Rear bicycle chainring assembly

Abstract

Rear bicycle chainring assembly (10; 210; 310), designed to be mounted to a chainring support section (4) of a rear bicycle hub assembly (1), the rear bicycle chainring assembly (10; 210; 310) comprising: a first sprocket (SP11; 12; 212; 312), a second sprocket (SP10; 38) and a locking link (26; 226; 326), wherein the first sprocket (SP11; 12; 212; 312) includes: a first bicycle-inward directed surface (14); a first bicycle-outward directed surface (16), opposite to the first bicycle-inward directed surface (14) in an axial direction (Da), parallel to a rotation center axis (Ax) of the rear bicycle chainring assembly (10; 210; 310); a first opening (24) having a first diameter (D1) that is smaller than a radial outer diameter (D0) of the sprocket support section (4) of the rear bicycle hub assembly (1); and A first torque transmission structure (18) provided on the first bicycle-inward facing surface (14) and configured to transmit a pedal torque to the second sprocket (SP10; 38), adjacent to the first sprocket (SP11; 12; 212; 312), without a further sprocket between the first sprocket (SP11; 12; 212; 312) and the second sprocket (SP10; 38) in the axial direction (Da), preferably the first torque transmission structure (18) includes a plurality of first splines (18s); and wherein the locking element (26; 226; 326) includes: comprising a main body (28) having a first axial end (28fe) configured to pass through the first opening (24) of the first sprocket (SP11; 12; 212; 312), and a second axial end (28re) opposite the first axial end (28fe) in the axial direction (Da), wherein the first axial end (28fe) is positioned closer to an axial centerline (CL) of the rear bicycle hub assembly (1) than the second axial end (28re), in a state in which the rear bicycle sprocket assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1); an external threaded section (30) provided at the first axial end (28fe), wherein the external threaded section (30) is configured to engage with an internal threaded section (4t) of the rear bicycle hub assembly (1) in the state in which the rear bicycle chainring assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1); and a radial projection (32) which extends radially outwards from the second axial end (28re) with respect to the axis of rotation (Ax) in order to limit an axial displacement of the first sprocket (SP11; 12; 212; 312) with respect to the sprocket support section (4) of the rear bicycle hub assembly (1) in the state in which the rear bicycle sprocket assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1).

Description

BACKGROUND OF THE INVENTION Cross-reference to related applications

[0001] This application claims priority over U.S. patent application no. 15 / 195,969, filed on June 28, 2016. The entire disclosure of U.S. patent application no. 15 / 195,969 is hereby fully incorporated by reference herein. Field of invention

[0002] The present invention relates to a rear bicycle chainring assembly. Background discussion

[0003] Cycling is becoming an increasingly popular form of recreation as well as a means of transportation. Furthermore, cycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation, or competition, the bicycle industry has constantly improved various bicycle components. One bicycle component that has been extensively redesigned is the rear chainring assembly.

[0004] US 8,641,151 B2 discloses a sprocket carrier structure comprising a main body, a plurality of projections, and a bearing ring. The main body has an outer surface with a plurality of parallel sprocket mounting grooves that define a plurality of sprocket engagement grooves between the sprocket mounting grooves. The projections extend radially outward with respect to an axis of rotation of the main body than the sprocket mounting grooves. Each of the projections has a first surface that points in a first axial direction of the main body.

[0005] US Patent 2017 / 0021667A1 discloses an improved hub sharpener comprising a hub body, a freewheel assembly, a connecting sleeve, and an external freewheel. The connecting sleeve is linked to the ratchet sleeve of the hub body to provide more space for the external freewheel. The design of the connecting sleeve and external freewheel allows the hub body, which incorporates several smaller freewheels, to offer a higher pedaling speed for a descending bicycle. When descending, the smaller sprockets of the external freewheel help the rider maintain an optimal pedaling speed on steep terrain, and the bicycle's speed can be easily controlled.

[0006] US 7,931,553 B2 discloses a bicycle sprocket device comprising a sprocket mounting element, a first sprocket, and a second sprocket. The sprocket mounting element includes a hub mounting section and a sprocket mounting section, the hub mounting section being designed to be attached to a rotating hub that rotates about an axis of rotation. The sprocket mounting section includes a first sprocket mounting surface facing in a first direction and a second sprocket mounting surface facing in an opposite second direction. The first sprocket is mounted on the first sprocket mounting surface, and the second sprocket is mounted on the second sprocket mounting surface.

[0007] US 6 428 437 B1 discloses a power transmission element with an improved drive sprocket arrangement comprising at least one preformed sprocket and a central sprocket carrier, wherein the sprocket teeth of the sprocket extend beyond the central sprocket carrier to match a roller chain, and wherein the sprocket is attached to the sprocket carrier by deformation of the sprocket carrier. SUMMARY OF THE INVENTION

[0008] According to a first aspect of the present invention, a rear bicycle sprocket assembly is configured to be mounted on a sprocket support section of a rear bicycle hub assembly. The rear bicycle sprocket assembly comprises a first sprocket and a locking element. The first sprocket includes a first bicycle-inward facing surface, a first bicycle-outward facing surface, a first opening, and a first torque transmission structure. The first bicycle-outward facing surface is axially opposite to the first bicycle-inward facing surface, parallel to a rotational center axis of the rear bicycle sprocket assembly. The first opening has a first diameter that is smaller than a radial outer diameter of the sprocket support section of the rear bicycle hub assembly.The first torque transmission structure is provided on the first bicycle-inward facing surface and is configured to transmit pedal torque to a second chainring adjacent to the first chainring, without any further chainring between the first and second chainrings in the axial direction. The locking element comprises a main body, an externally threaded section, and a radial projection. The main body has a first axial end configured to pass through the first opening of the first chainring and a second axial end opposite the first axial end. The first axial end is positioned closer to an axial centerline of the rear bicycle hub assembly than the second axial end when the rear bicycle chainring assembly is / is mounted to the rear bicycle hub assembly. The externally threaded section is provided at the first axial end.The external threaded section is designed to engage with an internal threaded section of the rear bicycle hub assembly when the rear bicycle chainring assembly is mounted 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 limit axial displacement of the first chainring relative to the chainring support member of the rear bicycle hub assembly when the rear bicycle chainring assembly is mounted to the rear bicycle hub assembly.

[0009] With the rear sprocket arrangement described in the first aspect, it is possible to mount the first sprocket, which is a radially small sprocket with fewer than or equal to ten teeth, to the rear hub assembly with the locking link. Accordingly, a bicycle fitted with this rear sprocket arrangement can have a wide gear ratio range.

