the through-hole 30A is 15 mm. However, the minimum inner diameter BD1 is not limited to this embodiment and the aforementioned ranges.

[0123] The hub axle 30 comprises a maximum outer diameter BD2 that is equal to or greater than 17 mm. The maximum outer diameter BD2 of the hub axle 30 is preferably equal to or greater than 20 mm. The maximum outer diameter BD2 of the hub axle 30 is preferably equal to or less than 23 mm. In this embodiment, the maximum outer diameter BD2 of the hub axle 30 is 21 mm. However, the maximum outer diameter BD2 of the hub axle 30 is not limited to this embodiment and the aforementioned ranges. The hub axle 30 comprises a minimum outer diameter BD3 that is equal to or greater than 15 mm. The minimum outer diameter BD3 is preferably equal to or greater than 17 mm. The minimum outer diameter BD3 is preferably equal to or less than 19 mm. In this embodiment, the minimum outer diameter BD3 of the hub axle 30 is 17.6 mm.However, the minimum outer diameter BD3 is not limited to this embodiment and the aforementioned areas.

[0124] The hub axle 30 comprises an axle tube 30X, a first axle section 30Y, and a second axle section 30Z. The axle tube 30X has a tubular shape and extends along the pivot axis A1. The first axle section 30Y is attached to a first end of the axle tube 30X. The second axle section 30Z is attached to a second end of the axle tube 30X. At least one of the first axle section 30Y and the second axle section 30Z can be integrally formed with the axle tube 30X.

[0125] As can be seen in Figures 3 and 4, the rear bicycle hub assembly 12 further comprises a brake rotor support body 34. The brake rotor support body 34 is rotatably mounted on the hub axle 30 about the pivot axis A1. The brake rotor support body 34 is connected to the bicycle brake rotor 16 ( Fig. 1) connected to transmit a braking torque from the bicycle brake rotor 16 to the brake rotor support body 34.

[0126] As in Fig. As shown in Figure 4, the rear bicycle hub assembly 12 comprises a hub body 36. The hub body 36 is rotatably mounted on the hub axle 30 about the pivot axis A1 of the rear bicycle hub assembly 12. In this embodiment, the sprocket support body 28 is a separate element from the hub body 36. The brake rotor support body 34 is integrally formed with the hub body 36 as a single, unified element. However, the sprocket support body 28 can also be integrally formed with the hub body 36. The brake rotor support body 34 can be a separate element from the hub body 36. The hub body 36 is, for example, made of a metallic material, such as aluminum.

[0127] As in Fig. As shown in Figure 5, the rear bicycle chainring assembly 14 comprises several bicycle chainrings. The several bicycle chainrings include a first chainring and a second chainring. In this embodiment, the several bicycle chainrings include several first chainrings SP1 and SP2, which are designated as the first chainring. The several bicycle chainrings also include several second chainrings SP3 and SP4, which are designated as the second chainring. The several bicycle chainrings include an additional chainring. In this embodiment, the several bicycle chainrings include several additional chainrings SP5 to SP12. However, the total number of first chainrings is not limited to this embodiment. The total number of second chainrings is not limited to this embodiment. The total number of additional chainrings is not limited to this embodiment.Furthermore, the first sprockets SP1 and SP2 can be formed integrally as a single, one-piece element, whereas in this embodiment, the first sprocket SP1 is a sprocket separate from the first sprocket SP2. Similarly, the second sprockets SP3 and SP4 can be formed integrally as a single, one-piece element, whereas in this embodiment, the second sprocket SP3 is a sprocket separate from the second sprocket SP4.

[0128] For example, the total number of multiple bicycle chainrings can be equal to or greater than 10. The total number of multiple bicycle chainrings can be equal to or greater than 11. The total number of multiple bicycle chainrings can be equal to or greater than 12. In this embodiment, the total number of bicycle chainrings is 12. However, the total number of bicycle chainrings is not limited to this embodiment. For example, the total number of multiple bicycle chainrings can be 13, 14, or equal to or greater than 15.

[0129] In this embodiment, the first sprocket SP1 is the smallest sprocket in the rear bicycle sprocket assembly 14. The additional sprocket SP12 is the largest sprocket in the rear bicycle sprocket assembly 14. The first sprocket SP2 corresponds to the highest gear in the rear bicycle sprocket assembly 14. The additional sprocket SP12 corresponds to a low gear in the rear bicycle sprocket assembly 14.

[0130] As in Fig. As shown in Figure 5, the first sprocket SP1 has a pitch circle diameter PCD1. The first sprocket SP2 has a pitch circle diameter PCD2. The second sprocket SP3 has a pitch circle diameter PCD3. The second sprocket SP4 has a pitch circle diameter PCD4. The additional sprocket SP5 has a pitch circle diameter PCD5. The additional sprocket SP6 has a pitch circle diameter PCD6. The additional sprocket SP7 has a pitch circle diameter PCD7. The additional sprocket SP8 has a pitch circle diameter PCD8. The additional sprocket SP9 has a pitch circle diameter PCD9. The additional sprocket SP10 has a pitch circle diameter PCD10. The additional sprocket SP11 has a pitch circle diameter PCD11. The additional sprocket SP12 has a pitch circle diameter PCD12.

[0131] The first sprocket SP1 has a pitch circle PC1 with a pitch circle diameter PCD1. The first sprocket SP2 has a pitch circle PC2 with a pitch circle diameter PCD2. The second sprocket SP3 has a pitch circle PC3 with a pitch circle diameter PCD3. The second sprocket SP4 has a pitch circle PC4 with a pitch circle diameter PCD4. The additional sprocket SP5 has a pitch circle PC5 with a pitch circle diameter PCD5. The additional sprocket SP6 has a pitch circle PC6 with a pitch circle diameter PCD6. The additional sprocket SP7 has a pitch circle PC7 with a pitch circle diameter PCD7. The additional sprocket SP8 has a pitch circle PC8 with a pitch circle diameter PCD8. The additional sprocket SP9 has a pitch circle PC9 with a pitch circle diameter PCD9. The additional sprocket SP10 has a pitch circle PC10 with a pitch circle diameter PCD10.The additional sprocket SP11 comprises a pitch circle PC11 with a pitch circle diameter PCD11. The additional sprocket SP12 comprises a pitch circle PC12 with a pitch circle diameter PCD12.

[0132] The pitch circle PC1 of the first sprocket SP1 is defined by the center axes of pins of the bicycle chain 20 ( Fig. 2) defined, which engage with the first sprocket SP1. The pitch circles PC2 to PC12 are defined in the same way as the pitch circle PC1. Therefore, for the sake of brevity, they are not described in detail here.

[0133] In this embodiment, the pitch circle diameter PCD1 is smaller than the pitch circle diameter PCD2. The pitch circle diameter PCD2 is smaller than the pitch circle diameter PCD3. The pitch circle diameter PCD3 is smaller than the pitch circle diameter PCD4. The pitch circle diameter PCD4 is smaller than the pitch circle diameter PCD5. The pitch circle diameter PCD5 is smaller than the pitch circle diameter PCD6. The pitch circle diameter PCD6 is smaller than the pitch circle diameter PCD7. The pitch circle diameter PCD7 is smaller than the pitch circle diameter PCD8. The pitch circle diameter PCD8 is smaller than the pitch circle diameter PCD9. The pitch circle diameter PCD9 is smaller than the pitch circle diameter PCD10. The pitch circle diameter PCD10 is smaller than the pitch circle diameter PCD11. The pitch circle diameter PCD11 is smaller than the pitch circle diameter PCD12.

[0134] The pitch circle diameter PCD1 is the smallest pitch circle diameter in the rear bicycle chainring assembly 14. The pitch circle diameter PCD12 is the largest pitch circle diameter in the rear bicycle chainring assembly 14. The first chainring SP1 corresponds to a high gear in the bicycle chainring assembly 14. The additional chainring SP12 corresponds to a low gear in the rear bicycle chainring assembly 14. However, the first chainring SP1 can correspond to a different gear in the rear bicycle chainring assembly 14. The additional chainring SP12 can correspond to a different gear in the rear bicycle chainring assembly 14.

[0135] As in Fig. As shown in Figure 6, the first sprocket SP2 is adjacent to the first sprocket SP1 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any other sprocket between the first sprockets SP1 and SP2. The second sprocket SP3 is adjacent to the first sprocket SP2 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any other sprocket between the first sprocket SP2 and the second sprocket SP3. The second sprocket SP4 is adjacent to the second sprocket SP3 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any other sprocket between the second sprocket SP3 and the second sprocket SP4. The first sprockets SP1 and SP2, the second sprocket SP3, the second sprocket SP4, and the additional sprockets SP5 to SP12 are arranged in this order in the axial direction D2.

[0136] As in Fig. As shown in Figure 7, the first sprocket SP1 comprises a sprocket body SP1A and several sprocket teeth SP1B. The several sprocket teeth SP1B extend radially outward from the sprocket body SP1A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. The total number of teeth of the first sprocket SP1 (the total number of the at least one sprocket tooth SP1B) is equal to or less than 10. In this embodiment, the total number of the at least one sprocket tooth SP1B of the first sprocket SP1 is 10. However, the total number of the several sprocket teeth SP1B of the first sprocket SP1 is not limited to this embodiment and the preceding section.

[0137] As in Fig. As shown in Figure 8, the first sprocket SP2 comprises a sprocket body SP2A and several sprocket teeth SP2B. The several sprocket teeth SP2B extend radially outwards from the sprocket body SP2A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP2B is 12. However, the total number of the several sprocket teeth SP2B of the first sprocket SP2 is not limited to this embodiment.

[0138] The first sprocket SP2 comprises at least one first shifting drive area SP2F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the first sprocket SP2 to the first sprocket SP1. The first sprocket SP2 comprises at least one second shifting drive area SP2F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the first sprocket SP1 to the first sprocket SP2. In this embodiment, the first sprocket SP2 comprises multiple first shifting drive areas SP2F1 to facilitate the first shifting operation. The first sprocket SP2 comprises a second shifting drive area SP2F2 to facilitate the second shifting operation. However, the total number of first shifting drive areas SP2F1 is not limited to this embodiment. The total number of second shifting drive areas SP2F2 is not limited to this embodiment.The term "shifting conveyor area" used here is intended to be an area that is intentionally designed to facilitate the shifting of a bicycle chain from one sprocket to another axially adjacent sprocket in that area.

[0139] In this embodiment, the first sprocket SP2 includes several first shift feed recesses SP2R1 to facilitate the first shifting operation. The first sprocket SP2 includes several second shift feed recesses SP2R2 to facilitate the second shifting operation. The first shift feed recess SP2R1 is provided in the first shift feed area SP2F1. However, the first shift feed area SP2F1 may contain a different structure instead of, or in addition to, the first shift feed recess SP2R1. The second shift feed area SP2F2 may contain a different structure instead of, or in addition to, the second shift feed recess SP2R2.

[0140] As in Fig. As shown in Figure 9, the second sprocket SP3 comprises a sprocket body SP3A and several sprocket teeth SP3B. The several sprocket teeth SP3B extend radially outwards from the sprocket body SP3A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP3B is 14. The total number of the several sprocket teeth SP3B of the second sprocket SP3 is not limited to this embodiment.

[0141] The second sprocket SP3 includes at least one first shifting area SP3F1 to facilitate a first shifting operation in which the bicycle chain moves 20 from the second sprocket SP3 to the first sprocket SP2 ( Fig. 6) changes. The second sprocket SP3 includes at least one second shifting area SP3F2 to facilitate a second shifting operation in which the bicycle chain moves 20 from the first sprocket SP2 ( Fig. 6) to the second sprocket SP3. In this embodiment, the second sprocket SP3 comprises several first shifting feed areas SP3F1 to facilitate the first shifting operation. The second sprocket SP3 comprises a second shifting feed area SP3F2 to facilitate the second shifting operation. However, the total number of first shifting feed areas SP3F1 is not limited to this embodiment. The total number of second shifting feed areas SP3F2 is not limited to this embodiment.

[0142] In this embodiment, the second sprocket SP3 includes several first shift feed recesses SP3R1 to facilitate the first shifting operation. The second sprocket SP3 includes several second shift feed recesses SP3R2 to facilitate the second shifting operation. The first shift feed recess SP3R1 is provided in the first shift feed area SP3F1. However, the first shift feed area SP3F1 may contain a different structure instead of, or in addition to, the first shift feed recess SP3R1. The second shift feed area SP3F2 may contain a different structure instead of, or in addition to, the second shift feed recess SP3R2.

[0143] As in Fig. As shown in Figure 10, the second sprocket SP4 comprises a sprocket body SP4A and several sprocket teeth SP4B. The several sprocket teeth SP4B extend radially outwards from the sprocket body SP4A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP4B is 16. However, the total number of the several sprocket teeth SP4B of the second sprocket SP4 is not limited to this embodiment.

[0144] The second sprocket SP4 comprises at least one first shifting drive area SP4F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the second sprocket SP4 to the second sprocket SP3. The second sprocket SP4 comprises at least one second shifting drive area SP4F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the second sprocket SP3 to the second sprocket SP4. In this embodiment, the second sprocket SP4 comprises multiple first shifting drive areas SP4F1 to facilitate the first shifting operation. The second sprocket SP4 comprises a second shifting drive area SP4F2 to facilitate the second shifting operation. However, the total number of first shifting drive areas SP4F1 is not limited to this embodiment. The total number of second shifting drive areas SP4F2 is not limited to this embodiment.

[0145] In this embodiment, the second sprocket SP4 includes several first shift feed recesses SP4R1 to facilitate the first shifting operation. The second sprocket SP4 includes several second shift feed recesses SP4R2 to facilitate the second shifting operation. The first shift feed recess SP4R1 is provided in the first shift feed area SP4F1. However, the first shift feed area SP4F1 may contain a different structure instead of, or in addition to, the first shift feed recess SP4R1. The second shift feed area SP4F2 may contain a different structure instead of, or in addition to, the second shift feed recess SP4R2.

[0146] As in Fig. As shown in Figure 11, the additional sprocket SP5 comprises a sprocket body SP5A and several sprocket teeth SP5B. The several sprocket teeth SP5B extend radially outward from the sprocket body SP5A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP5B is 18. However, the total number of the several sprocket teeth SP5B of the additional sprocket SP5 is not limited to this embodiment.

