Bicycle chainring and bicycle drivetrain

Abstract

A bicycle chainring (SP1 to SP12), comprising: a sprocket body (SP1A to SP12A) with a first axially oriented surface (SP1A1) and a second axially oriented surface (SP1A2) which are aligned in the axial direction (D2) with respect to a rotational center axis (A1) of the bicycle sprocket (SP1 to SP12), wherein the second axially oriented surface (SP1A2) is provided in the axial direction (D2) on a rear side of the first axially oriented surface (SP1A1), wherein the first axially oriented surface (SP1A1) is configured to point in a mounted state in which the bicycle sprocket (SP1 to SP12) is mounted on a bicycle (10) in the direction of a median plane (10A) of the bicycle (10); a plurality of sprocket teeth (SP1B to SP12B) extending radially outwards from the sprocket body (SP1A to SP12A) with respect to the axis of rotation (A1); at least one upshift facilitation area (FU1 to FU12) configured to facilitate the transfer of a bicycle chain (C) from the bicycle sprocket (SP1 to SP12) to a smaller bicycle sprocket (SP1 to SP11) located axially (D2) adjacent to the bicycle sprocket (SP1 to SP12) without another bicycle sprocket in between; wherein the plurality of sprocket teeth (SP1B to SP12B) includes at least one axially recessed, upshifting initiation tooth (SP1U to SP12U) which is axially recessed with respect to the rotational center axis (A1); wherein the at least one axially recessed upshift initiation tooth (SP1U to SP12U) is arranged and configured in the at least one upshift facilitation area (FU1 to FU12) to release an inner connecting link (C1) of the bicycle chain (C) from the at least one axially recessed upshift initiation tooth (SP1U to SP12U) during an upshift operation in which the bicycle chain (C) changes from the main chainring (SP1 to SP12) to the smaller bicycle chainring (SP1 to SP11); wherein the at least one axially recessed upshift initiation tooth (SP1U to SP12U) has a driving surface (SP1U1), a non-driving surface (SP1U2) and a tooth tip section (SP1U3); wherein the driving surface (SP1U1) includes a driving surface-side tooth tip end (E11); wherein the non-driving surface (SP1U2) includes a non-driving surface tooth tip end (E12); the tooth tip section (SP1U3) connects the driving surface side tooth tip end (E11) and the non-driving surface side tooth tip end (E12); the non-driving surface (SP1U2) which extends from the non-driving surface tooth tip end (E12) in a circumferential direction (D1) with respect to the rotation center axis (A1); the non-riding surface (SP1U2) has a non-riding surface projection (SP1U4) which is arranged radially inside the non-riding surface tooth tip end (E12) with respect to the axis of rotation (A1); and wherein the non-riding surface projection (SP1U4) has a projection tip (SP1U5) which is located in the axial direction (D2) closer to the second axially oriented surface (SP1A2) than the non-riding surface tooth tip end (E12), so that a guide chamfer (SP1U6) extends from the projection tip (SP1U5) to the first axially oriented surface (SP1A1).

Description

[0001] The present invention relates to a bicycle chainring and a bicycle drivetrain.

[0002] Cycling is becoming increasingly popular as a leisure and transportation activity. 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 its various components. One bicycle component that has undergone fundamental redesign is the chainring. Further bicycle chainrings are described in DE 10 2018 111 277 A1, DE 10 2018 208 397 A1, DE 10 2018 204 960 A1, DE 10 2015 005 454 A1, DE 10 2017 128 041 A1, and US 6 340 338 B1.

[0003] According to a first aspect of the present invention, a bicycle chainring comprises a chainring body, a plurality of chainring teeth, and at least one shifter relief area. The chainring body includes a first axially oriented surface and a second axially oriented surface, which are aligned axially with respect to a rotational center axis of the bicycle chainring. The second axially oriented surface is provided axially on a rear side of the first axially oriented surface. The first axially oriented surface is configured to point toward a median plane of the bicycle when the bicycle chainring is mounted on a bicycle. The plurality of chainring teeth extends radially outward from the chainring body with respect to the rotational center axis.The at least one upshift facilitation area is configured to facilitate the shifting of a bicycle chain from the main chainring to a smaller chainring located axially adjacent to the main chainring without any other chainring in between. The plurality of chainring teeth includes at least one axially recessed upshift initiation tooth, which is axially recessed with respect to the axis of rotation. The at least one axially recessed upshift initiation tooth is located in the at least one upshift facilitation area and is configured to disengage an inner link plate of the bicycle chain from the at least one axially recessed upshift initiation tooth during an upshift operation in which the bicycle chain shifts from the main chainring to the smaller chainring.The at least one axially recessed upshift initiation tooth comprises a driving surface, a non-driving surface, and a tooth tip section. The driving surface includes a tooth tip end on the driving surface side. The non-driving surface includes a tooth tip end on the non-driving surface side. The tooth tip section connects the tooth tip end on the driving surface side and the tooth tip end on the non-driving surface side.