[0010] Preferably, the first torque transmission structure includes a multitude of first splines.

[0011] Consequently, it is possible to reliably transfer the pedal torque from the first sprocket to the second sprocket.

[0012] Preferably, the main body of the locking element has a second diameter that is equal to or smaller than the first diameter of the first opening of the first sprocket.

[0013] Consequently, it is possible to mount the first sprocket, which has a radially small number of teeth (less than ten), to the rear bicycle hub assembly with the locking link. Accordingly, a bicycle with this rear sprocket assembly can have a wide gear ratio range.

[0014] Preferably, the radial projection is positioned further away from the axial centerline of the rear bicycle hub assembly than the first bicycle-inward directed surface of the first chainring, in the state in which the rear bicycle chainring assembly is / is mounted to the rear bicycle hub assembly.

[0015] Consequently, the radial projection can prevent unnecessary axial displacement of the first sprocket relative to the sprocket support section of the rear bicycle hub assembly.

[0016] Preferably, the radial projection is designed to abut or border against the first bicycle-outward directed surface of the first chainring in the state in which the rear bicycle chainring assembly is / is mounted to the rear bicycle hub assembly.

[0017] Consequently, the radial projection can prevent superfluous or unnecessary axial displacement of the first sprocket with respect to the sprocket support section of the rear bicycle hub assembly.

[0018] Preferably, the radial projection is designed to indirectly abut or border against the first bicycle-outward directed surface of the first chainring via an intermediate link, in the state in which the rear bicycle chainring assembly is / is mounted to the rear bicycle hub assembly.

[0019] Consequently, the radial projection can prevent superfluous or unnecessary axial displacement of the first sprocket with respect to the sprocket support section of the rear bicycle hub assembly.

[0020] Preferably, the first sprocket has a first total number of teeth that is equal to or less than ten.

[0021] Consequently, it is possible to mount the first sprocket, which has a radially small number of teeth (less than or equal to ten), to the rear bicycle hub assembly with the locking link. Accordingly, a bicycle fitted with this rear sprocket assembly can have a wide gear ratio range.

[0022] Preferably, the first sprocket has a first total number of teeth. The second sprocket can have a second total number of teeth that is greater than the first total number of teeth.

[0023] Consequently, it is possible to mount the first and second sprockets, which are radially small sprockets, to the rear bicycle hub assembly with the locking link. Accordingly, a cyclist can have several gear options across a wide range of gear ratios with respect to the rear bicycle sprocket assembly.

[0024] Preferably, the first set of teeth has a total number of teeth equal to or less than ten. Preferably, the second set of teeth has a total number of eleven.

[0025] Consequently, it is possible to mount the first and second sprockets, which are radially small sprockets, to the rear bicycle hub assembly with the locking link. Accordingly, a cyclist has more gear options across a wider range of gear ratios with respect to the rear bicycle chainring assembly.

[0026] Preferably, the first sprocket has an axially recessed section formed on the first surface facing away from the bicycle. This axially recessed section can be designed to accommodate the radial projection of the locking element when the rear bicycle sprocket assembly is mounted to the rear bicycle hub assembly.

[0027] Consequently, the axially recessed section can accommodate the radial projection of the locking element without the radial projection of the locking element protruding from the first sprocket in the axial direction. Accordingly, the rear bicycle sprocket assembly can be reduced in size in the axial direction.

[0028] Preferably, the radial projection has a first inclined surface. The axially recessed section can have a second inclined surface that aligns with the first tapered surface of the radial projection when the rear bicycle chainring assembly is / is mounted to the rear bicycle hub assembly.

[0029] Consequently, the radial projection can securely fasten the first sprocket to the rear bicycle hub assembly. Furthermore, the first inclined surface of the radial projection and the second inclined surface of the axially recessed section can provide a guide function for the locking link relative to the first sprocket while the locking link is / is being screwed into the rear bicycle hub assembly.

[0030] Preferably, the first sprocket includes a first radial inner circumferential surface with respect to the axis of rotation, wherein the first radial inner circumferential surface defines the first opening. The locking element can have a radial outer surface which is configured to support the first radial inner circumferential surface of the first sprocket in the state in which the rear bicycle sprocket assembly is / is mounted to the rear bicycle hub assembly.

[0031] Consequently, the locking element can stabilize a radial position of the first sprocket.

[0032] Preferably, the first sprocket includes a first radial inner circumferential surface with respect to the axis of rotation. The first radial inner circumferential surface can define the first opening. The locking element can have a radial outer surface which is configured to be spaced radially away from the first radial inner circumferential surface of the first sprocket with respect to the axis of rotation when the rear bicycle sprocket assembly is mounted to the rear bicycle hub assembly.

[0033] Consequently, a gap or distance is formed between the first radial inner circumferential surface of the first sprocket and the radial outer surface of the locking link in the state in which the rear bicycle sprocket assembly is / is mounted to the rear bicycle hub assembly, and the gap or distance can accommodate or absorb a dimensional tolerance of the first radial inner circumferential surface of the first sprocket and the radial outer surface of the locking link.

[0034] Preferably, the external thread section of the locking element has a first axial length. The radial outer surface of the locking element may have a second axial length. The first axial length of the external thread section may be greater than the second axial length of the radial outer surface.

[0035] Consequently, the locking link can be screwed into the rear bicycle hub assembly far enough to be reliably fastened to the rear bicycle hub assembly.

[0036] Preferably, the radial projection is integrally formed with the main body as a single, integral unit element.

[0037] Consequently, it is possible to improve the stiffness of the radial protrusion.

[0038] Preferably, the radial projection has a ring-shaped flange form.

[0039] It is preferably possible to improve the stiffness of the radial projection.

[0040] Preferably, the second sprocket includes a second inward-facing surface, a second outward-facing surface, a second torque transmission structure, and a third torque transmission structure. The second outward-facing surface can be axially opposite to the second inward-facing surface. The second torque transmission structure can be located on the second inward-facing surface. The third torque transmission structure can be located on the second outward-facing surface. The third torque transmission structure can be configured to engage with the first torque transmission structure when the rear sprocket assembly is mounted to the rear hub assembly.

[0041] Consequently, it is possible to mount the first and second sprockets, which are radially small sprockets, to the rear bicycle hub assembly with the locking link. Accordingly, a cyclist can have more gear options across a wider range of gear ratios with respect to the rear bicycle chainring assembly.

[0042] Preferably, the second torque transmission structure is designed to engage with a torque transmission structure provided on the chainring support section of the rear bicycle hub assembly in the state in which the rear bicycle chainring assembly is mounted to the rear bicycle hub assembly.