[0147] The additional sprocket SP5 comprises at least one first shifting drive area SP5F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP5 to the adjacent smaller sprocket SP4. The additional sprocket SP5 comprises at least one second shifting drive area SP5F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP4 to the additional sprocket SP5. The adjacent smaller sprocket SP4 is adjacent to the additional sprocket SP5 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP5 and the adjacent smaller sprocket SP4. In this embodiment, the additional sprocket SP5 comprises multiple first shifting drive areas SP5F1 to facilitate the first shifting operation.The additional sprocket SP5 includes several second shift feed areas SP5F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP5F1 is not limited to this embodiment. The total number of second shift feed areas SP5F2 is also not limited to this embodiment.

[0148] In this embodiment, the additional sprocket SP5 includes several first shift feed recesses SP5R1 to facilitate the first shifting operation. The additional sprocket SP5 includes several second shift feed recesses SP5R2 to facilitate the second shifting operation. The first shift feed recess SP5R1 is provided in the first shift feed area SP5F1. The second shift feed recess SP5R2 is provided in the second shift feed area SP5F2. However, the first shift feed area SP5F1 may contain a different structure instead of, or in addition to, the first shift feed recess SP5R1. The second shift feed area SP5F2 may contain a different structure instead of, or in addition to, the second shift feed recess SP5R2.

[0149] As in Fig. As shown in Figure 12, the additional sprocket SP6 comprises a sprocket body SP6A and several sprocket teeth SP6B. The several sprocket teeth SP6B extend radially outward from the sprocket body SP6A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP6B is 21. However, the total number of the several sprocket teeth SP6B of the additional sprocket SP6 is not limited to this embodiment.

[0150] The additional sprocket SP6 comprises at least one first shifting drive area SP6F1 to facilitate a first shifting operation in which the bicycle chain 20 moves from the additional sprocket SP6 to the adjacent smaller sprocket SP5. The additional sprocket SP6 comprises at least one second shifting drive area SP6F2 to facilitate a second shifting operation in which the bicycle chain 20 moves from the adjacent smaller sprocket SP5 to the additional sprocket SP6. The adjacent smaller sprocket SP5 is adjacent to the additional sprocket SP6 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP6 and the adjacent smaller sprocket SP5. In this embodiment, the additional sprocket SP6 comprises multiple first shifting drive areas SP6F1 to facilitate the first shifting operation.The additional sprocket SP6 includes several second shift feed areas SP6F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP6F1 is not limited to this embodiment. The total number of second shift feed areas SP6F2 is also not limited to this embodiment.

[0151] In this embodiment, the additional sprocket SP6 includes several first shift feed recesses SP6R1 to facilitate the first shifting operation. The additional sprocket SP6 has several second shift feed recesses SP6R2 to facilitate the second shifting operation. The first shift feed recess SP6R1 is provided in the first shift feed area SP6F1. The second shift feed recess SP6R2 is provided in the second shift feed area SP6F2. However, the first shift feed area SP6F1 may contain a different structure instead of, or in addition to, the first shift feed recess SP6R1. The second shift feed area SP6F2 may contain a different structure instead of, or in addition to, the second shift feed recess SP6R2.

[0152] As in Fig. As shown in Figure 13, the additional sprocket SP7 comprises a sprocket body SP7A and several sprocket teeth SP7B. The several sprocket teeth SP7B extend radially outward from the sprocket body SP7A with respect to the pivot axis A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP7B is 24. However, the total number of the several sprocket teeth SP7B of the additional sprocket SP7 is not limited to this embodiment.

[0153] The additional sprocket SP7 comprises at least one first shifting drive area SP7F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP7 to the adjacent smaller sprocket SP6. The additional sprocket SP7 comprises at least one second shifting drive area SP7F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP6 to the additional sprocket SP7. The adjacent smaller sprocket SP6 is adjacent to the additional sprocket SP7 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP7 and the adjacent smaller sprocket SP6. In this embodiment, the additional sprocket SP7 comprises multiple first shifting drive areas SP7F1 to facilitate the first shifting operation.The additional sprocket SP7 includes several second shift feed areas SP7F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP7F1 is not limited to this embodiment. The total number of second shift feed areas SP7F2 is also not limited to this embodiment.

[0154] In this embodiment, the additional sprocket SP7 includes several first shift feed recesses SP7R1 to facilitate the first shifting operation. The additional sprocket SP7 includes several second shift feed recesses SP7R2 to facilitate the second shifting operation. The first shift feed recess SP7R1 is provided in the first shift feed area SP7F1. The second shift feed recess SP7R2 is provided in the second shift feed area SP7F2. However, the first shift feed area SP7F1 may have a different structure instead of, or in addition to, the first shift feed recess SP7R1. The second shift feed area SP7F2 may have a different structure instead of, or in addition to, the second shift feed recess SP7R2.

[0155] As in Fig. As shown in Figure 14, the additional sprocket SP8 comprises a sprocket body SP8A and several sprocket teeth SP8B. The several sprocket teeth SP8B extend radially outwards from the sprocket body SP8A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP8B is 28. However, the total number of the several sprocket teeth SP8B of the additional sprocket SP8 is not limited to this embodiment.

[0156] The additional sprocket SP8 comprises at least one first shifting drive area SP8F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP8 to the adjacent smaller sprocket SP7. The additional sprocket SP8 comprises at least one second shifting drive area SP8F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP7 to the additional sprocket SP8. The adjacent smaller sprocket SP7 is adjacent to the additional sprocket SP8 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP8 and the adjacent smaller sprocket SP7. In this embodiment, the additional sprocket SP8 comprises multiple first shifting drive areas SP8F1 to facilitate the first shifting operation.The additional sprocket SP8 includes several second shift feed areas SP8F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP8F1 is not limited to this embodiment. The total number of second shift feed areas SP8F2 is also not limited to this embodiment.

[0157] In this embodiment, the additional sprocket SP8 includes several first shift feed recesses SP8R1 to facilitate the first shifting operation. The additional sprocket SP8 includes several second shift feed recesses SP8R2 to facilitate the second shifting operation. The first shift feed recess SP8R1 is provided in the first shift feed area SP8F1. The second shift feed recess SP8R2 is provided in the second shift feed area SP8F2. However, the first shift feed area SP8F1 may have a different structure instead of, or in addition to, the first shift feed recess SP8R1. The second shift feed area SP8F2 may have a different structure instead of, or in addition to, the second shift feed recess SP8R2.

[0158] As in Fig. As shown in Figure 15, the additional sprocket SP9 comprises a sprocket body SP9A and several sprocket teeth SP9B. The several sprocket teeth SP9B extend radially outward from the sprocket body SP9A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP9B is 33. However, the total number of the several sprocket teeth SP9B of the additional sprocket SP9 is not limited to this embodiment.

[0159] The additional sprocket SP9 comprises at least one first shifting drive area SP9F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP9 to the adjacent smaller sprocket SP8. The additional sprocket SP9 comprises at least one second shifting drive area SP9F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP8 to the additional sprocket SP9. The adjacent smaller sprocket SP8 is adjacent to the additional sprocket SP9 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP9 and the adjacent smaller sprocket SP8. In this embodiment, the additional sprocket SP9 comprises multiple first shifting drive areas SP9F1 to facilitate the first shifting operation.The additional sprocket SP9 includes several second shift feed areas SP9F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP9F1 is not limited to this embodiment. The total number of second shift feed areas SP9F2 is also not limited to this embodiment.

[0160] In this embodiment, the additional sprocket SP9 includes several first shift feed recesses SP9R1 to facilitate the first shifting operation. The additional sprocket SP9 includes several second shift feed recesses SP9R2 to facilitate the second shifting operation. The first shift feed recess SP9R1 is provided in the first shift feed area SP9F1. The second shift feed recess SP9R2 is provided in the second shift feed area SP9F2. However, the first shift feed area SP9F1 may have a different structure instead of, or in addition to, the first shift feed recess SP9R1. The second shift feed area SP9F2 may have a different structure instead of, or in addition to, the second shift feed recess SP9R2.

[0161] As in Fig. As shown in Figure 16, the additional sprocket SP10 comprises a sprocket body SP10A and several sprocket teeth SP10B. The several sprocket teeth SP10B extend radially outward from the sprocket body SP10A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP10B is 39. However, the total number of the several sprocket teeth SP10B of the additional sprocket SP10 is not limited to this embodiment.

[0162] The additional sprocket SP10 comprises at least one first shifting drive area SP10F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP10 to the adjacent smaller sprocket SP9. The additional sprocket SP10 comprises at least one second shifting drive area SP10F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP9 to the additional sprocket SP10. The adjacent smaller sprocket SP9 is adjacent to the additional sprocket SP10 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP10 and the adjacent smaller sprocket SP9. In this embodiment, the additional sprocket SP10 comprises multiple first shifting drive areas SP10F1 to facilitate the first shifting operation.The additional sprocket SP10 includes several second shift feed areas SP10F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP10F1 is not limited to this embodiment. The total number of second shift feed areas SP10F2 is also not limited to this embodiment.

[0163] In this embodiment, the additional sprocket SP10 includes several first shift feed recesses SP10R1 to facilitate the first shifting operation. The additional sprocket SP10 includes several second shift feed recesses SP10R2 to facilitate the second shifting operation. The first shift feed recess SP10R1 is provided in the first shift feed area SP10F1. The second shift feed recess SP10R2 is provided in the second shift feed area SP10F2. However, the first shift feed area SP10F1 may have a different structure instead of, or in addition to, the first shift feed recess SP10R1. The second shift feed area SP10F2 may have a different structure instead of, or in addition to, the second shift feed recess SP10R2.

[0164] As in Fig. As shown in Figure 17, the additional sprocket SP11 comprises a sprocket body SP11A and several sprocket teeth SP11B. The several sprocket teeth SP11B extend radially outward from the sprocket body SP11A with respect to the central axis of rotation A1 of the rear bicycle sprocket assembly 14. In this embodiment, the total number of the at least one sprocket tooth SP11B is 45. However, the total number of the several sprocket teeth SP11B of the additional sprocket SP11 is not limited to this embodiment.

[0165] The additional sprocket SP11 comprises at least one first shifting drive area SP11F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP11 to the adjacent smaller sprocket SP10. The additional sprocket SP11 comprises at least one second shifting drive area SP11F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP10 to the additional sprocket SP11. The adjacent smaller sprocket SP10 is adjacent to the additional sprocket SP11 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP11 and the adjacent smaller sprocket SP10. In this embodiment, the additional sprocket SP11 comprises multiple first shifting drive areas SP11F1 to facilitate the first shifting operation.The additional sprocket SP11 includes several second shift feed areas SP11F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP11F1 is not limited to this embodiment. The total number of second shift feed areas SP11F2 is also not limited to this embodiment.

[0166] In this embodiment, the additional sprocket SP11 includes several first shift feed recesses SP11R1 to facilitate the first shifting operation. The additional sprocket SP11 includes several second shift feed recesses SP11R2 to facilitate the second shifting operation. The first shift feed recess SP11R1 is provided in the first shift feed area SP11F1. The second shift feed recess SP11R2 is provided in the second shift feed area SP11F2. However, the first shift feed area SP11F1 may have a different structure instead of, or in addition to, the first shift feed recess SP11R1. The second shift feed area SP11F2 may have a different structure instead of, or in addition to, the second shift feed recess SP11R2.

[0167] As in Fig. As shown in Figure 18, the additional sprocket SP12 comprises a sprocket body SP12A and several sprocket teeth SP12B. The several sprocket teeth SP12B extend radially outward from the sprocket body SP12A with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. The total number of teeth of the additional sprocket SP12 is equal to or greater than 46. The total number of teeth of the additional sprockets SP12 can also be equal to or greater than 50. In this embodiment, the total number of teeth of the additional sprocket SP12 is 51. However, the total number of the at least one sprocket tooth SP12B of the additional sprocket SP12 is not limited to this embodiment and the preceding sections.

[0168] The additional sprocket SP12 comprises at least one first shifting drive area SP12F1 to facilitate a first shifting operation in which the bicycle chain 20 shifts from the additional sprocket SP12 to an adjacent smaller sprocket SP11. The additional sprocket SP12 comprises at least one second shifting drive area SP12F2 to facilitate a second shifting operation in which the bicycle chain 20 shifts from the adjacent smaller sprocket SP11 to the additional sprocket SP12. The adjacent smaller sprocket SP11 is adjacent to the additional sprocket SP12 in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14, without any further sprocket between the additional sprocket SP12 and the adjacent smaller sprocket SP11. In this embodiment, the additional sprocket SP12 comprises multiple first shifting drive areas SP12F1 to facilitate the first shifting operation.The additional sprocket SP12 includes several second shift feed areas SP12F2 to facilitate the second shifting operation. However, the total number of first shift feed areas SP12F1 is not limited to this embodiment. The total number of second shift feed areas SP12F2 is also not limited to this embodiment.

[0169] In this embodiment, the additional sprocket SP12 includes several first shift feed recesses SP12R1 to facilitate the first shifting operation. The additional sprocket SP12 includes several second shift feed recesses SP12R2 to facilitate the second shifting operation. The first shift feed recess SP12R1 is provided in the first shift feed area SP12F1. The second shift feed recess SP12R2 is provided in the second shift feed area SP12F2. However, the first shift feed area SP12F1 may have a different structure instead of, or in addition to, the first shift feed recess SP12R1. The second shift feed area SP12F2 may have a different structure instead of, or in addition to, the second shift feed recess SP12R2.

[0170] As in Fig. As shown in Figure 19, the sprockets SP1 to SP12 are separate elements. However, at least one of the sprockets SP1 to SP12 can be at least partially integrally formed with another of the sprockets SP1 to SP12. All sprockets SP1 to SP12 can be formed as a single unit. In such a case, at least one of the sprockets SP3 to SP12 can have at least ten internal spline or internal key teeth.

[0171] The rear bicycle sprocket assembly 14 further comprises a sprocket support element 37, several spacers 38, a first ring 39A, and a second ring 39B. The first ring 39A is positioned axially D2 between the second sprocket SP3 and the second sprocket SP4. The second ring 39B is positioned axially D2 between the second sprocket SP4 and the additional sprocket SP5. The additional sprocket is designed to be attached to the sprocket support element 37. In this embodiment, the additional sprockets SP5 to SP12 are also designed to be attached to the sprocket support element 37.