[0004] The non-running surface extends circumferentially from the non-running surface tooth tip end with respect to the axis of rotation. The non-running surface includes a non-running surface projection located radially inward from the non-running surface tooth tip end with respect to the axis of rotation. The non-running surface projection has a tip that is located axially closer to the second axially oriented surface than the non-running surface tooth tip end, such that a chamfer extends from the tip of the projection to the first axially oriented surface.

[0005] With the bicycle chainring as described in the first aspect, the non-riding-surface projection restricts the upshifting process in a first chain phase, in which the position of at least one axially recessed upshift initiation tooth corresponds to the position of an opposing pair of outer link plates of the bicycle chain. The non-riding-surface projection allows the upshifting process to be carried out in a second chain phase, in which the position of at least one axially recessed upshift initiation tooth corresponds to the position of an opposing pair of inner link plates of the bicycle chain. This makes it possible to reduce the shock caused by the first chain phase during the upshifting process while maintaining the same shifting performance.

[0006] According to a second aspect of the present invention, the bicycle chainring according to the first aspect is configured such that the projection tip is arranged radially inwards from the non-riding-surface tooth tip end with respect to the axis of rotation. With the bicycle chainring according to the second aspect, it is possible to further reduce the shock caused by the first chain phase during upshifting while maintaining the same shifting performance.

[0007] According to a third aspect of the present invention, the bicycle chainring according to the first or second aspect is configured such that the projection tip of a tooth base circle of the bicycle chainring is arranged radially outside with respect to the axis of rotation. With the bicycle chainring according to the third aspect, it is possible to further reduce a shock caused by the first chain phase during upshifting while maintaining the same shifting performance.

[0008] According to a fourth aspect of the present invention, the bicycle chainring according to one of the first to third aspects is configured such that the plurality of chainring teeth adjacent to the at least one axially recessed upshift initiation tooth includes a last chain-shifting tooth. The last chain-shifting tooth is arranged, with respect to one direction of rotation, on a downstream side of the at least one axially recessed upshift initiation tooth. The last chain-shifting tooth is configured such that it is the last to disengage from an outer connecting link of the bicycle chain during the upshifting process. With the bicycle chainring according to the fourth aspect, it is possible to further reduce a shock caused by the first chain phase during the upshifting process while maintaining the same shifting performance.

[0009] According to a fifth aspect of the present invention, the bicycle chainring according to one of the first to fourth aspects is configured such that the plurality of chainring teeth adjacent to the at least one axially recessed upshift initiation tooth includes at least one axially recessed tooth without any other tooth in the circumferential direction with respect to the axis of rotation on an upstream side of the at least one axially recessed upshift initiation tooth with respect to a direction of rotation. With the bicycle chainring according to the fifth aspect, the at least one axially recessed upshift initiation tooth and the axially recessed tooth make the upshifting process smoother.

[0010] According to a sixth aspect of the present invention, the bicycle chainring according to one of the first to fifth aspects is configured such that the at least one axially recessed upshift initiation tooth includes a plurality of axially recessed upshift initiation teeth. In the bicycle chainring according to the sixth aspect, the plurality of axially recessed upshift initiation teeth enables a rapid upshifting process.

[0011] According to a seventh aspect of the present invention, the bicycle chainring according to one of the first to fifth aspects is configured such that the at least one axially recessed upshift initiation tooth includes a first axially recessed upshift initiation tooth and a second axially recessed upshift initiation tooth. The total number of teeth of the bicycle chainring is equal to or greater than 11. With the bicycle chainring according to the seventh aspect, it is possible to perform a dynamically efficient and rapid upshifting process.

[0012] According to an eighth aspect of the present invention, the bicycle chainring according to one of the first to fifth aspects is configured such that the at least one axially recessed upshift initiation tooth includes a first axially recessed upshift initiation tooth, a second axially recessed upshift initiation tooth, and a third axially recessed upshift initiation tooth. The total number of teeth of the bicycle chainring is equal to or greater than 19. With the bicycle chainring according to the eighth aspect, it is possible to perform a dynamically efficient and rapid upshifting process in a medium-sized or larger chainring.