[0043] Consequently, it is possible to reliably transmit the pedal torque from the first chainring to the rear bicycle hub assembly via the second chainring.

[0044] Preferably, the rear bicycle chainring assembly further comprises a plurality of additional chainrings, each of which is larger than the first chainring and the second chainring.

[0045] Consequently, it is possible to mount a variety of additional sprockets to the rear bicycle hub assembly with the locking link. Accordingly, a bicycle fitted with this rear sprocket assembly can have a wide range of gear ratios.

[0046] Preferably, the rear bicycle sprocket assembly further comprises a third sprocket. The second sprocket can include a second inward-facing surface, a second outward-facing surface, a second torque transmission structure, and a third torque transmission structure. The second outward-facing surface can be axially opposite or aligned with the second inward-facing surface. The second torque transmission structure can be located on the second inward-facing surface. The third torque transmission structure is preferably located on the second outward-facing surface.The third torque transmission structure can be configured to engage with the first torque transmission structure of the first sprocket when the rear bicycle sprocket assembly is mounted to the rear bicycle hub assembly. The third sprocket can include a third inward-facing surface, a third outward-facing surface, and a fourth torque transmission structure. The third outward-facing surface can be axially opposite the third inward-facing surface. The fourth torque transmission structure can preferably be located on the third inward-facing surface.The fourth torque transmission structure can be configured to engage with a torque transmission structure provided at the chainring support section of the rear bicycle hub assembly in the state in which the rear bicycle chainring assembly is mounted to the rear bicycle hub assembly.

[0047] Consequently, it is possible to mount the first three sprockets, which are radially small, to the rear bicycle hub assembly with the locking link. Accordingly, a rider of a bicycle equipped with this rear sprocket assembly can have more gear options across a wider range of gear ratios.

[0048] Preferably, the first sprocket has a first total number of teeth. The second sprocket preferably has a second total number of teeth that is greater than the first total number of teeth. The third sprocket preferably has a third total number of teeth that is greater than the second total number of teeth.

[0049] Consequently, it is possible to mount the first three sprockets, which are radially small, to the rear bicycle hub assembly with the locking link. Accordingly, a cyclist can have multiple gear options across a wide range of gear ratios with respect to the rear bicycle chainring assembly.

[0050] Preferably, the second torque transmission structure includes a multitude of second splines.

[0051] Consequently, it is possible to reliably transfer the pedal torque from the second chainring to the chainring support section of the rear bicycle hub assembly.

[0052] Preferably, the third torque transmission structure includes a multitude of third splines.

[0053] Consequently, it is possible to reliably transfer the pedal torque from the first sprocket to the second sprocket. Brief description of the drawings

[0054] A more complete appreciation of the invention and many of its associated advantages will become immediately apparent once it is better understood by reference to the following detailed description, when viewed in conjunction with the accompanying drawings. Fig. Figure 1 is a top view of a rear bicycle chainring assembly attached to a rear bicycle hub assembly according to a first embodiment. Fig. Figure 2 shows a partial cross-sectional view of the rear bicycle chainring assembly, illustrated in Fig. 1. Fig. Figure 3 is an enlarged partial cross-sectional view of part P of the rear bicycle chainring assembly, illustrated in Fig. 2. Fig. Figure 4 is a perspective exploded view of a part of the rear bicycle chainring assembly illustrated in Fig. 1. Fig. Figure 5 is a perspective exploded view of a part of the rear bicycle chainring assembly illustrated in Fig. 1. Fig. Figure 6 is an enlarged partial cross-sectional view of Part P of the rear bicycle chainring assembly according to a second embodiment. Fig. Figure 7 is an enlarged partial cross-sectional view of Part P of the rear bicycle chainring assembly according to a third embodiment. Description of the embodiments

[0055] The embodiments are now described with reference to the attached drawings, where similar reference numerals denote corresponding or identical elements across the different drawings. First embodiment

[0056] Fig. Figure 1 illustrates a rear bicycle chainring assembly 10 attached to a rear bicycle hub assembly 1 according to a first embodiment. In the present application, the following directional terms "front", "rear", "forward", "backward", "left", "right", "transverse", "upward" and "downward", as well as any similar directional terms, refer to directions determined by a user (e.g. a rider) sitting on a saddle (not shown) of a bicycle (not shown) facing a handlebar.Accordingly, these terms, as used herein to describe the rear bicycle hub assembly 1 and the rear bicycle chainring assembly 10, should be interpreted relative to the bicycle equipped with the rear bicycle hub assembly 1 and the rear bicycle chainring assembly 10, as used in an upright bicycle position on a horizontal surface.

[0057] As in Fig. As shown in Figure 2, the rear bicycle hub assembly 1 comprises a hub axle 2, a hub shell 3, and a sprocket support section 4. The hub axle 2 defines a pivot axis Ax. The pivot axis Ax can be considered to be the pivot axis Ax of the rear bicycle sprocket assembly 10, since the rear bicycle sprocket assembly 10 is mounted coaxially to the rear bicycle hub assembly 1. The hub axle 2 has a tubular shape and extends along the pivot axis Ax. The hub axle 2 is secured to the bicycle frames FR1 and FR2 by a wheel locking arrangement (not shown). The bicycle frames FR1 are characterized by a left seat stay and a left chainstay. The bicycle frames FR2 are characterized by a right seat stay and a right chainstay. The hub shell 3 is rotatably mounted on the hub axle 2 to rotate with respect to the pivot axis Ax.The chainring support section 4 is rotatably mounted on the hub axle 2 to rotate with respect to the axis of rotation Ax. The bicycle frames FR1, FR2 define an axial centerline CL of the rear bicycle hub assembly 2, which extends to the center of the bicycle frames FR1, FR2 when viewed from a radial direction perpendicular to the axis of rotation Ax.

[0058] As in Fig. As can be seen in Figure 2, the sprocket support section 2 is designed to support the rear bicycle sprocket assembly 10. That is, the rear bicycle sprocket assembly 10 is designed to be mounted to the sprocket support section 4 of the rear bicycle hub assembly 1. The sprocket support section 4 includes a torque transmission structure 4s on a radial outer circumferential surface of the sprocket support section 4. The torque transmission structure 4s can have a variety of splines ( Fig. 4 and Fig. 5) include. The chainring support section 4 is designed to absorb a rotational force from the rear bicycle chainring assembly 10 during cycling. The rear bicycle hub assembly comprises a first bearing unit 5 and a second bearing unit 6. The first bearing unit 5 and the second bearing unit 6 are positioned between the hub axle 2 and the hub shell 3 to rotatably support the hub shell 3 relative to the hub axle 2 with respect to the axis of rotation Ax.