[0172] As in Fig. As shown in Figure 6, the additional sprocket is attached to the sprocket support element 37, for example, by an adhesive 37A. In this embodiment, the additional sprockets SP5 to SP12 are attached to the sprocket support element 37 by the adhesive 37A. This makes it possible to reduce the weight of the rear bicycle sprocket assembly 14 by reducing or eliminating metallic fasteners. However, at least one of the additional sprockets SP5 to SP12 can be attached to the sprocket support element 37 with a different structure (including a metallic fastener) than the adhesive 37A. At least one of the additional sprockets SP5 to SP12 can engage with the sprocket support body 28 without the sprocket support element 37. The sprocket support element 37 can be omitted from the rear bicycle sprocket assembly 14.Furthermore, at least one of the second sprockets SP3 and SP4 can be attached to the sprocket support element 37.

[0173] As in Fig. As shown in Figure 4, the locking element 32 comprises a tubular body 32A, an externally threaded section 32B, and a radial projection 32C. The tubular body 32A includes a first axial end 32D and a second axial end 32E. The second axial end 32E is arranged in the axial direction D2 with respect to the rotational center axis A1 of the rear bicycle chainring assembly 14 relative to the first axial end 32D. As shown in Figure 4, the locking element 32 comprises a tubular body 32A, an externally threaded section 32B, and a radial projection 32C. The second axial end 32E is arranged in the axial direction D2 relative to the rotational center axis A1 of the rear bicycle chainring assembly 14 relative to the first axial end 32D. Fig. As can be seen in Figure 6, the first axial end 32D is positioned closer to an axial median plane CPL of the rear bicycle hub assembly 12 than the second axial end 32E in a state where the rear bicycle chainring assembly 14 is attached to the rear bicycle hub assembly 12. The axial median plane CPL is perpendicular to the rotational center axis A1. As shown in Fig. As can be seen in Figure 3, the axial median plane CPL is defined such that it bisects an axial length of the rear bicycle hub assembly 12 in the axial direction D2.

[0174] As in Fig. As shown in Figure 6, the external threaded section 32B is provided at the first axial end 32D to engage with an internal threaded section 28A of the sprocket support body 28 of the rear bicycle hub assembly 12 in the state in which the rear bicycle sprocket assembly 14 is attached. The radial projection 32C extends radially outward from the second axial end 32E with respect to the axis of rotation A1 to restrict axial movement of the first sprocket SP2 relative to the sprocket support body 28 of the rear bicycle hub assembly 12 in the state in which the rear bicycle sprocket assembly 14 is attached to the rear bicycle hub assembly 12.

[0175] The first sprocket SP1 comprises a first inwardly facing side SP1G and a first outwardly facing side SP1H. The first outwardly facing side SP1H is opposite the first inwardly facing side SP1G in the axial direction D2. The radial projection 32C is positioned to abut the first outwardly facing side SP1H of the first sprocket SP1. The first sprockets SP1 and SP2 are arranged in the axial direction between the radial projection 32C and the second sprocket SP3. The first sprockets SP1 and SP2, the second sprocket SP3, the second sprocket SP4, and the first ring 39A are held in the axial direction D2 between the radial projection 32C and the sprocket support element 37.

[0176] As in Fig. As shown in Figure 4, the locking element 32 has a tool engagement section 32F. The tool engagement section 32F is provided on an inner circumferential surface 32A1 of the tubular body 32A to engage with a locking tool (not shown). In this embodiment, the tool engagement section 32F comprises several engagement grooves 32G that engage with the locking tool when the locking element 32 engages with the external threaded section 32B and the internal threaded section 28A with the sprocket support body 28.

[0177] As in Fig. 20 and Fig. As can be seen in Figure 21, the sprocket support body 28 has at least one external spline or external keyway tooth 40 which is designed to engage with the rear bicycle sprocket assembly 14 ( Fig. 6) to engage. The sprocket support body 28 comprises at least ten external splined teeth 40, which are arranged to engage with the rear bicycle sprocket assembly 14 ( Fig. 6) come into / are involved. That is, the at least one external wedge tooth 40 encompasses several external wedge teeth 40.

[0178] The sprocket support body 28 comprises a base carrier 41 with a tubular shape. The base carrier 41 extends along the axis of rotation A1. The external sprocket tooth 40 extends radially outward from the base carrier 41. The sprocket support body 28 comprises a larger-diameter section 42, a flange 44, and several helical external sprocket teeth 46. The larger-diameter section 42 and the flange 44 extend radially outward from the base carrier 41. The larger-diameter section 42 is positioned in the axial direction D2 between the several external sprocket teeth 40 and the flange 44. The larger-diameter section 42 and the flange 44 are positioned in the axial direction D2 between the several external sprocket teeth 40 and the several helical external sprocket teeth 46. As shown in Fig. As shown in Figure 6, the rear bicycle chainring assembly 14 is held in the axial direction D2 between the larger-diameter part 42 and the radial projection 32C of the locking element 32. The larger-diameter part 42 may have an internal cavity, allowing a drive structure, such as a one-way coupling structure, to be contained within the internal cavity. The larger-diameter part 42 can be omitted from the rear bicycle hub assembly 12 if required.

[0179] As in Fig. As shown in Figure 22, at least one of the at least ten external spline teeth 40 has an axial spline or spline tooth length SL1. Each of the external spline teeth 40 has the axial spline or spline tooth length SL1. The axial spline tooth length SL1 is equal to or less than 27 mm. The axial spline tooth length SL1 is equal to or greater than 22 mm. In this embodiment, the axial spline tooth length SL1 is 24.9 mm. However, the axial spline tooth length SL1 is not limited to this embodiment and the preceding range.

[0180] As in Fig. As shown in Figure 23, the total number of the at least ten external wedge teeth 40 is equal to or greater than 20. The total number of the at least ten external wedge teeth 40 is preferably equal to or greater than 25. The total number of the at least ten external wedge teeth 40 is preferably equal to or greater than 28. The total number of external wedge teeth 40 is preferably equal to or less than 72. In this embodiment, the total number of external wedge teeth 40 is 29. However, the total number of external wedge teeth 40 is not limited to this embodiment and the preceding sections.

[0181] The at least ten external spline teeth 40 have a first outer helix angle PA11 and a second outer helix angle PA12. At least two of the at least ten external spline teeth 40 are arranged circumferentially with respect to the first outer pressure angle PA11 relative to the axis of rotation A1. In other words, at least two of the multiple external spline teeth 40 are arranged circumferentially at the first outer pressure angle PA11 relative to the axis of rotation A1 of the rear bicycle hub assembly 12. At least two of the at least ten external spline teeth 40 are arranged circumferentially at the second outer helix angle PA12 relative to the axis of rotation A1 of the rear bicycle hub assembly 12. In other words, at least two of the multiple external spline teeth 40 are arranged circumferentially at the second outer helix angle PA12 relative to the axis of rotation A1 of the rear bicycle hub assembly 12.In this embodiment, the second outer slope angle PA12 differs from the first outer slope angle PA11. However, the second outer slope angle PA12 can be essentially the same as the first outer slope angle PA11.

[0182] In this embodiment, the outer spline teeth 40 are arranged at the first outer helix angle PA11 in the circumferential direction D1. Two outer spline teeth of the outer spline teeth 40 are arranged at the second outer helix angle PA12 in the circumferential direction D1. However, at least two outer spline teeth of the outer spline teeth 40 can be arranged at a different outer helix angle in the circumferential direction D1.

[0183] The first outer slope angle PA11 is in the range of 5 degrees to 36 degrees. The first outer slope angle PA11 is preferably in the range of 10 degrees to 20 degrees. The first outer slope angle PA11 is preferably equal to or less than 15 degrees. In this embodiment, the first outer slope angle PA11 is 12 degrees. However, the first outer slope angle PA11 is not limited to this embodiment and the aforementioned ranges.

[0184] The second outer slope angle PA12 lies in the range of 5 degrees to 36 degrees. In this embodiment, the second outer slope angle PA12 is 24 degrees. However, the second outer slope angle PA12 is not limited to this embodiment and the aforementioned range.

[0185] At least one of the external spline teeth 40 can have a first spline or spline shape that differs from a second spline shape of another of the external spline teeth 40. At least one of the at least ten external spline teeth 40 can have a first spline or spline size that differs from a second spline size of another of the at least ten external spline teeth 40. At least one of the external spline teeth 40 comprises a profile that, when viewed along the axis of rotation A1, differs from a profile of another of the external spline teeth 40. In this embodiment, the external spline tooth 40X comprises the first spline shape that differs from the second spline shape of another of the external spline teeth 40.The external splined tooth 40X has a first splined dimension that differs from the second splined dimension of any other external splined tooth 40. As in . Fig. As can be seen in figure 24, the at least ten external spline teeth 40 can have the same spline shape. The at least ten external spline teeth 40 can have the same spline size. The at least ten external spline teeth 40 can have the same profile.

[0186] As in Fig. As can be seen in Figure 25, each of the at least ten external spline teeth 40 has an external spline or external spline drive surface 48 and an external spline or external spline non-drive surface 50. The multiple external spline teeth 40 comprise multiple external spline drive surfaces 48 for receiving the drive torque F1 from the rear bicycle chainring assembly 14 ( Fig. 6) during pedaling. The multiple external splined teeth 40 comprise multiple external splined non-drive surfaces 50. The external splined drive surface 48 can be brought into contact with the rear sprocket chain assembly 14 to receive the drive torque F1 from the rear bicycle sprocket assembly 14 during pedaling ( Fig. 6) The external splined drive surface 48 faces the reverse direction of rotation D12. The external splined drive surface 48 faces an internal splined drive surface 66 of the rear bicycle chainring assembly 14 in a state in which the rear bicycle chainring assembly 14 is attached to the rear bicycle hub assembly 12. The external splined non-drive surface 50 is provided in the circumferential direction D1 on a rear side of the external splined drive surface 48. The external splined non-drive surface 50 faces the drive direction of rotation D11 in order to avoid receiving the drive torque F1 from the rear bicycle chainring assembly 14 during pedaling. The external splined non-drive surface 50 faces an internal splined non-drive surface 68 of the rear bicycle chainring assembly 14 in a state in which the rear bicycle chainring assembly 14 is attached to the rear bicycle hub assembly 12.

[0187] The at least ten external spline teeth 40 each have maximum circumferential widths MW1. The maximum circumferential width MW1 is defined as the maximum width to accommodate a compressive force F2 applied to the external spline tooth 40. The maximum circumferential width MW1 is defined as a straight distance based on the external spline drive surface 48.

[0188] The multiple external splined drive surfaces 48 each have a radially outermost edge 48A and a radially innermost edge 48B. The external splined drive surface 48 extends from the radially outermost edge 48A to the radially innermost edge 48B. A first reference circle RC11 is defined at the radially innermost edge 48B and is centered on the axis of rotation A1. The first reference circle RC11 intersects the external splined non-drive surface 50 at a reference point 50R. The maximum circumferential width MW1 extends directly from the radially innermost edge 48B to the reference point 50R in the circumferential direction D1.

[0189] The multiple external splined non-drive surfaces 50 each have a radially outermost edge 50A and a radially innermost edge 50B. The external splined non-drive surface 50 extends from the radially outermost edge 50A to the radially innermost edge 50B. In this embodiment, the reference point 50R coincides with the radially innermost edge 50B. However, the reference point 50R can be offset from the radially innermost edge 50B.

[0190] The sum of the maximum circumferential widths MW1 is equal to or greater than 55 mm. The sum of the maximum circumferential widths MW1 is preferably equal to or greater than 60 mm. The sum of the maximum circumferential widths MW1 is preferably equal to or less than 70 mm. In this embodiment, the sum of the maximum circumferential widths MW1 is 60.1 mm. However, the sum of the maximum circumferential widths MW1 is not limited to this embodiment and the aforementioned ranges.

[0191] As in Fig. As shown in Figure 26, the at least one external spline tooth 40 has an external spline or external spline main diameter DM11 that is equal to or less than 34 mm. The external spline main diameter DM11 is equal to or less than 33 mm. The external spline main diameter DM11 is equal to or greater than 29 mm. In this embodiment, the external spline main diameter DM11 is 32.6 mm. However, the external spline main diameter DM11 is not limited to this embodiment and the aforementioned ranges.

[0192] The at least one external spline tooth 40 comprises an external spline or external spline secondary diameter DM12. The at least one external spline tooth 40 comprises an external spline or external spline root circle RC12 with the external spline secondary diameter DM12. However, the external spline root circle RC12 can have a different diameter than the external spline secondary diameter DM12. The external spline secondary diameter DM12 is equal to or less than 32 mm. The external spline secondary diameter DM12 is equal to or less than 31 mm. The external spline secondary diameter DM12 is equal to or greater than 28 mm. In this embodiment, the external spline secondary diameter DM12 is 30.2 mm. However, the external spline secondary diameter DM12 is not limited to this embodiment and the aforementioned ranges.

[0193] The larger-diameter part 42 comprises an outer diameter DM13 that is larger than the external spline main diameter DM11. The outer diameter DM13 ranges from 32 mm to 40 mm. In this embodiment, the outer diameter DM13 is 35 mm. However, the outer diameter DM13 is not limited to this embodiment.

[0194] As in Fig. As shown in Figure 25, the multiple external splined drive surfaces 48 each comprise a radial length RL11, defined from the radially outermost edge 48A to the radially innermost edge 48B. The sum of the radial lengths RL11 of the multiple external splined drive surfaces 48 is equal to or greater than 7 mm. The sum of the radial lengths RL11 is equal to or greater than 10 mm. The sum of the radial lengths RL11 is equal to or greater than 15 mm. The sum of the radial lengths RL11 is equal to or less than 36 mm. In this embodiment, the sum of the radial lengths RL11 is 16.6 mm. However, the sum of the radial lengths RL11 is not limited to this embodiment.

[0195] The multiple external spline teeth 40 have an additional radial length RL12. The additional radial lengths RL12 are each defined from the external spline root circle RC12 to the radially outermost ends 40A of the multiple external spline teeth 40. The sum of the additional radial lengths RL12 is equal to or greater than 20 mm. In this embodiment, the sum of the additional radial lengths RL12 is 31.2 mm. However, the sum of the additional radial lengths RL12 is not limited to this embodiment.