[0013] According to a ninth aspect of the present invention, the bicycle chainring according to one of the first to fifth aspects is configured such that the at least one axially recessed upshift initiation tooth includes a first axially recessed upshift initiation tooth, a second axially recessed upshift initiation tooth, a third axially recessed upshift initiation tooth, and a fourth axially recessed upshift initiation tooth. The total number of teeth of the bicycle chainring is equal to or greater than 25. With the bicycle chainring according to the ninth aspect, it is possible to perform a dynamically efficient and rapid upshifting process in a large or larger chainring.

[0014] According to a tenth aspect of the present invention, the bicycle chainring according to one of the first to fifth aspects is configured such that the at least one axially recessed upshift initiation tooth includes a first axially recessed upshift initiation tooth, a second axially recessed upshift initiation tooth, a third axially recessed upshift initiation tooth, a fourth axially recessed upshift initiation tooth, and a fifth axially recessed upshift initiation tooth. The total number of teeth of the bicycle chainring is equal to or greater than 41. With the bicycle chainring according to the tenth aspect, it is possible to perform a dynamically efficient and rapid upshifting process in a large or larger chainring.

[0015] According to an eleventh aspect of the present invention, a bicycle drivetrain comprises the bicycle sprocket according to any one of the first to tenth aspects and a bicycle chain with an inner connecting link. The inner connecting link includes a first inner connecting end section, a second inner connecting end section, and an inner connecting intermediate section that connects the first inner connecting end section and the second inner connecting end section. With the bicycle drivetrain according to the eleventh aspect, it is possible to further reduce a shock caused by the first chain phase during upshifting while maintaining the same shifting performance.

[0016] According to a twelfth aspect of the present invention, the bicycle drivetrain according to the eleventh aspect is configured such that the first inner connecting end section has a first longitudinally extended edge with respect to a longitudinal centerline of the inner connecting link. The first longitudinally extended edge extends in a first longitudinal direction defined along the longitudinal direction from the second inner connecting end section to the first inner connecting end section. The first longitudinally extended edge is configured to axially support one of the plurality of sprocket teeth of the bicycle sprocket in an engagement state in which one of the sprocket teeth is positioned in an outer connecting space defined between a pair of outer connecting links of the bicycle chain.With the bicycle drivetrain based on the twelfth aspect, it is possible to reduce the shock caused by the first chain phase during upshifting while maintaining the same shifting performance. Furthermore, it is possible to improve the chain retention performance of the bicycle sprocket.

[0017] According to a thirteenth aspect of the present invention, the bicycle drivetrain according to the twelfth aspect is configured such that the second inner linkage end section has a second longitudinally extended edge. This second longitudinally extended edge extends in a second longitudinal direction defined from the first inner linkage end section to the second inner linkage end section along the longitudinal direction. The second longitudinally extended edge is configured to axially support one of the multiple chainring teeth of the bicycle chainring in an engaged state where one of the chainring teeth is positioned in an outer linkage space defined between a pair of outer linkage plates of the bicycle chain. With the bicycle drivetrain according to the thirteenth aspect, it is possible to reduce the shock caused by the first chain phase during upshifting while maintaining the same shifting performance.Furthermore, it is possible to improve the chain retention performance of the bicycle chainring by improving the mounting of the bicycle chain.