[0059] The rear bicycle hub assembly comprises a third bearing unit 7 and a fourth bearing unit 8. The third bearing unit 7 and the fourth bearing unit 8 are positioned between the hub axle 2 and the sprocket support section 4 to rotatably support the sprocket support section 4 relative to the hub axle 2 with respect to the pivot axis Ax. Each of the third bearing unit 7 and the fourth bearing unit 8 has an annular shape. An outer surface of the third bearing unit 7 is secured to the sprocket support section 4, and an inner surface of the third bearing unit 7 is secured to the hub axle 2. An outer surface of the fourth bearing unit 8 is secured to the sprocket support section 4, and an inner surface of the fourth bearing unit 8 is secured to the hub axle 2.At least one of the third bearing unit 7 and the fourth bearing unit 8 can have the same structure as the first bearing unit 5 and the second bearing unit 6, if required and / or desired. At least one of the first to fourth bearing units 5 to 8 can be a plain bearing, whereas each of the first to fourth bearing units 5 to 8 is a roller bearing in the illustrated embodiment.

[0060] The rear bicycle hub assembly 1 includes an end cap 9. The end cap 9 is mounted to the hub axle 2 to abut against an inner surface of the fourth bearing unit 8. The end cap 9 is fixed to an elastomeric link 9r (e.g., an O-ring 9r) at a position where the end cap 9 can abut against the inner surface of the fourth bearing unit 8.

[0061] The rear bicycle sprocket assembly 10 comprises sprockets SP1 to SP11. The total number of sprockets SP1 to SP11 is not limited to the illustrated embodiment. Sprockets SP1 to SP8 are conventional bicycle sprockets. Some of the sprockets SP1 to SP8 can be connected to a sprocket carrier having a plurality of splines, and the plurality of splines of the sprocket carrier can engage with the torque transmission structure 4s of the sprocket support section 4. In the illustrated embodiment, sprockets SP1 and SP2 are mounted on a first sprocket carrier SC1, and sprockets SP3 to SP4 are mounted on a second sprocket carrier SC2. The other sprockets SP1 to SP8 can have splines and engage with the torque transmission structure 4s of the sprocket support section 4.The total number of sprockets SP1 to SP8 is not limited to the illustrated embodiment. In this embodiment, sprocket SP11, sprocket SP10, and sprockets SP1 to SP9 can each be referred to as a first sprocket, a second sprocket, and a plurality of additional sprockets, respectively. The rear bicycle sprocket assembly 10 comprises a plurality of additional sprockets SP1 to SP9, each larger than the first sprocket SP11 and the second sprocket SP10. Nevertheless, sprocket SP9 can be referred to as a third sprocket.

[0062] As in Fig. As shown in Figure 3, the rear bicycle chainring assembly 10 comprises a first chainring 12 (SP12) and a locking link 26. The first chainring 12 includes a first tooth section 12t and a first chainring body 12b. The first tooth section 12t has a plurality of teeth. In the following description, the total number of teeth of the first chainring 12 is referred to as the first total number of teeth. The first chainring 12 has the first total number of teeth. Preferably, the first total number of teeth is equal to or less than ten.

[0063] The first sprocket body 12b includes a first bicycle-inward facing surface 14, a first bicycle-outward facing surface 16, a first torque transmission structure 18, a first radial inner circumferential surface 20, and a first connecting section 22. The first radial inner circumferential surface 20 defines a first opening 24. That is, the first sprocket 12b includes the first radial inner circumferential surface 20 with respect to the axis of rotation Ax. The first sprocket 12b includes the first bicycle-inward facing surface 14, the first bicycle-outward facing surface 16, the first opening 24, and the first torque transmission structure 18. The first bicycle-inward facing surface 14 is directed toward the axial centerline CL of the rear bicycle hub assembly 1.The first bicycle-outward-facing surface 16 is opposite to the first bicycle-inward-facing surface 14 in an axial direction Da, parallel to the axis of rotation Ax of the rear bicycle chainring assembly 10. In other words, the first bicycle-outward-facing surface 16 is oriented in the opposite direction or backward with respect to the axial direction Da, compared to the first bicycle-inward-facing surface 14. The first opening 24 has a first diameter D1, which is smaller than a radial outer diameter D0 of the chainring support section 4 of the rear bicycle hub assembly 1.

[0064] The first torque transmission structure 18 is designed to transmit a pedal torque to a second sprocket 38 (SP10), adjacent to the first sprocket 12, without any further sprocket between the first sprocket 12 and the second sprocket 38 in the axial direction Da. The first torque transmission structure 18 is connected to the first bicycle-inward facing surface 14 via the first connecting section 22. That is, the first torque transmission structure 18 is provided at the first bicycle-inward facing surface 14. The first connecting section 22 has an axial length in the axial direction Da, which is equal to a sprocket pitch P1 ( Fig. 1) between the first sprocket 12 and the second sprocket 38 in the axial direction. There is.

[0065] The locking element 26 comprises a main body 28, an external threaded section 30, and a radial projection 32. The main body 28 has a first axial end 28fe and a second axial end 28re. The first axial end 28fe is configured to pass through the first opening 24 of the first sprocket 12. The first axial end 28fe is directed towards the axial centerline CL of the rear bicycle hub assembly 1. The second axial end 28re is opposite the first axial end 28fe in the axial direction Da. In other words, the second axial end 28re is located on the other side of the first axial end 28fe in the axial direction Da. The first axial end 28fe is positioned closer to the axial centerline CL of the rear bicycle hub assembly 1 than the second axial end 28re, in a state in which the rear bicycle chainring assembly 10 is / is mounted to the rear bicycle hub assembly 1.The main body 28 of the locking element 26 has a second diameter D2 which is equal to or smaller than the first diameter D1 of the first opening 24 of the first sprocket 12.

[0066] The external threaded section 30 is provided at the first axial end 28fe. More specifically, the external threaded section 30 is provided near the first axial end 28fe. The sprocket support section 4 further includes an internal threaded section 4t on a radial inner circumferential surface of the sprocket support section 4. Each of the internal threaded section 4t and the external threaded section 30 includes a threaded groove. The external threaded section 30 is designed to engage with the internal threaded section 4t of the rear bicycle hub assembly 1 when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1.