[0196] At least one of the at least ten external spline teeth 40 is circumferentially symmetrical with respect to a reference line CL1. The reference line CL1 extends radially with respect to the rotational center axis A1 from the rotational center axis A1 to a circumferential center CP1 of a radially outermost end 40A of the at least one of the at least ten external spline teeth 40. However, at least one of the external spline teeth 40 may have an asymmetrical shape with respect to the reference line CL1. The at least one of the at least ten external spline teeth 40 has the external spline drive surface 48 and the external spline non-drive surface 50.

[0197] At least one surface of the multiple external spline drive surfaces 48 has a first external spline surface angle AG11. The first external spline surface angle AG11 is defined between the external spline drive surface 48 and a first radial line L11. The first radial line L11 extends from the rotation center axis A1 of the rear bicycle hub assembly 12 to the radially outermost edge 48A of the external spline drive surface 48. The first outer helix angle PA11 or the second outer helix angle PA12 is defined between the adjacent first radial lines L11 (see, for example, Fig. 23) defined.

[0198] At least one of the external spline non-drive surfaces 50 comprises a second external spline surface angle AG12. The second external spline surface angle AG12 is defined between the external spline non-drive surface 50 and a second radial line L12. The second radial line L12 extends from the rotation center axis A1 of the rear bicycle hub assembly 12 to the radially outermost edge 50A of the external spline non-drive surface 50.

[0199] In this embodiment, the second external spline surface angle AG12 is equal to the first external spline surface angle AGI 1. However, the first external spline surface angle AG11 can be different from the second external spline surface angle AG12.

[0200] The first external spline surface angle AG11 is equal to or less than 6 degrees. The first external spline surface angle AG11 is equal to or greater than 0 degrees. The second external spline surface angle AG12 is equal to or less than 6 degrees. The second external spline surface angle AG12 is equal to or greater than 0 degrees. In this embodiment, the first external spline surface angle AG11 is 5 degrees. The second external spline surface angle AG12 is 5 degrees. However, the first external spline surface angle AG11 and the second external spline surface angle AG12 are not limited to this embodiment and the preceding areas.

[0201] As in Fig. 27 and Fig. As can be seen in Figure 28, the brake rotor support body 34 includes at least one additional external splined tooth 52, which is arranged to engage with the bicycle brake rotor 16 ( Fig. 1) engages. In this embodiment, the brake rotor support body 34 comprises an additional base carrier 54 and several additional external splined teeth 52. The additional base carrier 54 has a tubular shape and extends from the hub body 36 along the axis of rotation A1. The additional external splined teeth 52 extend radially outward from the additional base carrier 54. The total number of additional external splined teeth 52 is 52. However, the total number of additional external splined teeth 52 is not limited to this embodiment.

[0202] As in Fig. As can be seen in Figure 28, the at least one additional external spline tooth 52 includes an additional external spline main diameter DM14. As shown in Fig. As can be seen in Figure 29, the additional external spline main diameter DM14 is larger than the external spline main diameter DM11. The additional external spline main diameter DM14 is essentially equal to the outer diameter DM13 of the larger-diameter part 42. However, the additional external spline main diameter DM14 may be equal to or smaller than the external spline main diameter DM11. The additional external spline main diameter DM14 may differ from the outer diameter DM13 of the larger-diameter part 42.

[0203] As in Fig. As shown in Figure 29, the hub body 36 comprises a first spoke attachment section 36A and a second spoke attachment section 36B. Several first spokes SK1 are connected to the first spoke attachment section 36A. Several second spokes SK2 are connected to the second spoke attachment section 36B. In this embodiment, the first spoke attachment section 36A comprises several first attachment holes 36A1. The first spoke SK1 extends through the first attachment hole 36A1. The second spoke attachment section 36B comprises several second attachment holes 36B1. The second spoke SK2 extends through the second attachment hole 36B1. The term "spoke attachment section," as used herein, includes configurations in which the spoke attachment opening has a flange-like shape, such that, as shown in Figure 29, the spoke attachment opening is connected to the first spoke attachment section 36A. Fig. 29 shows the spoke attachment section extending radially outwards with respect to the axis of rotation of the rear bicycle hub assembly, and configurations in which the spoke attachment section is an opening formed directly on a radially outer circumferential surface of the hub body.

[0204] The second spoke fastening section 36B is spaced axially D2 apart from the first spoke fastening section 36A. The first spoke fastening section 36A is positioned axially D2 between the sprocket support body 28 and the second spoke fastening section 36B. The second spoke fastening section 36B is positioned axially D2 between the first spoke fastening section 36A and the brake rotor support body 34.

[0205] The first spoke fastening section 36A has a first axially outermost part 36C. The second spoke fastening section 36B has a second axially outermost part 36D. The first axially outermost part 36C comprises a surface that faces in the axial direction D2 towards the first frame BF1 in a state in which the rear bicycle hub assembly 12 is attached to the bicycle frame BF. The second axially outermost part 36D comprises a surface that faces in the axial direction D2 towards the second frame BF2 in a state in which the rear bicycle hub assembly 12 is attached to the bicycle frame BF.

[0206] The hub body 36 comprises a first axial length AL1. The first axial length AL1 is defined in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle chainring assembly 14 between the first axially outermost part 36C of the first spoke attachment section 36A and the second axially outermost part 36D of the second spoke attachment section 36B. The first axial length AL1 may be equal to or greater than 55 mm. The first axial length AL1 may be equal to or greater than 60 mm. The first axial length AL1 may be equal to or greater than 65 mm. In this embodiment, the first axial length AL1 may be 67 mm. However, the first axial length AL1 is not limited to this embodiment and the preceding ranges. Examples of the first axial length AL1 include 55.7 mm, 62.3 mm, and 67 mm.

[0207] As in Fig. As shown in Figure 29, the hub axle 30 comprises a first axial frame contact surface 30B1 and a second axial frame contact surface 30C1. The first axial frame contact surface 30B1 is configured to bear against a first part BF12 of the bicycle frame BF in the axial direction D2 with respect to the pivot axis A1 of the rear bicycle sprocket assembly 14 when the rear bicycle hub assembly 12 is attached to the bicycle frame BF. The second axial frame contact surface 30C1 is configured to bear against a second part BF22 of the bicycle frame BF in the axial direction D2 when the rear bicycle hub assembly 12 is attached to the bicycle frame BF. The first axial frame contact surface 30B1 is positioned closer to the sprocket support body 28 in the axial direction D2 than the second axial frame contact surface 30C1.The sprocket support body 28 is provided in the axial direction D2 between the first axial frame contact surface 30B1 and the second axial frame contact surface 30C1.

[0208] The hub axle 30 comprises a second axial length AL2, defined in the axial direction D2 between the first axial frame contact surface 30B1 and the second axial frame contact surface 30C1. The second axial length AL2 can be equal to or greater than 140 mm. The second axial length AL2 can be equal to or greater than 145 mm. The second axial length AL2 can be equal to or greater than 147 mm. The second axial length AL2 can be 148 mm. However, the second axial length AL2 is not limited to this embodiment and the preceding ranges. Examples of the second axial length AL2 include 142 mm, 148 mm, and 157 mm.

[0209] The ratio of the first axial length AL1 to the second axial length AL2 can be equal to or greater than 0.3. The ratio of the first axial length AL1 to the second axial length AL2 can be equal to or greater than 0.4. The ratio of the first axial length AL1 to the second axial length AL2 can be equal to or less than 0.5. For example, the ratio of the first axial length AL1 (67 mm) to the second axial length AL2 (148 mm) is approximately 0.45. However, the ratio of the first axial length AL1 to the second axial length AL2 is not limited to this embodiment and the preceding ranges. Examples of the ratio of the first axial length AL1 to the second axial length AL2 include approximately 0.42 (AL1 is 62.3 mm and AL2 is 148 mm) or approximately 0.39 (AL1 is 55.7 mm and AL2 is 142 mm).

[0210] As in Fig. As shown in Figure 6, the sprocket support body 28 comprises a first axial end 28B, a second axial end 28C, and an axial sprocket contact surface 28D. The second axial end 28C is opposite the first axial end 28B in the axial direction D2. The axial median plane CPL bisects the second axial length AL2 in the axial direction D2. The axial sprocket contact surface 28D is positioned closer to the axial median plane CPL of the rear bicycle hub assembly 12 in the axial direction D2 than the first axial end 28B. The second axial end 28C is positioned closer to the axial median plane CPL of the rear bicycle hub assembly 12 in the axial direction D2 than the axial sprocket contact surface 28D. In this embodiment, the axial sprocket contact surface 28D is provided on the part 42 with the larger diameter, whereas the axial sprocket contact surface 28D can be provided on other parts of the rear bicycle hub assembly 12 as required.The axial sprocket contact surface 28D is in contact with the rear bicycle sprocket assembly 14 in a state in which the rear bicycle sprocket assembly 14 is attached to the sprocket bearing body 28. The axial sprocket contact surface 28D faces the first axial end 28B in the axial direction D2.

[0211] As in Fig. As shown in Figure 6, an axial length AL3 of a sprocket assembly is defined in the axial direction D2 between the first axial frame contact surface 30B1 and the axial sprocket contact surface 28D of the sprocket bearing body 28. In this embodiment, the sprocket assembly axial length AL3 is in the range of 35 mm to 45 mm. For example, the axial length AL3 of the sprocket assembly is 39.64 mm. The sprocket assembly axial length AL3 can also be extended to, for example, 44.25 mm by omitting the larger diameter part 42. However, the sprocket assembly axial length AL3 is not limited to this embodiment and the range described above.

[0212] The larger-diameter part 42 has an axial end 42A located furthest from the first axial frame contact surface 30B1 in the axial direction D2. An additional axial length AL4 is defined in the axial direction D2 from the first axial frame contact surface 30B1 to the axial end 42A. The additional axial length AL4 ranges from 38 mm to 47 mm. The additional axial length AL4 can range from 44 mm to 45 mm. The additional axial length AL4 can also be in the range of 40 mm to 41 mm. In this embodiment, the additional axial length AL4 is 44.25 mm. However, the additional axial length AL4 is not limited to this embodiment and the aforementioned ranges.

[0213] An axial length AL5 of the larger-diameter part 42 is in the range of 3 mm to 6 mm. In this embodiment, the axial length AL5 with the larger diameter is 4.61 mm. However, the axial length AL5 of the larger-diameter part 42 is not limited to this embodiment and the aforementioned ranges.

[0214] The ratio of the first axial length AL1 to the sprocket assembly axial length AL3 is in the range of 1.2 to 1.7. For example, the ratio of the first axial length AL1 to the sprocket assembly axial length AL3 is 1.4 if the first axial length AL1 is 55.7 mm and the sprocket assembly axial length AL3 is 39.64 mm. However, the ratio of the first axial length AL1 to the sprocket assembly axial length AL3 is not limited to this embodiment and the range described above. For example, the ratio of the first axial length AL1 to the sprocket assembly axial length AL3 can be 1.57 if the first axial length AL1 is 62.3 mm and the sprocket assembly axial length AL3 is 39.64 mm, or the ratio of the first axial length AL1 to the sprocket assembly axial length AL3 can be 1.69 if the first axial length AL1 is 67 mm and the sprocket assembly axial length AL3 is 39.64 mm.

[0215] As in Fig. As shown in Figure 30, the sprocket support element 37 comprises a hub engagement part 60 and several support arms 62. The several support arms 62 extend radially outwards from the hub engagement part 60. The support arm 62 comprises a first to eighth fastening part 62A to 62H. The several spacers 38 comprise several first spacers 38A, several second spacers 38B, several third spacers 38C, several fourth spacers 38D, several fifth spacers 38E, several sixth spacers 38F, and several seventh spacers 38G.

[0216] As in Fig. As shown in Figure 6, the first spacers 38A are located between the additional sprockets SP5 and SP6. The second spacers 38B are located between the additional sprockets SP6 and SP7. The third spacers 38C are located between the additional sprockets SP7 and SP8. The fourth spacers 38D are located between the additional sprockets SP8 and SP9. The fifth spacers 38E are located between the additional sprockets SP9 and SP10. The sixth spacers 38F are located between the additional sprockets SP10 and SP11. The seventh spacers 38G are located between the additional sprockets SP11 and SP12.

[0217] The additional sprocket SP6 and the first spacer 38A are attached to the first mounting part 62A with adhesive 37A. The additional sprocket SP7 and the second spacer 38B are attached to the second mounting part 62B with adhesive 37A. The additional sprocket SP8 and the third spacer 38C are attached to the third mounting part 62C with adhesive 37A. The additional sprocket SP9 and the fourth spacer 38D are attached to the fourth mounting part 62D with adhesive 37A. The additional sprocket SP10 and the fifth spacer 38E are attached to the fifth mounting part 62E with adhesive 37A. The additional sprocket SP11 and the sixth spacer 38F are attached to the sixth mounting part 62F with adhesive 37A. The additional sprocket SP12 and the seventh spacer 38G are attached to the seventh mounting part 62G with the adhesive 37A.The additional sprocket SP5 and the second ring 39B are attached to the eighth mounting part 62H with the adhesive 37A. The hub engagement part 60, the sprockets SP1 to SP4, the first ring 39A and the second ring 39B are held in the axial direction D2 between the larger diameter part 42 and the radial projection 32C of the locking element 32.

[0218] In this embodiment, each of the sprockets SP1 to SP12 is made of a metallic material such as aluminum, iron, or titanium. The sprocket support element 37 is made of a non-metallic resin material. Each of the first to seventh spacers 38A and 38G, the first ring 39A, and the second ring 39B are made of a non-metallic material, such as a resin. However, at least one of the sprockets SP1 to SP12 may be made at least partially of a non-metallic material. At least one of the sprocket support element 37, the first to seventh spacers 38A and 38G, the first ring 39A, and the second ring 39B may be made at least partially of a metallic material, such as aluminum, iron, or titanium.