[0018] A more comprehensive assessment of the invention and many of its associated advantages is easily achieved, as it is better understood through the following detailed description when considered in conjunction with the accompanying drawings, wherein: Fig. 1 a schematic representation of a bicycle including a bicycle drivetrain; Fig. 2 a side view of a bicycle multi-chainring of the in Fig. 1 is the bicycle drivetrain shown; Fig. 3 a cross-sectional view of the bicycle multiple chainring along line III-III of Fig. 2 is; Fig. 4 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 5 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 6 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 7 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 8 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 9 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 10 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 11 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 12 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 13 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 14 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 15 a side view of a sprocket of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 16 another side view of the in Fig. The bicycle multi-chainwheel shown in the image is; Fig. 17 another side view of the in Fig. 5 shown chain wheel is; Fig. 18 is another side view of the in Fig. 6 shown sprocket; Fig. 19 a partial side view of the in the Fig. 4 and Fig. The 5 depicted sprockets are connected to a bicycle chain; Fig. 20 a partially perspective view of the in Fig. 5 shown chain wheel is; Fig. 21 a partial side view of the in Fig. 5 shown chain wheel is; Fig. 22 a partial side view of a sprocket according to a modification of the in Fig. The sprocket shown in section 21 is; Fig. 23 another partial perspective view of the in Fig. 5 shown chain wheel is; Fig. 24 a partial front view of the in Fig. 5 shown chain wheel is; Fig. 25 a partial front view of a sprocket according to a modification of the in Fig. 5 shown chain wheel is; Fig. 26 a cross-sectional view of the sprocket made of Fig. 21 along line XXVI-XXVI is; Fig. 27 a partial side view of the in Fig. 5 shown chain wheel is; Fig. 28 a partial front view of the in Fig. 4 shown chain wheel is; Fig. 29 a partial side view of the in Fig. 4 shown chain wheel is; Fig. 30 a partially perspective view of the in Fig. 4 shown chain wheel is; Fig. 31 a partial front view of the in Fig. 4 shown chain wheel is; Fig. 32 a partially perspective view of the in Fig. 4 shown chain wheel is; Fig. 33 a side view of an inner connecting link of the bicycle chain of the in Fig. 1 is the bicycle drivetrain shown; Fig. 34 a partially side view of the in Fig. The chain wheel shown in section 4 is connected to the bicycle chain; Fig. 35 a partially side view of the in Fig. The chain wheel shown in section 4 is connected to the bicycle chain; Fig. 36 a cross-sectional view of the sprocket of Fig. 35 along line XXXVI-XXXVI with the bicycle chain; Fig. 37 a partial side view of the in Fig. The sprocket shown in section 12 is; Fig. 38 a partial front view of the in Fig. The sprocket shown in section 12 is; Fig. 39 A side view of a sprocket according to a modification of the one in Fig. The sprocket shown in section 12 is; Fig. 40 a side view of a sprocket according to a modification of the one in Fig. The sprocket shown in section 13 is; Fig. 41 a side view of a sprocket according to a modification of the in Fig. The sprocket shown in section 14 is; Fig. 42 a side view of a sprocket according to a modification of the in Fig. The sprocket shown in section 15 is; and Fig. 43 is a list that specifies a combination of total tooth counts of the sprockets of the bicycle multi-chainring and combinations of total tooth counts of the sprockets of bicycle multi-chainrings according to the modifications.

[0019] Selected embodiments of the present invention will now be described with reference to the accompanying drawings, wherein in the various drawings the same reference numbers denote corresponding or identical elements.

[0020] Initially referring to Fig. 1 comprises a bicycle 10, a bicycle frame BF, and a bicycle drivetrain 11. The bicycle drivetrain 11 includes a crank assembly 2, a hub assembly 4, a bicycle chainring 12, and a bicycle chain C. The bicycle chainring 12 is mounted on the hub assembly 4. The crank assembly 2 includes a crank axle 2A, a right crank arm 2B, a left crank arm 2C, and a front bicycle chainring 2D. The right crank arm 2B and the left crank arm 2C are attached to the crank axle 2A. The front bicycle chainring 2D is attached to at least one of the crank axles 2A and the right crank arm 2B. The bicycle chain C engages with the front chainring 2D and the bicycle chainring 12 to transmit pedaling force from the front chainring 2D to the bicycle chainring 12. In the illustrated version, the crank arrangement 2 includes the front sprocket 2D as a single sprocket.The crank assembly 2 can, however, include a variety of front chainrings. The bicycle multi-chainring 12 is a rear chainring assembly. However, structures of the bicycle multi-chainring 12 can be transferred to the front bicycle chainring.

[0021] In the present application, the following directional terms “front”, “back”, “forward”, “backward”, “left”, “right”, “across”, “upward”, and “downward”, as well as all other similar directional terms, refer to those directions determined by a user (e.g., a rider) sitting on a saddle (not shown) of a bicycle and facing a handlebar (not shown). Accordingly, these terms, as used to describe the bicycle multiple chainring 12, are to be interpreted in relation to the bicycle equipped with the bicycle multiple chainring 12, as used in an upright riding position on a horizontal surface.