[0067] As in the Fig. 3, Fig. 4 to Fig. As can be seen in Figure 5, the radial projection 32 has an annular flange shape. The radial projection 32 can have a pin-like shape. The radial projection 32 can have a plurality of projections, each of which has a pin-like shape. The plurality of pin-like projections can be arranged at the second axial end 28re to be spaced apart from one another at regular intervals in a circumferential direction with respect to the axis of rotation Ax. The radial projection 32 is integrally formed with the main body 28 as a single, integral element. Alternatively, the radial projection 32 can be a separate element from the main body 28. In such a case, the radial projection 32 can be attached to the main body 28 by an adhesive, a welding process, or by diffusion bonding. The locking element 26 is preferably made of a metallic material such as aluminum or iron.The radial projection 32 can be made of a metallic material different from that of the main body 28.

[0068] As in Fig. As can be seen in Figure 3, the radial projection 32 extends radially outwards from the second axial end 28re with respect to the axis of rotation Ax, in order to limit axial displacement of the first sprocket 12 with respect to the sprocket support section 4 of the rear bicycle hub assembly 1, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. That is to say, the radial projection 32 is designed to abut against the first bicycle-outward facing surface 16 of the first sprocket 12, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. The radial projection 32 is positioned further away from the axial centerline CL of the rear bicycle hub assembly 1 than the first bicycle-inward directed surface 14 of the first sprocket 12, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1.

[0069] As in Fig. As can be seen in Figure 3, the first sprocket 12 has an axially recessed section 17 formed on the first surface 16 facing away from the bicycle. More specifically, the first sprocket body 12b includes the axially recessed section 17. The axially recessed section 17 is recessed in the axial direction Da. The axially recessed section 17 is designed to accommodate the radial projection 32 of the locking element 26 when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. The radial projection 32 has a first inclined surface 34. The axially recessed section 17 has a second inclined surface 17s that aligns with the first tapered surface 34 of the radial projection 32 when the rear bicycle sprocket assembly 10 is / is mounted to the rear bicycle hub assembly 1.

[0070] The locking element 26 has a radial outer surface 36 between the external thread section 30 and the first tapered surface 34 in the axial direction Da. The radial outer surface is designed to be spaced radially Dr from the first radial inner circumferential surface 20 of the first sprocket 12 with respect to the axis of rotation Ax when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. The radial direction Dr is perpendicular to the axial direction Da. The external thread section 30 of the locking element 26 has a first axial length L1 in the axial direction Da. The radial outer surface 36 of the locking element 26 has a second axial length L2 in the axial direction Da. The first axial length L1 of the external thread section 30 is greater than the second axial length L2 of the radial outer surface 36.

[0071] As in Fig. As shown in Figure 3, the rear bicycle chainring assembly 10 further comprises the second chainring 8 (SP10). The second chainring 38 includes a second tooth section 38t and a second chainring body 38b. The second tooth section 38t has a plurality of teeth. In the following description, the total number of teeth of the second chainring 38 is referred to as the second total number of teeth. The second chainring 38 has a second total number of teeth that is greater than the first total number of teeth. Preferably, the second total number of teeth is eleven.

[0072] The second sprocket 38b includes a second bicycle-inward facing surface 40, a second bicycle-outward facing surface 42, a second torque transmission structure 44, a third torque transmission structure 46, a second connecting section 48, and a projecting section 50. That is, the second sprocket 38 includes the second bicycle-inward facing surface 40, the second bicycle-outward facing surface 42, the second torque transmission structure 44, and the third torque transmission structure 46. The second bicycle-inward facing surface 40 is directed toward the axial centerline CL of the rear bicycle hub assembly 1. The second bicycle-outward facing surface 42 is opposite, or oriented in the axial direction Da, to the second bicycle-inward facing surface 40. In other words, the second bicycle-outward facing surface 42 is oriented in a reversible direction.Reverse direction with respect to the axial direction Da directed in comparison to the second bicycle-inward directed surface 40.

[0073] The second torque transmission structure 44 is connected to the second bicycle-inward facing surface 40 via the second connecting section 48. This means that the second torque transmission structure 44 is provided at the second bicycle-inward facing surface 40. The second connecting section 48 has an axial length Da in the axial direction that is shorter than one sprocket pitch P2 ( Fig. 1) between the second sprocket 38 and the third sprocket 52. As in Fig. As can be seen in Figure 4, the second torque transmission structure 44 includes a plurality of second splines 44s. The plurality of second splines 44s can engage with the plurality of splines included in the torque transmission structure 4s. That is, the second torque transmission structure 44 is designed to engage with the torque transmission structure 4s provided at the sprocket support section 4 of the rear bicycle hub assembly 1, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1.

[0074] The third torque transmission structure 46 is formed on the second bicycle-outward facing surface 42. The third torque transmission structure 46 is provided on the second bicycle-outward facing surface 42. The third torque transmission structure 46 is recessed in the axial direction Da to accommodate the first torque transmission structure 18 of the first sprocket 12. As shown in Fig. As can be seen in Figure 5, the third torque transmission structure 46 includes a plurality of third splines 46s. The first torque transmission structure 18 includes a plurality of first splines 18s. The first splines 18s can engage with the third splines 46s. This means that the third torque transmission structure 46 is designed to engage with the first torque transmission structure 18 in the state where the rear bicycle chainring assembly 10 is mounted to the rear bicycle hub assembly 1. As shown in Figure 5, the third torque transmission structure 46 is designed to engage with the first torque transmission structure 18 when the rear bicycle chainring assembly 10 is mounted to the rear bicycle hub assembly 1. Fig. As can be seen in Figure 3, the projecting section 50 extends from the second connecting section 48 in the axial direction Da. The projecting section 50 is positioned radially outwards from the second torque transmission structure 44 with respect to the axis of rotation Ax. The projecting section 50 is received in a stepped recess 54 of the third sprocket 52.

[0075] As in Fig. As shown in Figure 3, the rear bicycle chainring assembly 10 further comprises the third chainring 52 (SP9). The third chainring 52 includes a third tooth section 52t and a third chainring body 52b. The third tooth section 52t has a plurality of teeth. In the following description, the total number of teeth of the third chainring 52 is referred to as the third tooth count. The third chainring 52 has a third tooth count that is greater than the second tooth count. Preferably, the third tooth count is thirteen.

[0076] The third sprocket body 52b includes the stepped recess 54, a third bicycle-inward facing surface 56, a third bicycle-outward facing surface 58, and a fourth torque transmission structure 60. That is, the third sprocket 52 includes the third bicycle-inward facing surface 56, the third bicycle-outward facing surface 58, and the fourth torque transmission structure 60. The third bicycle-inward facing surface 56 is directed toward the axial centerline CL of the rear bicycle hub assembly 1. The third bicycle-outward facing surface 58 is opposite to the third bicycle-inward facing surface 56 in the axial direction Da. In other words, the third bicycle-outward facing surface 58 is directed in a reverse direction with respect to the axial direction Da, compared to the third bicycle-inward facing surface 56.The stepped recess 54 is formed on the third surface 58 facing away from the bicycle. The stepped recess 54 is cut out in the axial direction Da to accommodate the projecting section 60 of the second chainring 38.