[0219] As in Fig. As shown in Figure 7, the first sprocket SP1 includes a first opening SP1K. The first opening SP1K includes a first minimum diameter MD1. As shown in Fig. As shown in Figure 31, the tubular body 32A of the locking element 32 extends through the first opening SP1K of the first sprocket SP1 in the state in which the rear bicycle sprocket assembly 14 is attached to the sprocket support body 28. The first opening SP1K of the first sprocket SP1 is configured such that the first axial end 32D of the tubular body 32A of the locking element 32 passes through the first opening SP1K of the first sprocket SP1 in the state in which the rear bicycle sprocket assembly 14 is attached to the sprocket support body 28. The first axial end 28B of the sprocket support body 28 is spaced apart from the first opening SP1K of the first sprocket SP1 without extending through the first opening SP1K. The first minimum diameter MD1 is smaller than a minimum outer diameter MD28 of the sprocket support body 28 of the rear bicycle hub assembly 12.In this embodiment, the minimum outer diameter MD28 is equal to the secondary diameter of the external splined gear DM12 (. Fig. 26) the several external splined teeth 40 of the sprocket support body 28.

[0220] As in Fig. As shown in Figure 31, the tubular body 32A has a first outer diameter ED1 that is equal to or less than 27 mm. The first outer diameter ED1 is equal to or greater than 26 mm. The radial projection 32C has a second outer diameter ED2 that is equal to or less than 32 mm. The second outer diameter ED2 is equal to or greater than 30 mm. In this embodiment, the first outer diameter ED1 is 26.2 mm. The second outer diameter ED2 is 30.8 mm. However, at least one of the first outer diameter ED1 and the second outer diameter ED2 is not limited to this embodiment and the aforementioned areas.

[0221] The radial projection 32C comprises an axial width ED3, which is defined in the axial direction D2. For example, the axial width ED3 of the radial projection 32C is 2 mm. However, the axial width ED3 is not limited to this embodiment.

[0222] The locking element 32 comprises an axial length ED4, defined from the radial projection 32C to the first axial end 32D in the axial direction D2. The axial length ED4 of the locking element 32 is 10 mm. However, the axial length ED4 is not limited to this embodiment.

[0223] As in Fig. As can be seen in Figure 8, the first sprocket SP2 has a first opening SP2K. The multiple first sprockets SP1 and SP2 each include the first opening. The first opening SP2K has a first minimum diameter MD2. As shown in Fig. As shown in Figure 31, the tubular body 32A of the locking element 32 extends through the first opening SP2K of the first sprocket SP2 in the state in which the rear bicycle sprocket assembly 14 is attached to the sprocket support body 28. The first axial end 28B of the sprocket support body 28 is spaced from the first opening SP2K of the first sprocket SP2 without extending through the first opening SP2K. The first minimum diameter MD2 is smaller than the minimum outer diameter MD28 of the sprocket support body 28 of the rear bicycle hub assembly 12.

[0224] As in Fig. As shown in Figure 9, the second sprocket SP3 includes a second opening SP3K. The second opening SP3K includes a second minimum diameter MD3. As shown in Figure 9, the second sprocket SP3 SP3K includes a second opening SP3K. The second opening SP3K includes a second minimum diameter MD3. As shown in Figure 9, the second sprocket SP3K includes a second opening SP3K. The second opening SP3K includes a second minimum diameter MD3. Fig. As shown in Figure 31, the tubular body 32A of the locking element 32 and the sprocket support body 28 extend through the second opening SP3K of the second sprocket SP3 in the state in which the rear bicycle sprocket assembly 14 is attached to the sprocket support body 28. The end 28B of the sprocket support body 28 is located in the axial direction D2 between the second opening SP3K and the first opening SP1K. The first axial end 28B of the sprocket support body 28 is located in the axial direction D2 between the second opening SP3K and the first opening SP2K. The second minimum diameter MD3 is equal to or greater than the minimum outer diameter MD28 of the sprocket support body 28 of the rear bicycle hub assembly 12.

[0225] As in Fig. As can be seen in Figure 10, the second sprocket SP4 includes a second opening SP4K. That is, the multiple second sprockets SP3 and SP4 each include the second opening. The second opening SP4K includes a second minimum diameter MD4. As shown in Figure 10, the second sprocket SP4 SP4 includes a second opening SP4K. Fig. As shown in Figure 31, the sprocket support body 28 extends through the second opening SP4K of the second sprocket SP4 in the state in which the rear sprocket assembly 14 is attached to the sprocket support body 28. The first axial end 28B of the sprocket support body 28 is located in the axial direction D2 between the second opening SP4K and the first opening SP1K. The second minimum diameter MD4 is equal to or greater than the minimum outer diameter MD28 of the sprocket support body 28 of the rear bicycle hub assembly 12.

[0226] As in Fig. As shown in Figure 32, the first sprocket SP2 comprises at least ten internal splined teeth 63, which are configured to engage with the sprocket support body 28 of the rear bicycle hub assembly 12. The at least ten internal splined teeth 63 are provided at the first opening SP2K. The at least ten internal splined teeth 63 are provided as a first torque transmission structure of the first sprocket SP2, as will be described later.

[0227] The total number of the at least ten internal sprocket teeth 63 of the first sprocket SP2 is equal to or greater than 20. The total number of the at least ten internal sprocket teeth 63 of the first sprocket SP2 is equal to or greater than 28. The total number of internal sprocket teeth 63 is equal to or less than 72. In this embodiment, the total number of internal sprocket teeth 63 is equal to 29. However, the total number of internal sprocket teeth 63 is not limited to this embodiment and the preceding areas.

[0228] As in Fig. As shown in Figure 9, the second sprocket SP3 comprises at least ten internal splined teeth 64, which are configured to engage with the sprocket support body 28 of the rear bicycle hub assembly 12. In this embodiment, the at least ten internal splined teeth 64 of the second sprocket SP3 define the second minimum diameter MD3 as a secondary internal splined diameter of the at least ten internal splined teeth 64.

[0229] The total number of the at least ten internal sprocket teeth 64 of the second sprocket SP3 is equal to or greater than 20. The total number of the at least ten internal sprocket teeth 64 of the second sprocket SP3 is equal to or greater than 29. The total number of internal sprocket teeth 64 is equal to or less than 72. In this embodiment, the total number of internal sprocket teeth 64 is equal to 29. However, the total number of internal sprocket teeth 64 is not limited to this embodiment and the aforementioned areas.

[0230] As in Fig. As shown in Figure 10, the second sprocket SP4 comprises at least ten internal splined teeth 65, which are configured to engage with the sprocket support body 28 of the rear bicycle hub assembly. The multiple second sprockets SP3 and SP4 each comprise the internal splined teeth of the rear bicycle hub assembly 12. In this embodiment, at least one of the internal splined teeth 65 of the second sprocket SP4 defines the second minimum diameter MD4 as a secondary internal splined diameter of the at least ten internal splined teeth 65.

[0231] The total number of the at least ten internal sprocket teeth 65 of the second sprocket SP4 is equal to or greater than 20. The total number of the at least ten internal sprocket teeth 65 of the second sprocket SP4 is equal to or greater than 28. The total number of internal sprocket teeth 65 is equal to or less than 72. In this embodiment, the total number of internal sprocket teeth 65 is equal to 29. However, the total number of internal sprocket teeth 65 is not limited to this embodiment and the aforementioned areas.

[0232] As in Fig. As shown in Figure 33, the at least ten internal sprocket teeth 64 of the second sprocket SP3 have a first internal pitch angle PA21 and a second internal pitch angle PA22. At least two internal sprocket teeth of the at least ten internal sprocket teeth 64 of the second sprocket SP3 are arranged circumferentially at the first internal sprocket angle PA21 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14. The at least two internal sprocket teeth of the at least ten internal sprocket teeth 64 are adjacent to each other circumferentially D1 without any further sprocket teeth between them. In other words, at least two of the multiple internal sprocket teeth 64 are arranged circumferentially around the first internal sprocket angle PA21 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14.At least two further internal sprocket teeth of the at least ten internal sprocket teeth 64 of the second sprocket SP3 are arranged circumferentially at the second inner helix angle PA22 with respect to the axis of rotation A1. The at least two other internal sprocket teeth of the at least ten internal sprocket teeth 64 of the second sprocket SP3 are adjacent to each other circumferentially D1 without any other sprocket tooth in between. In other words, at least two of the multiple internal sprocket teeth 64 of the second sprocket SP3 are arranged circumferentially at the second inner helix angle PA22 with respect to the axis of rotation A1. In this embodiment, the second inner helix angle PA22 differs from the first inner helix angle PA21. However, the second inner helix angle PA22 can be substantially the same as the first inner helix angle PA21.

[0233] In this embodiment, the internal spline teeth 64 are arranged circumferentially at the first inner helix angle PA21 in the circumferential direction D1. Two internal spline teeth of the internal spline teeth 64 are arranged at the second inner helix angle PA22 in the circumferential direction D1. However, at least two internal spline teeth of the internal spline teeth 64 can be arranged at a different inner helix angle in the circumferential direction D1.

[0234] The first internal slope angle PA21 is in the range of 5 degrees to 36 degrees. The first internal slope angle PA21 is in the range of 10 degrees to 20 degrees. The first internal slope angle PA21 is equal to or less than 15 degrees. In this embodiment, the first internal slope angle PA21 is, for example, 12 degrees. However, the first internal slope angle PA21 is not limited to this embodiment and the aforementioned ranges.

[0235] The second internal slope angle PA22 lies in the range of 5 degrees to 36 degrees. In this embodiment, the second internal slope angle PA22 is 24 degrees. However, the second internal slope angle PA22 is not limited to this embodiment and the aforementioned range.

[0236] At least one of the at least ten internal sprocket teeth 64 of the second sprocket SP3 has a first sprocket tooth form that differs from a second sprocket tooth form of any other of the at least ten internal sprocket teeth 64. At least one of the at least ten internal sprocket teeth 64 of the second sprocket SP3 has a first sprocket tooth size that differs from a second sprocket tooth size of any other of the at least ten internal sprocket teeth 64. At least one of the at least ten internal sprocket teeth 64 has a cross-sectional shape that differs from a cross-sectional shape of any other of the at least ten internal sprocket teeth 64. As in Fig. As can be seen in 34, the internal wedge teeth 64 can, however, have the same shape. The at least ten internal wedge teeth 64 can have the same size. The at least ten internal wedge teeth 64 can have the same cross-sectional shape.

[0237] As in Fig. As can be seen in Figure 35, at least one of the at least ten internal spline teeth 64 has an internal spline drive surface 66. The at least one of the at least ten internal spline teeth 64 has an internal spline non-drive surface 68. The at least ten internal spline teeth 64 have several internal spline drive surfaces 66 in order to transmit the drive torque F1 from the rear bicycle hub assembly 12 during pedal actuation. Fig. 6) to be included. The at least ten internal splined teeth 64 have several internal splined non-drive surfaces 68. The internal splined drive surface 66 can be brought into contact with the sprocket support body 28 to transmit the drive torque F1 from the sprocket SP1 to the sprocket support body 28 when the pedal is actuated. The internal splined drive surface 66 faces the direction of drive rotation D11. The internal splined drive surface 66 faces the external splined drive surface 48 of the rear bicycle hub assembly 12 in a state in which the rear bicycle chain assembly 14 is attached to the rear bicycle hub assembly 12. The internal splined non-drive surface 68 is provided on the rear side of the internal splined drive surface 66 in the circumferential direction D1.The internal splined non-drive surface 68 is oriented in the reverse direction of rotation D12 in order to prevent the drive torque F1 from being transmitted from the sprocket SP1 to the sprocket support body 28 during pedal actuation. The internal splined non-drive surface 68 faces the external splined non-drive surface 50 of the rear bicycle hub assembly 12 in a state in which the rear bicycle chain assembly 14 is attached to the rear bicycle hub assembly 12.

[0238] The at least ten internal spline teeth 64 each have a maximum circumferential width MW2. The maximum circumferential width MW2 is defined as the maximum width to accommodate a compressive force F3 applied to the internal spline tooth 64. The maximum circumferential width MW2 is defined as a straight distance based on the internal spline drive surface 66.

[0239] The multiple internal splined drive surfaces 66 each comprise a radially outermost edge 66A and a radially innermost edge 66B. A second reference circle RC21 is defined at the radially outermost edge 66A and is centered on the rotational center axis A1. The second reference circle RC21 intersects the internal splined non-drive surface 68 at a reference point 68R. The maximum circumferential width MW2 extends directly from the radially innermost edge 66B to the reference point 68R in the circumferential direction D1.

[0240] The non-drive surface of the internal spline has a radially outermost edge 68A and a radially innermost edge 68B. The non-drive surface of the internal spline extends from the radially outermost edge 68A to the radially innermost edge 68B. The reference point 68R is located between the radially outermost edge 68A and the radially innermost edge 68B.

[0241] The sum of the maximum circumferential widths MW2 is equal to or greater than 40 mm. The sum of the maximum circumferential widths MW2 can be equal to or greater than 45 mm. The sum of the maximum circumferential widths MW2 can be equal to or greater than 50 mm. In this embodiment, the sum of the maximum circumferential widths MW2 is 50.8 mm. However, the sum of the maximum circumferential widths MW2 is not limited to this embodiment.

[0242] As in Fig. As shown in Figure 36, the at least ten internal sprocket teeth 64 of the second sprocket SP3 have an internal sprocket main diameter DM21. The at least one internal sprocket tooth 64 of the second sprocket SP3 comprises an internal sprocket root circle RC22 with the internal sprocket main diameter DM21. The internal sprocket main diameter DM21 is equal to or less than 34 mm. The internal sprocket main diameter DM21 of the second sprocket SP3 is equal to or less than 33 mm. The internal sprocket main diameter DM21 of the second sprocket SP3 is equal to or greater than 29 mm. In this embodiment, the internal sprocket main diameter DM21 of the second sprocket SP3 is 32.8 mm. However, the internal sprocket main diameter DM21 of the second sprocket SP3 is not limited to this embodiment and the preceding ranges.

[0243] The at least ten internal sprocket teeth 64 of the second sprocket SP3 comprise an internal sprocket secondary diameter DM22 that is equal to or less than 32 mm. The internal sprocket secondary diameter DM22 is equal to or less than 31 mm. The internal sprocket secondary diameter DM22 is equal to or greater than 28 mm. In this embodiment, the internal sprocket secondary diameter DM22 is 30.4 mm. However, the internal sprocket secondary diameter DM22 is not limited to this embodiment and the aforementioned ranges.