[0022] As in Fig. As can be seen in Figure 2, the bicycle multi-chainring 12 has a rotating central axis A1. The bicycle multi-chainring 12 is connected to the bicycle frame BF by the hub assembly 4 ( Fig. 1) The bicycle chainring 12 is rotatably mounted about the central axis A1. It is attached to a chainring support body of the hub assembly 4 by a locking element 4A. The bicycle chainring 12 is configured to engage with the bicycle chain C and, during pedaling, transmit a drive torque F1 between the bicycle chain C and the bicycle chainring 12. During pedaling, the bicycle chainring 12 rotates about the central axis A1 in a rotational direction D11. The rotational direction D11 is defined along a circumferential direction D1 with respect to the central axis A1 of the bicycle chainring 12. A reverse rotational direction D12 is a direction opposite to the rotational direction D11 and is defined along the circumferential direction D1.

[0023] The bicycle multiple chainring 12 comprises a plurality of chainrings SP. The plurality of chainrings SP includes a first chainring SP1 and a second chainring SP2. The plurality of chainrings SP includes third to twelfth chainrings SP3 to SP12. The first to twelfth chainrings SP1 to SP12 can also be referred to as bicycle chainrings SP1 to SP12. Thus, the bicycle drivetrain 11 comprises the bicycle chainring and the bicycle chain C. The total number of chainrings SP is equal to or greater than 10. The total number of chainrings SP is preferably equal to or greater than 11. The total number of chainrings SP is preferably equal to or greater than 12. In this embodiment, the total number of chainrings SP is 12. However, the total number of chainrings SP is not limited to this embodiment and the above ranges.

[0024] In this embodiment, sprocket SP12 is the largest sprocket in the bicycle multi-chainring 12. The third sprocket SP3 is the smallest sprocket in the bicycle multi-chainring 12. The first sprocket SP1 has a first maximum outer diameter DM1. The second sprocket SP2 has a second maximum outer diameter DM2, which is smaller than the first maximum outer diameter DM1. The third sprocket SP3 has a third maximum outer diameter DM3, which is smaller than the second maximum outer diameter DM2. The fourth through twelfth sprockets SP4 through SP12 each have a fourth maximum outer diameter DM4 through a twelfth maximum outer diameter DM12. The third maximum outer diameter DM3 is the smallest among the first through twelfth maximum outer diameters DM1 through DM12. The twelfth maximum outer diameter DM12 is the largest among the first through twelfth maximum outer diameters DM1 through DM12.The dimensional relationship between the sprockets SP1 to SP12 is not limited to this embodiment.

[0025] As in Fig. As shown in Figure 3, the second sprocket SP2 is adjacent to the first sprocket SP1, without any further sprocket being arranged between them in the axial direction D2 with respect to the axis of rotation A1. The axial direction D2 is parallel to the axis of rotation A1. The third sprocket SP3 is adjacent to the second sprocket SP2, without any further sprocket being arranged between them in the axial direction D2. The third, second, first, and fourth through twelfth sprockets SP3, SP2, SP1, and SP4 through SP12 are arranged in this order in the axial direction D2. The sprockets SP1 through SP12 are separate elements. However, at least two of the sprockets SP1 through SP12 can be integrally integrated, at least partially, as a single unit element. The sprockets SP1 through SP12 are made of a metallic material such as titanium or aluminum. However, the materials used for the sprockets SP1 through SP12 are not limited to this embodiment.At least one of the sprockets SP1 to SP12 may be made of a different metallic material or a non-metallic material. At least one of the sprockets SP1 to SP12 may have a composite structure made of a variety of different materials.

[0026] As in Fig. As shown in Figure 4, the first sprocket SP1 comprises a first sprocket body SP1A and a plurality of first sprocket teeth SP1B. The plurality of first sprocket teeth SP1B extends radially outward from the first sprocket body SP1A with respect to the axis of rotation A1 of the bicycle multi-sprocket 12. The first sprocket SP1 can also be referred to as the bicycle sprocket SP1. The first sprocket body SP1A can also be referred to as the sprocket body SP1A. The plurality of first sprocket teeth SP1B can also be referred to as a plurality of sprocket teeth SP1B. Specifically, the sprocket SP1 comprises the sprocket body SP1A and the plurality of sprocket teeth SP1B. The plurality of sprocket teeth SP1B extends radially outward from the sprocket body SP1A with respect to the axis of rotation A1.