[0077] The fourth torque transmission structure 60 extends from the stepped recess 54 to the fourth sprocket SP8 in the axial direction Da. This means that the fourth torque transmission structure 60 is provided on the third bicycle-inward facing surface 56. The fourth torque transmission structure 60 has an axial length in the axial direction Da which is longer than one sprocket pitch P3 ( Fig. 1) between the third sprocket 52 and the fourth sprocket SP8. As in the Fig. 4 and Fig. As can be seen in Figure 5, the fourth torque transmission structure 60 includes a plurality of fourth splines 60s. The plurality of fourth splines 60s can engage with the plurality of splines included in the torque transmission structure 4s. That is, the fourth torque transmission structure 60 is designed to engage with the torque transmission structure 4s provided at the sprocket support section 4 of the rear bicycle hub assembly 1, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1.

[0078] The rear bicycle chainring assembly 10 includes the following features. (1) The rear bicycle chainring assembly 10 comprises the first chainring 12 and the locking link 26. The first chainring 12 comprises the first opening 24 and the first torque transmission structure 18. The first opening 24 has the first diameter D1, which is smaller than the radial outer diameter D0 of the chainring support section 4. The first torque transmission structure 18 is provided on the first bicycle-inward facing surface 14 and is configured to transmit the pedal torque to the second chainring 38. The locking link 26 comprises the main body 28, the external threaded section 28fe, which is configured to pass through the first opening 24 of the first chainring 12, and the second axial end 28re, which is opposite the first axial end 28fe in the axial direction Da. The external threaded section 30 is provided on the first axial end 28fe.The external threaded section 30 is designed to engage with the internal threaded section 4t of the rear bicycle hub assembly 1 when the rear bicycle chainring assembly 10 is mounted to the rear bicycle hub assembly 1. The radial projection 32 extends radially outward from the second axial end 28re with respect to the axis of rotation Ax to limit the axial displacement of the first chainring 12 with respect to the chainring support section 4 of the rear bicycle hub assembly 1 when the rear bicycle chainring assembly 10 is mounted to the rear bicycle hub assembly 1. Accordingly, it is possible to mount the first chainring 12, which has a radially small number of teeth (less than or equal to ten), to the rear hub assembly 1 with the locking element 26.Therefore, a bicycle fitted with the rear chainring assembly 10 can have a wide gear ratio range. (2) The main body 28 of the locking element 26 has a second diameter D2 which is equal to or smaller than the first diameter D1 of the first opening 24 of the first sprocket 12. (3) The radial projection 32 is positioned further away from the axial center line CL of the rear bicycle hub assembly 1 than the first bicycle-inward facing surface 14 of the first sprocket 12, in the state in which the rear bicycle sprocket assembly 10 is / is mounted to the rear bicycle hub assembly 1. (4) The radial projection 32 is designed to abut against the first bicycle-outward directed surface 16 of the first chain wheel 12 in the state in which the rear bicycle chain wheel assembly 10 is / is mounted on the rear bicycle hub assembly 1. (5) The first sprocket 12 has the first total number of teeth which is equal to or less than ten. (6) The second sprocket 38 includes the second bicycle-inward facing surface 40, the second torque transmission structure 44, and the third torque transmission structure 46. The second torque transmission structure 44 is provided on the second bicycle-inward facing surface 40. The third torque transmission structure 46 is configured to engage with the first torque transmission structure 18 when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. (7) The second sprocket 38 has a second total number of teeth that is greater than the first total number of teeth. More specifically, the first total number of teeth is equal to or less than ten, and the second total number of teeth is eleven. (8) The second torque transmission structure 44 is designed to engage with the torque transmission structure 4s provided at the chainring support section 4 of the rear bicycle hub assembly when the rear bicycle chainring assembly is mounted to the rear bicycle hub assembly 1. (9) The first sprocket 12 has the axially recessed section 17, which is formed on the first surface 16 facing away from the bicycle. The axially recessed section 17 is designed to accommodate the radial projection 32 of the locking element 26 when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. (10) The radial projection 32 has the first inclined surface 34. The axially recessed section 17 has the second inclined surface 17s, which fits with the first tapered surface 34 of the radial projection 32, in the state in which the rear bicycle chainring assembly 10 is mounted to the rear bicycle hub assembly 1. (11) The first sprocket 12 includes the first radial inner circumferential surface 20 with respect to the axis of rotation Ax. The first radial inner circumferential surface 20 defines the first opening 24. The locking element 26 has the radial outer surface 36, which is designed to be spaced apart from the first radial inner circumferential surface 20 of the first sprocket 12 in the radial direction Dr with respect to the axis of rotation Ax, in the state in which the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. (12) The external threaded section 30 of the locking element 26 has a first axial length L1 in the axial direction Da. The radial outer surface 36 of the locking element 26 has a second axial length L2 in the axial direction Da. The first axial length L1 of the external threaded section 30 is greater than the second axial length L2 of the radial outer surface 36. (13) The third sprocket 52 includes the bicycle-inward facing surface 56 and the fourth torque transmission structure 60. The fourth torque transmission structure 60 is provided on the third bicycle-inward facing surface 56. The fourth torque transmission structure 60 is configured to engage with the torque transmission structure 4s, provided on the sprocket support section 4 of the rear bicycle hub assembly 1, when the rear bicycle sprocket assembly 10 is mounted to the rear bicycle hub assembly 1. (14) The third sprocket 52 has the third total number of teeth, which is greater than the second total number of teeth. (15) The first torque transmission structure 18 includes a plurality of first splines 18s. (16) The second torque transmission structure 44 includes a plurality of second splines 44s. (17) The third torque transmission structure 46 includes a plurality of third splines 46s. (18) The radial projection 32 is integrally provided with the main body 28 as a one-piece unit element. (19) The radial projection 32 has an annular flange shape. (20) The rear bicycle chainring assembly 10 further includes a plurality of additional chainrings SP1 to SP8, each of which is larger than the first chainring 12 and the second chainring 38. Second embodiment

[0079] A rear bicycle chainring assembly 210 according to a second embodiment is described below with reference to Fig. 6 described. The rear bicycle chainring assembly 210 has essentially the same structure as that of the rear bicycle chainring assembly 10 for the first chainring 12 and the locking link 26. Consequently, the elements that have essentially the same function as in the first embodiment are given the same reference numerals herein for the sake of brevity and are not described and / or illustrated in detail.