[0244] As in Fig. As shown in Figure 18, the additional sprocket SP12 includes a maximum tooth tip diameter TD12. The maximum tooth tip diameter TD12 is a maximum outer diameter defined by the multiple sprocket teeth SP12B. A ratio of the internal spline main diameter DM21 ( Fig. 36) to the largest tooth tip diameter TD12 lies in the range of 0.15 to 0.18. In this embodiment, the ratio of the internal spline main diameter DM21 to the largest tooth tip diameter TD12 is equal to 0.15. However, the ratio of the internal spline main diameter DM21 to the largest tooth tip diameter TD12 is not limited to this embodiment and the aforementioned ranges.

[0245] As in Fig. As shown in Figure 35, the multiple internal spline drive surfaces 66 have a radially outermost edge 66A and a radially innermost edge 66B. Each of the multiple internal spline drive surfaces 66 has a radial length RL21, defined from the radially outermost edge 66A to the radially innermost edge 66B. The sum of the radial lengths RL21 of the multiple internal spline drive surfaces 66 is equal to or greater than 7 mm. The sum of the radial lengths RL21 is equal to or greater than 10 mm. The sum of the radial lengths RL21 is equal to or greater than 15 mm. The sum of the radial lengths RL21 is equal to or less than 36 mm. In this embodiment, the sum of the radial lengths RL21 is 16.6 mm. However, the sum of the radial lengths RL21 is not limited to this embodiment and the aforementioned areas.

[0246] The multiple internal spline teeth 64 have an additional radial length RL22. The additional radial lengths RL22 are each defined from the internal spline root circle RC22 to the radially innermost ends 64A of the multiple internal spline teeth 64. The sum of the additional radial lengths RL22 is equal to or greater than 12 mm. In this embodiment, the sum of the additional radial lengths RL22 is 34.8 mm. However, the sum of the additional radial lengths RL22 is not limited to this embodiment and the aforementioned areas.

[0247] At least one of the at least ten internal sprocket teeth 64 of the second sprocket SP3 is circumferentially symmetrical with respect to a reference line CL2. The reference line CL2 extends from the axis of rotation A1 to a circumferential center CP2 of a radially innermost end 64A of the at least one of the at least ten internal sprocket teeth 64 in a radial direction with respect to the axis of rotation A1. However, at least one of the internal sprocket teeth 64 may have an asymmetrical shape with respect to the reference line CL2. The at least one of the internal sprocket teeth 64 comprises the internal spline drive surface 66 and the internal spline non-drive surface 68.

[0248] The internal splined drive surface 66 has a first internal splined surface angle AG21. The first internal splined surface angle AG21 is defined between the internal splined drive surface 66 and a first radial line L21. The first radial line L21 extends from the rotational center axis A1 of the rear bicycle sprocket assembly 14 to the radially outermost edge 66A of the internal splined drive surface 66. The first internal helix angle PA21 or the second internal helix angle PA22 is between the adjacent first radial lines L21 (see e.g. Fig. 33) defined.

[0249] The internal splined non-drive surface 68 has a second internal splined surface angle AG22. The second internal splined surface angle AG22 is defined between the internal splined non-drive surface 68 and a second radial line L22. The second radial line L22 extends from the rotational center axis A1 of the rear bicycle sprocket assembly 14 to the radially outermost edge 68A of the internal splined non-drive surface 68.

[0250] In this embodiment, the second internal spline surface angle AG22 is the same as the first internal spline surface angle AG21. However, the first internal spline surface angle AG21 may differ from the second internal spline surface angle AG22.

[0251] The first internal spline angle AG21 lies in the range of 0 degrees to 6 degrees. The second internal spline angle AG22 lies in the range of 0 degrees to 6 degrees. In this embodiment, the first internal spline angle AG21 is 5 degrees. The second internal spline angle AG22 is 5 degrees. However, the first internal spline angle AG21 and the second internal spline angle AG22 are not limited to this embodiment and the aforementioned ranges.

[0252] As in Fig. As shown in Figure 37, the inner splined teeth 64 mesh with the outer splined teeth 40 to transmit the drive torque F1 from the second sprocket SP3 to the sprocket support body 28. The inner splined drive surface 66 can be brought into contact with the inner splined drive surface 48 to transmit the drive torque F1 from the second sprocket SP3 to the sprocket support body 28. The inner splined non-drive surface 68 is spaced from the outer splined non-drive surface 50 in a state in which the inner splined drive surface 66 is in contact with the outer splined drive surface 48.

[0253] The internal sprocket teeth 63 of the first sprocket SP2 and the internal sprocket teeth 65 of the second sprocket SP4 essentially have the same structure as the internal sprocket teeth 64 of the second sprocket SP3. Therefore, for the sake of brevity, they are not described in detail here.

[0254] As in Fig. As shown in Figure 2, the sprocket support element 37 comprises at least ten internal splined teeth 76, which are configured to engage with the sprocket support body 28 of the rear bicycle hub assembly 12. The multiple internal splined teeth 76 have essentially the same structure as the multiple internal splined teeth 64. Therefore, for the sake of brevity, they are not described in detail here.

[0255] As in Fig. As shown in Figure 38, the first sprocket SP1 comprises a first torque transmission structure SP1T, which is provided on the first inwardly facing side SP1H to transmit a pedal actuation torque directly or indirectly to the sprocket support body 28. In this embodiment, the first torque transmission structure SP1T comprises several first torque transmission teeth SP1T1 for indirectly transmitting a pedal actuation torque to the sprocket support body 28. The first torque transmission structure SP1T comprises at least ten first torque transmission teeth SP1T1. Preferably, the total number of the at least ten first torque transmission teeth SP1T1 is equal to or greater than 20. Even more preferably, the total number of the at least ten first torque transmission teeth SP1T1 is equal to or greater than 28. In this embodiment, the total number of the at least ten first torque transmission teeth SP1T1 is 29.However, the total number of at least ten first torque transmission teeth SP1T1 is not limited to this embodiment and the foregoing areas.

[0256] As in Fig. 38 and Fig. As shown in Figure 39, the first sprocket SP2 comprises a first inwardly facing side SP2H and a first outwardly facing side SP2G. The first outwardly facing side SP2G is arranged in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket assembly 14 opposite the first inwardly facing side SP2H. The first sprocket SP2 comprises a first torque transmission structure SP2M, which is provided on the first inwardly facing side SP2H to transmit a pedal torque directly or indirectly to the sprocket support body 28. In this embodiment, the internal splined tooth 63 of the first sprocket SP2 can also be referred to as a first torque transmission tooth 63. The first torque transmission structure SP2M comprises the multiple first torque transmission teeth 63 to transmit a pedal torque directly to the sprocket support body 28.The first torque transmission structure SP2M comprises at least ten first torque transmission teeth 63. The total number of the at least ten first torque transmission teeth 63 is equal to or greater than 20. More preferably, the total number of the at least ten first torque transmission teeth 63 is equal to or greater than 28. In this embodiment, the total number of the at least ten first torque transmission teeth 63 is 29. However, the total number of the at least ten first torque transmission teeth 63 is not limited to this embodiment and the foregoing. The first torque-transmitting tooth 63 can also be referred to as the internal spline tooth 63.

[0257] As in Fig. As shown in Figure 39, the first sprocket SP2 comprises a second torque transmission structure SP2T to receive pedal torque from the first sprocket SP1. The second torque transmission structure SP2T is provided on the first outward-facing side SP2G. In this embodiment, the second torque transmission structure SP2T comprises several second torque transmission teeth SP2T1. Preferably, the total number of second torque transmission teeth SP2T1 is equal to or greater than 20. More preferably, the total number of second torque transmission teeth SP2T1 is equal to or greater than 28. In this embodiment, the total number of second torque transmission teeth SP2T1 is 29. However, the total number of second torque transmission teeth SP2T1 is not limited to this embodiment and the preceding sections. The first torque transmission structure SP1T engages with the second torque transmission structure SP2T.The multiple first torque transmission teeth SP1T1 mesh with the multiple second torque transmission teeth SP2T1 to transmit the drive torque F1.

[0258] As in Fig. 23 and Fig. As shown in Figure 24, the sprocket support body 28 includes a hub indicator 28I, which is provided at an axial end of the base carrier 41. When viewed along the axis of rotation A1, the hub indicator 28I is located in a region of the second outer helix angle PA12. In this embodiment, the hub indicator 28I comprises a point. However, the hub indicator 28I can also comprise other shapes, such as a triangle or a line. Furthermore, the hub indicator 28I can be a separate element that is attached to the sprocket support body 28, for example, by a bonding structure such as an adhesive. The position of the hub indicator 28I is not limited to this embodiment.

[0259] As in Fig. As shown in Figure 7, the first sprocket SP1 includes a sprocket indicator SP1I, which is provided at an axial end of the sprocket body SP1A. In this embodiment, the sprocket indicator SP1I comprises a dot. However, the sprocket indicator SP1I can also comprise other shapes, such as a triangle and a line. Furthermore, the sprocket indicator SP1I can be a separate element that is attached to the sprocket SP1, e.g., with a bonding structure such as an adhesive. The position of the sprocket indicator SP1I is not limited to this embodiment. The sprocket indicator SP1I can be provided on any of the other sprockets SP2 to SP12. The sprocket indicator SP1I can also be provided on the sprocket support element 37.

[0260] As in Fig. As can be seen in Figure 6, the rear bicycle hub assembly 12 further comprises a freewheel structure 78. The chainring support body 28 is operatively connected to the hub body 36 via the freewheel structure 78. The freewheel structure 78 is designed to connect the chainring support body 28 to the hub body 36 in order to rotate the chainring support body 28 together with the hub body 36 in the drive direction D11 during pedaling. Fig. 5) to rotate. The freewheel structure 78 is designed to allow the chain wheel support body 28 to rotate in the reverse direction of rotation D12 relative to the hub body 36 during coasting ( Fig. 5) rotates. Accordingly, the freewheel structure 78 can be described as a one-way coupling structure 78. The freewheel structure 78 will be described in detail later.

[0261] The rear bicycle hub assembly 12 comprises a first bearing 79A and a second bearing 79B. The first bearing 79A and the second bearing 79B are provided between the sprocket support body 28 and the hub axle 30 in order to rotatably support the sprocket support body 28 with respect to the hub axle 30 about the pivot axis A1.

[0262] In this embodiment, the sprocket support body 28, the brake rotor support body 34, and the hub body 36 are all made of a metallic material, such as aluminum, iron, or titanium. However, at least one of the sprocket support body 28, the brake rotor support body 34, and the hub body 36 may be made of a non-metallic material.

[0263] As in Fig. As shown in Figure 40, the freewheel structure 78 comprises a first ratchet element 80 and a second ratchet element 82. The first ratchet element 80 is configured to engage with one of the hub body 36 and the sprocket support body 28 in a torque-transmitting manner. The second ratchet element 82 is configured to engage with the other of the hub body 36 and the sprocket support body 28 in a torque-transmitting manner. In this embodiment, the first ratchet element 80 engages with the sprocket support body 28 in a torque-transmitting manner. The second ratchet element 82 engages with the hub body 36 in a torque-transmitting manner. However, the first pawl element 80 can be configured to engage with the hub body 36 in a torque-transmitting manner.The second pawl element 82 can be configured to engage with the sprocket support body 28 in a torque-transmitting manner.

[0264] The first pawl element 80 is attached to the sprocket support body 28 so that it rotates together with the sprocket support body 28 about the central axis of rotation A1 relative to the hub body 36. The second pawl element 82 is attached to the hub body 36 so that it rotates together with the hub body 36 about the central axis of rotation A1 relative to the sprocket support body 28. Each of the first pawl element 80 and the second pawl element 82 has an annular shape.

[0265] At least one of the first pawl element 80 and the second pawl element 82 is movable in the axial direction D2 with respect to the hub axis 30 and the axis of rotation A1. In this embodiment, both the first pawl element 80 and the second pawl element 82 are movable in the axial direction D2 with respect to the hub axis 30. The second pawl element 82 is movable in the axial direction D2 with respect to the hub body 36. The first pawl element 80 is movable in the axial direction D2 with respect to the sprocket support body 28.

[0266] The hub body 36 comprises a freewheel housing 36H with an annular shape. The freewheel housing 36H extends in the axial direction D2. The first pawl element 80 and the second pawl element 82 are provided in a fixed position within the freewheel housing 36H.

[0267] As in Fig. As shown in Figure 41, the first pawl element 80 comprises at least one first detent or pawl tooth 80A. In this embodiment, the at least one first pawl tooth 80A comprises several first pawl teeth 80A. The several first pawl teeth 80A are arranged in the circumferential direction D1 to provide a wedge-shaped toothing.

[0268] As in Fig. As shown in Figure 42, the second pawl element 82 comprises at least one second detent or pawl tooth 82A, which is configured to engage with the at least one first pawl tooth 80A in a torque-transmitting manner. The at least one second pawl tooth 82A engages with the at least one first pawl tooth 80A to transmit the rotational force F1 from the sprocket support body 28 to the hub body 36 ( Fig. 40) to transmit. In this embodiment, the at least one second pawl tooth 82A comprises several second pawl teeth 82A which are configured to engage with the several first pawl teeth 80A in a torque-transmitting manner. The several second pawl teeth 82A are arranged in the circumferential direction D1 to provide a splined connection. The several second pawl teeth 82A can be brought into engagement with the several first pawl teeth 80A. The first pawl element 80 and the second pawl element 82 rotate together in a state in which the second pawl teeth 82A are engaged with the first pawl teeth 80A.

[0269] As in Fig. 41 and Fig. As shown in Figure 42, the sprocket support body 28 comprises an outer circumferential surface 28P with a first helical splined section 28H. The first pawl element 80 is configured to engage with the sprocket support body 28 in a torque-transmitting manner and comprises a second helical splined section 80H that meshes with the first helical splined section 28H. The first pawl element 80 is movably mounted in the axial direction D2 with respect to the sprocket support body 28 via the second helical splined section 80H, which meshes with the first helical splined section 28H, during drive by a first thrust force applied by the sprocket support body 28. In this embodiment, the first helical splined section 28H comprises the multiple helical outer splined teeth 46.The second helical spline 80H comprises several helical internal spline teeth 80H1 that mesh with the several helical external spline teeth 46.