[0080] As in Fig. As shown in Figure 6, the rear bicycle sprocket assembly 210 comprises a first sprocket 212 and a locking link 226. The first sprocket 212 includes the first tooth section 12t and a first sprocket body 212b. Unlike the first sprocket body 12b of the first embodiment, the first sprocket body 212b includes an axially recessed section 217 instead of the axially recessed section 17 in the first embodiment. The axially recessed section 217 is recessed in the axial direction Da. The axially recessed section 217 provides an opening larger than the first opening 24 in the radial direction Dr. The rear bicycle sprocket assembly 210 further comprises an intermediate link 62. The intermediate link 62 can be, for example, a washer. The intermediate link 62 is arranged in the opening provided in the axially recessed section 217.The locking element 226 comprises the main body 28, the external threaded section 30, and a radial projection 232. The radial projection 232 has a shape similar to a flange. The radial projection 232 is designed to indirectly abut or border against the first bicycle-outward facing surface 16 of the first sprocket 212 via the intermediate link 62 in the state in which the rear bicycle sprocket assembly 210 is mounted to the rear bicycle hub assembly 1.

[0081] With the rear bicycle chainring assembly 210, it is possible to achieve essentially the same advantages as with the rear bicycle chainring assembly 10 according to the first embodiment.

[0082] Furthermore, the rear bicycle chainring assembly 210 includes the following features. The radial projection 232 is designed to indirectly abut or border against the first bicycle-outward facing surface of the first chainring 12 via the intermediate link 62 in the state in which the rear bicycle chainring assembly 210 is mounted to the rear bicycle hub assembly 1. Third embodiment

[0083] A rear bicycle chainring assembly 310 according to a third embodiment is described below with reference to Fig. 7 described. The rear bicycle chainring assembly 310 has essentially the same structures as the rear bicycle chainring assembly 10, except for at least one of the first chainring 12 and the locking link 26. Consequently, the elements that have essentially the same function as those in the first embodiment are designated with the same reference numerals and are not described and / or illustrated again in detail herefor the sake of brevity.

[0084] As in Fig.As shown in Figure 7, the rear bicycle chainring assembly 310 comprises a first chainring 312 and a locking link 326. The first chainring 312 and the locking link 326 have essentially the same structures as the first chainring 12 and the locking link 26, except for the positional relationship between the first radial inner circumferential surface 20 and the radial outer surface 36. In the following description, the first radial inner circumferential surface 20 is referred to as a first radial inner circumferential surface 320 in the third embodiment, and the radial outer surface 36 is referred to as a radial outer surface 336 in the third embodiment. In this embodiment, at least a part of the first radial inner circumferential surface 320 is in contact with the radial outer surface 336.This means that the locking element 326 has the radial outer surface 336 which is designed to support the first radial inner circumferential surface 320 of the first sprocket 312 in the state in which the rear bicycle sprocket assembly 310 is mounted to the rear bicycle hub assembly 1.

[0085] With the rear bicycle chainring arrangement 310, it is possible to achieve essentially the same advantages as with the rear bicycle chainring arrangement 10 according to the first embodiment.

[0086] Furthermore, the rear bicycle chainring assembly 310 includes the following features. The locking element 326 has the radial outer surface 336, which is designed to support the first radial inner circumferential surface 320 of the first chainring 312 in the state in which the rear bicycle chainring assembly 310 is mounted to the rear bicycle hub assembly 1.

[0087] It will be apparent to a person skilled in the art of bicycles from the present disclosure that the structures and / or designs of the foregoing embodiments can be combined at least partially.

[0088] The term "comprehensive" and its derivatives, as used herein, are intended to be open terms that specify the presence of the mentioned features, elements, components, groups, integers, and / or steps, but do not exclude the presence of the unmentioned features, elements, components, groups, integers, and / or steps. This concept also applies to words with similar meanings, such as "exhibit," "include," and their derivatives.

[0089] The terms “link”, “section”, “part”, “element”, “body” and “structure”, when used in the singular, can have the dual meaning of a single part or a multitude of parts.

[0090] The integers, such as "first" and "second," as cited in the present application, are merely identifying marks and have no other meaning, such as indicating a specific order or the like. Furthermore, the term "first element," for example, does not itself imply the existence of a second element, and the term "second element" does not itself imply the existence of a first element.

[0091] The term “a pair of”, as used herein, can include the configuration in which the pair of elements have different shapes or structures relative to each other, and additionally the configuration in which the pair of elements have the same shape or structure relative to each other.

[0092] Finally, the magnitude terms such as "essentially", "by" and "approximately", as used herein, signify a reasonable amount of deviation of the modified term such that the final result is not significantly altered.

[0093] Naturally, numerous modifications and variations of the present invention are possible in light of the foregoing teachings. It should be understood that, within the scope of the appended claims, the invention can be implemented in ways other than those specifically described herein.

Claims

[1] Rear bicycle chainring assembly (10; 210; 310), designed to be mounted to a chainring support section (4) of a rear bicycle hub assembly (1), the rear bicycle chainring assembly (10; 210; 310) comprising: a first sprocket (SP11; 12; 212; 312), a second sprocket (SP10; 38) and a locking link (26; 226; 326), wherein the first sprocket (SP11; 12; 212; 312) includes: a first bicycle-inward directed surface (14); a first bicycle-outward directed surface (16), opposite to the first bicycle-inward directed surface (14) in an axial direction (Da), parallel to a rotation center axis (Ax) of the rear bicycle chainring assembly (10; 210; 310); a first opening (24) having a first diameter (D1) that is smaller than a radial outer diameter (D0) of the sprocket support section (4) of the rear bicycle hub assembly (1); and A first torque transmission structure (18) provided on the first bicycle-inward facing surface (14) and configured to transmit a pedal torque to the second sprocket (SP10; 38), adjacent to the first sprocket (SP11; 12; 212; 312), without a further sprocket between the first sprocket (SP11; 12; 212; 312) and the second sprocket (SP10; 38) in the axial direction (Da), preferably the first torque transmission structure (18) includes a plurality of first splines (18s); and wherein the locking element (26; 226; 326) includes: comprising a main body (28) having a first axial end (28fe) configured to pass through the first opening (24) of the first sprocket (SP11; 12; 212; 312), and a second axial end (28re) opposite the first axial end (28fe) in the axial direction (Da), wherein the first axial end (28fe) is positioned closer to an axial centerline (CL) of the rear bicycle hub assembly (1) than the second axial end (28re), in a state in which the rear bicycle sprocket assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1); an external threaded section (30) provided at the first axial end (28fe), wherein the external threaded section (30) is configured to engage with an internal threaded section (4t) of the rear bicycle hub assembly (1) in the state in which the rear bicycle chainring assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1); and a radial projection (32) which extends radially outwards from the second axial end (28re) with respect to the axis of rotation (Ax) in order to limit an axial displacement of the first sprocket (SP11; 12; 212; 312) with respect to the sprocket support section (4) of the rear bicycle hub assembly (1) in the state in which the rear bicycle sprocket assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [2] Rear bicycle chainring assembly (10; 210; 310) according to claim 1, wherein the main body (28) of the locking element (26; 226; 326) has a second diameter (D2) which is equal to or smaller than the first diameter (D1) of the first opening (24) of the first chainring (SP11; 12; 212; 312). [3] Rear bicycle chainring assembly (10; 210; 310) according to claim 1 or 2, wherein the radial projection (32) is positioned further away from the axial center line (CL) of the rear bicycle hub assembly (1) than the first bicycle-inward directed surface (14) of the first chainring (SP11; 12; 212; 312) in the state in which the rear bicycle chainring assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [4] Rear bicycle chainring assembly (10; 210; 310) according to one of claims 1 to 3, wherein the radial projection (32) is configured to either abut against the first bicycle-outward facing surface (16) of the first chainring (SP11; 12; 212; 312) or to abut indirectly against the first bicycle-outward facing surface (16) of the first chainring (SP11; 12; 212; 312) via an intermediate link (62), both in the state in which the rear bicycle chainring assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [5] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 4, wherein the first chainring (SP11; 12; 212; 312) has a first total number of teeth equal to or less than ten. [6] Rear bicycle chainring arrangement (10; 210; 310) according to any one of claims 1 to 5, wherein the first chainring (SP11; 12; 212; 312) has a first total number of teeth; and the second chainring (SP10; 38) has a second total number of teeth which is greater than the first total number of teeth, preferably the first total number of teeth is equal to or less than ten and the second total number of teeth is eleven. [7] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 6, wherein the first chainring (SP11; 12; 212; 312) has an axially recessed section (17) formed on the first bicycle-outward directed surface (16); and the axially recessed section (17) is designed to accommodate the radial projection (32) of the locking element (26; 226; 326) in the state in which the rear bicycle chainring assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [8] Rear bicycle chainring assembly (10; 210; 310) according to claim 7, wherein the radial projection (32) has a first inclined surface (34); and the axially recessed section (17) has a second inclined surface (17s) that fits into the first inclined surface (34) of the radial projection (32), in the state in which the rear bicycle chainring assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [9] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 8, wherein the first chainring (SP11; 12; 212; 312) has a first radial inner circumferential surface (20; 320) with respect to the axis of rotation (Ax), wherein the first radial inner circumferential surface (20; 320) defines the first opening (24) and the locking element (26; 226; 326) has a radial outer surface (36) which is configured either to support the first radial inner circumferential surface of the first chainring (SP11; 12; 212; 312) or to extend from the first radial inner circumferential surface (20; 320) of the first chainring (SP11; 12; 212; 312) in a radial direction (Dr) with respect to the axis of rotation (Ax) to be spaced apart, both in the state in which the rear bicycle chainring assembly (10; 210; 310) is / is mounted to the rear bicycle hub assembly (1). [10] Rear bicycle chainring assembly (10; 210; 310) according to claim 9, wherein the external thread section (30) of the locking element (26; 226; 326) has a first axial length (L1) in the axial direction (Da); the radial outer surface (36) of the locking element (26; 226; 326) has a second axial length (L2) in the axial direction (Da); and the first axial length (L1) of the external thread section (30) is greater than the second axial length (L2) of the radial outer surface (36). [11] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 10, wherein the radial projection (32) has an annular flange shape and / or is formed integrally with the main body (28) as a one-piece unit element. [12] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 11, wherein the second chainring (SP10; 38) comprises: a second bicycle-inward directed surface (40); a second bicycle-outward directed surface (42), opposite the second bicycle-inward directed surface (40) in the axial direction (Da); a second torque transmission structure (44) provided on the second bicycle-inward directed surface (40), preferably the second torque transmission structure (44) comprising a plurality of second splines (44s); and a third torque transmission structure (46) provided on the second bicycle-outward directed surface (42), wherein the third torque transmission structure (46) is configured to engage with the first torque transmission structure (18) in the state in which the rear bicycle chainring assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1), preferably the third torque transmission structure (46) includes a plurality of third splines (46s). [13] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 12, wherein the second torque transmission structure (44) is configured to engage with a torque transmission structure (4s) provided on the chainring support section (4) of the rear bicycle hub assembly (1) in the state in which the rear bicycle chainring assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1). [14] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 13, further comprising: a variety of additional sprockets (SP1; SP2; SP3; SP4; SP5; SP6; SP7; SP8; SP9), each larger than the first sprocket (SP11; 12; 212; 312) and the second sprocket (SP10; 38). [15] Rear bicycle chainring assembly (10; 210; 310) according to any one of claims 1 to 14, further comprising a third chainring (52), wherein the second chainring (SP10; 38) includes: a second bicycle-inward directed surface (40); a second bicycle-outward directed surface (42), opposite the second bicycle-inward directed surface (40) in the axial direction (Da); a second torque transmission structure (44) provided on the second bicycle-inward facing surface (40); and a third torque transmission structure (46) provided on the second bicycle-outward facing surface (42), wherein the third torque transmission structure (46) is configured to engage with the first torque transmission structure (18) in the state in which the rear bicycle chainring assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1), and wherein the third chainring (52) comprises: a third bicycle-inward directed surface (56); a third bicycle-outward directed surface (58), opposite the third bicycle-inward directed surface (56) in the axial direction (Da); a fourth torque transmission structure (60) provided on the third bicycle-inward directed surface (56), wherein the fourth torque transmission structure (60) is configured to engage with a torque transmission structure (4s) provided on the chain wheel support section (4) of the rear bicycle hub assembly (1) in the state in which the rear bicycle chain wheel assembly (10; 210; 310) is mounted to the rear bicycle hub assembly (1). [16] Rear bicycle chainring assembly (10; 210; 310) according to claim 15, wherein the first chainring (SP11; 12; 212; 312) has a first total number of teeth; the second chainring (SP10; 38) has a second total number of teeth greater than the first total number of teeth; and the third chainring (52) has a third total number of teeth greater than the second total number of teeth.

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