[0270] As in Fig. As shown in Figure 43, the hub body 36 comprises an inner circumferential surface 36S and at least one first tooth 36T. The at least one first tooth 36T is provided on the inner circumferential surface 36S. In this embodiment, the freewheel housing 36H comprises the inner circumferential surface 36S. The hub body 36 comprises several first teeth 36T. The several first teeth 36T are provided on the inner circumferential surface 36S and extend radially inward from the inner circumferential surface 36S with respect to the axis of rotation A1. The first teeth 36T are arranged in the circumferential direction D1 to define several recesses 36R between adjacent two teeth of the first teeth 36T.

[0271] The second pawl element 82 comprises a hub body engagement section 82E, which engages with the hub body 36 in a torque-transmitting manner to transmit the rotational force F1 from the first pawl element 80 via the hub body engagement section 82E to the hub body 36. One of the hub body engagement section 82E and the hub body 36 comprises at least one radially extending projection. The other of the hub body engagement section 82E and the hub body 36 comprises at least one recess that engages with the at least one projection. In this embodiment, the hub body engagement section 82E comprises at least one radially extending projection 82T. The hub body 36 comprises at least one recess 36R that engages with the at least one projection 82T. In this embodiment, the hub body engagement section 82E comprises several projections 82T.The multiple projections 82T engage with the multiple recesses 36R.

[0272] As in Fig. As can be seen in Figure 42, the outer circumferential surface 28P of the sprocket support body 28 has a guide section 28G which is designed to guide the first pawl element 80 to the hub body 36 during rolling. The guide section 28G is arranged such that it forms an obtuse angle AG28 ( Fig. 48) defined by the first helical splined section 28H. The sprocket support body 28 comprises several guide sections 28G. The guide section 28G is designed to guide the first pawl element 80 towards the hub body 36 during coasting or freewheeling. The guide section 28G guides the first pawl element 80 towards the hub body 36 to engage the at least one first pawl tooth 80A ( Fig. 41) and the at least one second pawl tooth 82A. The guide section 28G is configured to move the first pawl element 80 away from the second pawl element 82 in the axial direction D2. The guide section 28G extends at least in the circumferential direction D1 with respect to the sprocket support body 28. The guide section 28G extends from one tooth of the multiple helical external spline teeth 46 in at least the circumferential direction D1. While the guide section 28G is integrally formed with the helical external spline tooth 46 as a single, unified element in this embodiment, the guide section 28G can be a separate element from the multiple helical external spline teeth 46.The first pawl element 80 and the second pawl element 82 are uniformly separated from each other during rolling due to the guide section 28G, particularly in a case where the guide section 28G is arranged such that it defines an obtuse angle AG 28 with respect to the first helical tooth 28H. This also leads to a reduction in noise during rolling because the at least one first pawl tooth 80A and the at least one second pawl tooth 82A are gently separated from each other during rolling.

[0273] As in Fig. As shown in Figure 40, the rear bicycle hub assembly 12 further comprises a preload element 84. The preload element 84 is arranged between the hub body 36 and the first pawl element 80 in order to preload the first pawl element 80 in the axial direction D2 towards the second pawl element 82. In this embodiment, the preload element 84 is, for example, a compression spring.

[0274] As in Fig. As can be seen in Figure 44, the preload element 84 is compressed in the axial direction D2 between the hub body 36 and the first pawl element 80. The preload element 84 preloads the first pawl element 80 towards the second pawl element 82 in order to maintain an engagement state in which the first pawl element 80 and the second pawl element 82 are engaged with each other via the first pawl teeth 80A and the second pawl teeth 82A.

[0275] Preferably, the preload element 84 engages with the hub body 36 in order to rotate with the hub body 36. The preload element 84 is attached to the hub body 36 in order to rotate together with the hub body 36 about the axis of rotation A1 ( Fig. 40) to rotate. The preload element 84 comprises a wound body 84A and a connecting end 84B. The hub body 36 has a connecting hole 36F. The connecting end 84B is provided in the connecting hole 36F, so that the preload element 84, together with the hub body 36, rotates about the axis of rotation A1 ( Fig. 40) turns around.

[0276] As in Fig. As shown in Figure 44, the outer circumferential surface 28P of the sprocket support body 28 supports the first pawl element 80 and the second pawl element 82. The first pawl element 80 comprises an axially oriented surface 80S that is directed in the axial direction D2. The at least one first pawl tooth 80A is arranged on the axially oriented surface 80S of the first pawl element 80. In this embodiment, the multiple first pawl teeth 80A are arranged on the axially oriented surface 80S of the first pawl element 80. The axially oriented surface 80S is substantially perpendicular to the axial direction D2. However, the axially oriented surface 80S does not have to be perpendicular to the axial direction D2.

[0277] The second latch element 82 comprises an axially oriented surface 82S, which is directed in the axial direction D2. The at least one second latch tooth 82A is arranged on the axially oriented surface 82S of the second latch element 82. The axially oriented surface 82S of the second latch element 82 faces the axially oriented surface 80S of the first latch element 80. In this embodiment, the multiple second latch teeth 82A are arranged on the axially oriented surface 82S of the second latch element 82. The axially oriented surface 82S is substantially perpendicular to the axial direction D2. However, the axially oriented surface 82S does not necessarily have to be perpendicular to the axial direction D2.

[0278] As in Fig. As shown in Figure 40, the rear bicycle hub assembly 12 comprises a spacer 86, a support element 88, a sliding element 90, an additional preload element 92, and a receiving element 94. However, it is possible to omit at least one of the spacer element 86, the support element 88, the sliding element 90, the additional preload element 92, and the receiving element 94 from the rear bicycle hub assembly 12.

[0279] As in Fig. 44 and Fig. As shown in Figure 45, the spacer 86 is provided at least partially between the at least one first tooth 36T and the at least one projection 82T in the circumferential direction D1 defined around the axis of rotation A1. In this embodiment, the spacer 86 is provided partially between the first teeth 36T and the projections 82T in the circumferential direction D1. However, the spacer 86 can be provided completely between the first teeth 36T and the projections 82T in the circumferential direction D1.

[0280] As in Fig. As shown in Figures 45 to 47, the spacer 86 comprises at least one intermediate section 86A, which is provided between the at least one first tooth 36T and the at least one projection 82T. The at least one intermediate section 86A is provided between the at least one first tooth 36T and the at least one projection 82T in the circumferential direction D1. In this embodiment, the spacer 86 comprises several intermediate sections 86A, each provided between the first teeth 36T and the projections 82T in the circumferential direction D1. While the spacer 86 in this embodiment has the intermediate sections 86A, the spacer 86 can also comprise a single intermediate section 86A.

[0281] As in Fig. 46 and Fig. As shown in Figure 47, the spacer 86 comprises a connecting section 86B. The several intermediate sections 86A extend from the connecting section 86B in the axial direction D2 parallel to the axis of rotation A1. While the spacer 86 in this embodiment comprises the connecting section 86B, the connecting section 86B can be omitted from the spacer 86.

[0282] The spacer 86 comprises a non-metallic material. In this embodiment, the non-metallic material comprises a resin material. Examples of the resin material include synthetic resin. The non-metallic material can comprise a material other than the resin material instead of, or in addition to, the resin material. While in this embodiment the intermediate sections 86A and the connecting section 86B are integrally formed as a single, one-piece element, at least one of the intermediate sections 86A can be a section separate from the connecting section 86B.

[0283] As in Fig. 44 and Fig. As can be seen in Figure 45, the several intermediate sections 86A are provided between the inner circumferential surface 36S of the hub body 36 and an outer circumferential surface 82P of the second pawl element 82 in the radial direction.

[0284] As in Fig. As shown in Figure 44, the support element 88 is provided in the axial direction D2 between the hub body 36 and the second pawl element 82. The support element 88 is attached to the second pawl element 82. The support element 88 extends radially outwards from the first pawl element 80. The support element 88 can be brought into contact with the first pawl element 80. The support element 88 preferably comprises a non-metallic material. The support element 88, which is made of a non-metallic material, reduces the noise during operation of the rear bicycle hub assembly 12. In this embodiment, the non-metallic material comprises a resin. The non-metallic material can comprise a different material instead of, or in addition to, the resin.

[0285] The sliding element 90 is arranged in the axial direction D2 parallel to the axis of rotation A1 between the sprocket support body 28 and the second pawl element 82. The second pawl element 82 is arranged in the axial direction D2 between the first pawl element 80 and the sliding element 90. The sliding element 90 is preferably made of a non-metallic material. The sliding element 90, which is made of a non-metallic material, reduces the noise during operation of the rear bicycle hub assembly 12. In this embodiment, the non-metallic material comprises a resin. The non-metallic material can comprise a material other than the resin, either instead of or in addition to the resin.

[0286] The sprocket support body 28 includes a stop 28E to hold the second pawl element 82 in place, thus limiting axial movement of the second pawl element 82 away from the hub body 36. In this embodiment, the stop 28E can hold the second pawl element 82 in place via the sliding element 90. Alternatively, the stop 28E can hold the second pawl element 82 in place directly. The first pawl element 80 is arranged on an axial side of the second pawl element 82 that faces the stop 28E of the sprocket support body 28 in the axial direction D2. The sliding element 90 is provided in the axial direction D2 between the stop 28E of the sprocket support body 28 and the second pawl element 82.

[0287] As in Fig. As shown in Figure 44, the additional preloading element 92 is provided in the axial direction D2 between the hub body 36 and the second pawl element 82 in order to preload the second pawl element 82 towards the sprocket support body 28. In this embodiment, the additional preloading element 92 preloads the second pawl element 82 in the axial direction D2 via the support element 88. The additional preloading element 92 is provided radially outside the preloading element 84. In this embodiment, the additional preloading element 92 is provided radially outside the multiple second pawl teeth 82A.

[0288] The receiving element 94 comprises a non-metallic material. The receiving element 94, which is made of a non-metallic material, prevents the preloading element 84 from being over-preloaded during operation of the rear hub assembly 12. In this embodiment, the non-metallic material comprises a resin. The non-metallic material can be a different material than the resin. The receiving element 94 comprises an axially receiving part 96 and a radially receiving part 98. The axially receiving part 96 is positioned in the axial direction D2 between the first pawl element 80 and the preloading element 84. The radially receiving part 98 extends from the axially receiving part 96 in the axial direction D2. The radially receiving part 98 is positioned radially inward from the preloading element 84.The axially receiving part 96 and the radially receiving part 98 are designed as a single, one-piece unit. However, the axially receiving part 96 can be a separate element from the radially receiving part 98.

[0289] As in Fig. As shown in Figure 44, the rear hub assembly 12 includes a sealing structure 100. The sealing structure 100 is located between the sprocket support body 28 and the hub body 36. The hub body 36 has an interior space 102. Each of the sprocket support body 28, the preload element 84, the first pawl element 80, and the second pawl element 82 are at least partially located within the interior space 102 of the hub body 36. The interior space 102 is sealed by the sealing structure 100. In this embodiment, no lubricant is provided within the interior space 102. However, the rear hub assembly 12 may include a lubricant provided within the interior space 102. Any gap between the elements located within the interior space 102 can be reduced compared to a case where the rear hub assembly 12 includes a lubricant provided within the interior space 102 when no lubricant is provided.

[0290] The operation of the rear bicycle hub assembly is described in the Fig. 44, Fig. 48 and Fig. 49 described.

[0291] As in Fig. As shown in Figure 44, the axial direction D2 encompasses a first axial direction D21 and, opposite to the first axial direction D21, a second axial direction D22. A preload force F5 is exerted by the preload element 84 on the receiving element 94 in the first axial direction D21. The preload force F5 of the preload element 84 preloads the receiving element 94, the first pawl element 80, the second pawl element 82, and the sliding element 90 towards the sprocket support body 28 in the first axial direction D21. This brings the first wedge teeth 80A into engagement with the second pawl teeth 82A.

[0292] As in Fig. As can be seen in Figure 48, when a pedal torque T1 is applied to the sprocket support body 28 in the drive direction D11, the helical splined teeth 80H1 are guided by the helical splined teeth 46 relative to the sprocket support body 28 in the first axial direction D21. This brings the first splined teeth 80A into strong engagement with the second pawl teeth 82A. In this state, the pedal torque T1 is transmitted from the sprocket support body 28 to the hub body 36 ( Fig. 44) via the first latch element 80 and the second latch element 82 ( Fig. 44) transferred.

[0293] As in Fig. As can be seen in Figure 48, the first pawl element 80 is in contact with the guide section 28G in order to engage the second pawl element 82 during rolling with a rotational friction force F6, which is located between the preload element 84 ( Fig. 44) and the first latch element 80 is generated, to avoid interference. As in Fig. As can be seen in figure 49, a freewheel torque T2 is applied to the hub body 36 in the direction of rotation D11 during coasting. The freewheel torque T2 is transmitted by the hub body 36 ( Fig. 44) via the second jack element 82 ( Fig. 44) to the first pawl element 80. At this time, the helical inner splined teeth 80H1 are guided by the helical outer splined teeth 46 relative to the sprocket support body 28 in the second axial direction D22. This moves the first pawl element 80 relative to the sprocket support body 28 in the second axial direction D22 against the preload force F5. Thus, the first pawl element 80 is moved away from the second pawl element 82 in the second axial direction D22, thereby weakening the engagement between the first pawl teeth 80A and the second pawl teeth 82A. This allows the second pawl element 82 to rotate relative to the first pawl element 80 in the drive direction D11, thus preventing the idle torque T2 from being transmitted from the hub body 36 via the first pawl element 80 and the second pawl element 82 to the sprocket support body 28.At this point, the first clutch teeth 80A slide with the second clutch teeth 82A in the circumferential direction D1. Modifications

[0294] As in Fig. As can be seen in the preceding embodiments and other modifications, the external splined tooth 40 may have a groove 40G, which is provided in the circumferential direction D1 between the external splined tooth drive surface 48 and the external splined tooth non-drive surface 50. The groove 40G reduces the weight of the rear bicycle hub assembly 12.

[0295] As in Fig. As can be seen in Figure 51, in the foregoing modifications and other modifications, the internal splined tooth 64 may have a groove 64G, which is provided between the internal splined tooth drive surface 66 and the internal splined tooth non-drive surface 68 in the circumferential direction D1. The groove 64G reduces the weight of the rear bicycle sprocket assembly 14.

[0296] In the present application, at least ten internal sprocket teeth can be provided indirectly at a second opening of a second sprocket, whereas in the preceding embodiments, at least ten internal sprocket teeth are provided directly at the second opening of each of the second sprockets SP3 and SP4. For example, instead of providing at least ten internal sprocket teeth directly at the second opening of the second sprocket SP3 and / or the second sprocket SP4, at least one of the second sprockets SP3 and SP4 can be attached to a sprocket support element with at least ten internal sprocket teeth. Alternatively, instead of at least ten internal sprocket teeth at a second opening of a second sprocket, at least one second sprocket can be formed in one piece with at least one additional sprocket having at least ten internal sprocket teeth as a single, unified element.Since such a second sprocket indirectly has at least ten internal sprocket teeth via a sprocket support element and / or an additional sprocket, this also means that the second sprocket has at least ten internal sprocket teeth that are arranged to engage with a sprocket support body of a bicycle hub unit.

[0297] The rear bicycle chainring assembly 14 can comprise only one first chainring or more than two first chainrings, whereas in the foregoing embodiments the rear bicycle chainring assembly 14 comprises two first chainrings SP1 and SP2.

[0298] The rear bicycle chainring assembly 14 can comprise only one second chainring or more than two second chainrings, whereas in the foregoing embodiments the rear bicycle chainring assembly 14 comprises two second chainrings SP3 and SP4.

[0299] As in Fig. As shown in Figure 52, the total number of at least ten external splined teeth 40 in the sprocket support body 28 can range from 22 to 24. For example, the total number of at least ten external splined teeth 40 can be 23. The first external helix angle PA11 can range from 13 degrees to 17 degrees. For example, the first external helix angle PA11 can be 15 degrees. The second external helix angle PA12 can range from 28 degrees to 32 degrees. For example, the second external helix angle PA12 can be 30 degrees. The first external helix angle PA11 is half the second external helix angle PA12. However, the first external helix angle PA11 can differ from half the second external helix angle PA12. The total number of at least ten external splined teeth 40 is not limited to the modifications and ranges described above.The first external slope angle PA11 is not limited to the modifications and ranges described above. The second external slope angle PA12 is not limited to the modifications and ranges described above.

[0300] As in Fig. As can be seen in Figure 53, the sum of the radial lengths RL11 of the multiple external splined drive surfaces 48 in the sprocket support body 28 can range from 11 mm to 14 mm. The sum of the radial lengths RL11 of the multiple external splined drive surfaces 48 can be 12.5 mm. The sum of the additional radial lengths RL12 can be between 26 mm and 30 mm. For example, the sum of the additional radial lengths RL12 can be 28.2 mm. However, the sum of the additional radial lengths RL12 is not limited to the modifications and ranges described above.

[0301] As in Fig. As can be seen in Figure 54, the total number of at least ten first torque transmission teeth (SP1T1) in the first torque transmission structure (SP1T) of the first sprocket (SP1) can range from 22 to 24. For example, the total number of at least ten first torque transmission teeth (SP1T1) can be 23. However, the total number of at least ten first torque transmission teeth (SP1T1) is not limited to the modification and range described above.

[0302] As in Fig.As can be seen in Figure 55, in the second torque transmission structure SP2T of the first sprocket SP2, the total number of at least ten second torque transmission teeth SP2T1 can range from 22 to 24. For example, the total number of at least ten second torque transmission teeth SP2T1 can be 23. However, the total number of at least ten second torque transmission teeth SP2T1 is not limited to the modification and range described above.

[0303] As in Fig. As can be seen in Figure 56, the total number of at least ten internal sprocket teeth 63 of the first sprocket SP2 can be in the range of 22 to 24. For example, the total number of at least ten internal sprocket teeth 63 of the first sprocket SP2 can be 23. However, the total number of at least ten internal sprocket teeth 63 is not limited to the above modification and range.

[0304] As in Fig. As can be seen in Figure 57, the total number of at least ten internal sprocket teeth 64 of the second sprocket SP3 can range from 22 to 24. For example, the total number of at least ten internal sprocket teeth 64 of the second sprocket SP3 can be 23. However, the total number of at least ten internal sprocket teeth 64 is not limited to the above modification and range.

[0305] As in Fig. As can be seen in Figure 58, the total number of at least ten internal sprocket teeth 65 of the second sprocket SP4 can range from 22 to 24. For example, the total number of at least ten internal sprocket teeth 65 of the second sprocket SP4 can be 23. However, the total number of at least ten internal sprocket teeth 65 is not limited to the above modification and range.

[0306] As in Fig. As can be seen in Figure 59, the first inner helix angle PA21 in the at least ten inner sprocket teeth 64 of the second sprocket SP3 can be in the range of 13 degrees to 17 degrees. The first inner helix angle PA21 can, for example, be 15 degrees. The second inner helix angle PA22 can be between 28 degrees and 32 degrees. The second inner helix angle PA22 can, for example, be 30 degrees. The first inner helix angle PA21 can be half the second inner helix angle PA22. However, the first inner helix angle PA21 can deviate from half the second inner helix angle PA22. The first inner helix angle PA21 is not limited to the above modification and range. The second inner helix angle PA22 is not limited to the above modification and range.

[0307] As in Fig. As can be seen in Figure 60, the sum of the radial lengths RL21 of the multiple internal splined drive surfaces 66 in the internal splined teeth 64 of the second sprocket SP3 can range from 11 mm to 14 mm. For example, the sum of the radial lengths RL21 of the multiple internal splined drive surfaces 66 can be 12.5 mm. However, the sum of the radial lengths RL21 is not limited to the above modification and the above range. The sum of the additional radial lengths RL22 can range from 26 mm to 29 mm. For example, the sum of the additional radial lengths RL22 is 27.6 mm. However, the sum of the additional radial lengths RL22 is not limited to this embodiment and the above ranges. The internal sprocket teeth 63 of the first sprocket SP2 and the internal sprocket teeth 65 of the second sprocket SP4 comprise the same structures as the internal sprocket teeth 64 of the second sprocket SP3.

[0308] As in Fig. As can be seen in Figure 61, the internal sprocket teeth 76 of the sprocket support element 37 can have the same structures as the internal sprocket teeth 64 of the second sprocket SP3, which are shown in the Fig. 57, Fig. 59 and Fig. Figure 60 shows the total number of at least ten internal spline teeth 76 of the sprocket support element 37, which can range from 22 to 24. For example, the total number of at least ten internal spline teeth 76 of the sprocket support element 37 can be 23. However, the total number of at least ten internal spline teeth 76 is not limited to the above modification and range. The structure of the internal spline teeth 64, which are shown in Fig. The formula shown in Figure 60 can be applied to the internal splined teeth 76 of the sprocket support element 37.

[0309] As in Fig. As shown in Figure 62, the rear bicycle sprocket assembly 14 can include an additional sprocket SP13. The additional sprocket SP13 is connected to the additional sprocket SP12 by several coupling elements SP13R. The additional sprocket SP13 comprises a sprocket body SP13A and at least one sprocket tooth SP13B. The sprocket body SP13A of the additional sprocket SP13 is connected to the sprocket body SP12A of the additional sprocket SP12 by the several coupling elements SP13R. The at least one sprocket tooth SP13B extends radially outward from the sprocket body SP13A. The total number of at least one sprocket tooth SP13B is greater than the total number of at least one sprocket tooth SP12B. Preferably, the total number of teeth of the at least one sprocket tooth SP13B is equal to or greater than 46. More preferably, the total number of teeth of the at least one sprocket tooth SP13B is equal to or greater than 50.The total number of teeth of the at least one sprocket tooth SP13B is, for example, 54.

[0310] The tooth profile of the sprocket teeth SP1B to SP13B of the sprockets SP1 to SP13 can have a conventional tooth profile and / or a narrow / wide tooth profile. In particular, the sprocket teeth SP1B to SP13B of the sprockets SP1 to SP13, as a narrow / wide tooth profile, can also have at least one first tooth with a first axial maximum chain engagement width and at least one second tooth with a second axial maximum chain engagement width that is smaller than the first axial maximum chain engagement width. The first axial maximum chain engagement width and the second axial maximum chain engagement width are measured along the axial direction D2.The first axial maximum chain engagement width is larger than an axial inner engagement space defined by a pair of inner engagement plates of the bicycle chain 20, and smaller than an axial outer engagement space defined by a pair of outer engagement plates of the bicycle chain 20, the pair of outer engagement plates facing each other in the axial direction D2 when the bicycle chain 20 is engaged with one of the sprockets SP1B to SP13B. The second axial maximum chain engagement width is smaller than the axial inner engagement space defined by the pair of inner engagement plates of the bicycle chain 20.Accordingly, the at least one first tooth is configured to engage with a pair of outer connecting plates of the bicycle chain 20, wherein the pair of outer connecting plates faces each other in the axial direction D2 when the bicycle chain 20 is engaged with one of the sprockets SP1B to SP13B, and the at least one second tooth is configured to engage with a pair of inner connecting plates of the bicycle chain 20, wherein the pair of inner connecting plates faces each other in the axial direction D2. Preferably, the at least one first tooth and the at least one second tooth are arranged alternately on an outer circumference of at least one of the sprockets SP1B to SP13B.Preferably, the sprocket teeth SP1B to SP13B of the sprockets SP1 to SP13 comprise several first teeth, each having the aforementioned first maximum chain engagement width, and several second teeth, each having the aforementioned second maximum chain engagement width. Preferably, the several first teeth and the several second teeth are arranged alternately on an outer circumference of at least one of the sprockets SP1B to SP13B. Preferably, the sprocket teeth of a largest sprocket can have such a narrow / wide tooth profile. Accordingly, it is preferable that the sprocket teeth SP12B of the sprocket SP12 in . Fig. 6 or the sprocket teeth SP13B of the sprocket SP13 in Fig. 62 have at least one first tooth with the aforementioned first axial maximum chain engagement width and at least one second tooth with the aforementioned second axial maximum chain engagement width.

[0311] The term "comprehensive" and its derivatives, as used herein, are to be understood as open terms that specify the presence of the mentioned features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unmentioned features, elements, components, groups, integers, and / or steps. This concept also applies to words with similar meanings, such as the terms "with," "exhibit," and their derivatives.

[0312] The terms “link”, “section”, “part”, “element”, “body” and “structure”, when used in the singular, can have the dual meaning of a single part or multiple parts.

[0313] The ordinal numbers, such as "first" and "second," as used in the present application, are merely identifiers and do not have any other meaning, such as indicating a specific order or the like. Furthermore, the term "first element," for example, does not imply the existence of a "second element," and the term "second element" does not imply the existence of a "first element."

[0314] The term “pair of”, as used herein, may include the configuration in which the pair of elements have different shapes or structures from each other, in addition to the configuration in which the pair of elements have the same shapes or structures.

[0315] The expressions “a”, “one or more” and “at least one” can be used interchangeably herein.

[0316] Finally, the terms of extent, such as "essentially," "by," and "approximately," as used herein, signify a reasonable degree of deviation from the modified term, such that the final result is not significantly altered. All numerical values ​​described in this application may be interpreted as encompassing "essentially," "by," and "approximately."

[0317] Obviously, many modifications and variations of the present invention are possible in light of the teaching described above. It is therefore understood that the invention can be implemented differently within the scope of protection of the attached claims than specifically described here.

Claims

[1] Rear bicycle chainring assembly designed to be attached to a chainring support body of a rear bicycle hub assembly, the rear bicycle chainring assembly comprising: several bicycle chainrings, including: a first sprocket, featuring: a first opening with a first minimum diameter that is smaller than a minimum outer diameter of the sprocket support body of the rear bicycle hub assembly; and a second sprocket, having: a second opening having a second minimum diameter that is equal to or greater than the minimum outer diameter of the sprocket support body of the rear bicycle hub assembly; and at least ten internal splined teeth designed to engage with the sprocket support body of the rear bicycle hub assembly, wherein at least one of the at least ten internal sprocket teeth of the second sprocket is symmetrical in the circumferential direction with respect to a reference line extending from the axis of rotation to a circumferential center of a radially outermost end of the at least one of the at least ten internal sprocket teeth in a radial direction with respect to the axis of rotation. which have at least ten internal splined teeth, several internal splined drive surfaces, each comprising several internal splined drive surfaces: a radial outermost edge, a radial innermost edge, and a radial length defined from the radially outermost edge to the radially innermost edge, and a sum of the radial lengths of the multiple internal splined drive surfaces equal to or greater than 7 mm, and wherein at least one of the at least ten internal wedge teeth includes: an internal spline drive surface with a first internal spline surface angle defined between the internal spline drive surface and a first radial line extending from a rotational center axis of the rear bicycle chainring assembly to a radially outermost edge of the internal spline drive surface, and the first internal spline surface angle lies in the range of 0 degrees to 6 degrees. [2] Rear bicycle chainring assembly according to claim 1, wherein the first internal splined surface angle is 5 degrees. [3] Rear bicycle chainring assembly according to claim 1, wherein the at least one of the at least ten internal splined teeth comprises: an internal splined non-drive surface with a second internal splined surface angle defined between the internal splined non-drive surface and a second radial line extending from the rotational center axis of the rear bicycle sprocket assembly to a radially outermost edge of the internal splined non-drive surface, and the second internal spline surface angle lies in the range of 0 degrees to 6 degrees. [4] Rear bicycle chainring assembly according to claim 3, wherein the second internal splined surface angle is 5 degrees. [5] Rear bicycle chainring assembly according to any one of claims 1 to 4, wherein the at least ten internal splined teeth have an internal splined main diameter equal to or less than 34 mm. [6] Rear bicycle chainring assembly according to claim 5, wherein the internal splined main diameter is equal to or less than 33 mm. [7] Rear bicycle chainring assembly according to claim 5, wherein the internal splined main diameter is equal to or greater than 29 mm. [8] Rear bicycle chainring assembly according to any one of claims 1 to 6, wherein the at least ten internal splined teeth have an internal splined tooth secondary diameter equal to or less than 32 mm. [9] Rear bicycle chainring assembly according to any one of claims 1 to 6, wherein the internal splined secondary diameter is equal to or less than 31 mm. [10] Rear bicycle chainring assembly according to any one of claims 1 to 7, wherein the internal splined secondary diameter is equal to or greater than 28 mm.

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