[0027] The first sprocket SP1 comprises a plurality of tooth bases SP1C. The tooth base SP1C is positioned between two adjacent sprocket teeth SP1B. The first sprocket SP1 has a tooth base RC1 defined by the plurality of tooth bases SP1C. The total number of teeth of the sprocket SP1 (the total number of the plurality of sprocket teeth SP1B) is equal to or greater than 11. In this embodiment, the total number of teeth of the first sprocket SP1 is 14. However, the total number of the plurality of sprocket teeth SP1B of the first sprocket SP1 is not limited to this embodiment.

[0028] The first chainring SP1 includes at least one first downshift facilitation range FD1, which is configured to facilitate the shifting of the bicycle chain C from the second chainring SP2 ( Fig. 3) to facilitate the shifting of the bicycle chain C from the bicycle chainring SP1 to the smaller chainring SP2 ( Fig. 3) which is adjacent to the bicycle chainring SP1 without another chainring being located between it in the axial direction D2. In this embodiment, the first chainring SP1 includes a plurality of downshift relief areas FD1 and a plurality of upshift relief areas FU1. In this embodiment, the first chainring SP1 includes two downshift relief areas FD1 and two upshift relief areas FU1. However, the total number of downshift relief areas FD1 is not limited to this embodiment. The total number of upshift relief areas FU1 is not limited to this embodiment.

[0029] As in Fig. As shown in Figure 5, the second sprocket SP2 comprises a second sprocket body SP2A and a plurality of second sprocket teeth SP2B. The plurality of second sprocket teeth SP2B extends radially outward from the second sprocket body SP2A with respect to the axis of rotation A1. The second sprocket SP2 can also be referred to as the bicycle sprocket SP2. The second sprocket body SP2A can also be referred to as the sprocket body SP2A. The plurality of second sprocket teeth SP2B can also be referred to as a plurality of sprocket teeth SP2B. The bicycle sprocket SP2 comprises the sprocket body SP2A and the plurality of sprocket teeth SP2B. The plurality of sprocket teeth SP2B extends radially outward from the sprocket body SP2A with respect to the axis of rotation A1.

[0030] The second sprocket SP2 comprises a plurality of tooth bases SP2C. The tooth base SP2C is positioned between two adjacent sprocket teeth SP2B. The second sprocket SP2 has a tooth base RC2, which is defined by the plurality of tooth bases SP2C. The total number of teeth of the bicycle sprocket SP2 (the total number of the plurality of sprocket teeth SP2B) is equal to or greater than 11. In this embodiment, the total number of teeth of the second sprocket SP2 is equal to 12. However, the total number of the plurality of sprocket teeth SP2B of the second sprocket SP2 is not limited to this embodiment.

[0031] The chainring SP2 includes at least one downshift relief area FD2 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP3 to the chainring SP2. The chainring SP2 includes at least one upshift relief area FU2 configured to facilitate the shifting of the bicycle chain C from the chainring SP2 to the smaller chainring SP3. In this embodiment, the second chainring SP2 includes one downshift relief area FD2 and a plurality of upshift relief areas FU2. In this embodiment, the second chainring SP2 includes two upshift relief areas FU2. However, the total number of downshift relief areas FD2 is not limited to this embodiment. The total number of upshift relief areas FU2 is not limited to this embodiment.

[0032] As in Fig. As can be seen in Figure 3, the first sprocket SP1 has a first inner-wheel surface SP1E and a first outer-wheel surface SP1F, which is provided in the axial direction D2 on a side opposite the first inner-wheel surface SP1E. The second sprocket SP2 has a second inner-wheel surface SP2E and a second outer-wheel surface SP2F, which is provided in the axial direction D2 on a side opposite the second inner-wheel surface SP2E. The first outer-wheel surface SP1F and the second outer-wheel surface SP2E are opposite each other in the axial direction D2. The first inner-wheel surface SP1E is configured to face a median plane 10A in a mounted state. Fig. 1) of bicycle 10, with the bicycle chainring SP1 mounted on bicycle 10. The second inner surface of the bicycle SP2E is configured such that, in the assembled state with the bicycle chainring SP1 mounted on bicycle 10, it faces the median plane 10A ( Fig. 1) of bicycle 10 shows.

[0033] The sprocket body SP1A comprises a first axially oriented surface SP1A1 and a second axially oriented surface SP1A2, which are aligned in the axial direction D2 with respect to the rotational center axis A1 of the bicycle sprocket SP1. The second axially oriented surface SP1A2 is located on the opposite side of the first axially oriented surface SP1A1 in the axial direction D2. The first axially oriented surface SP1A1 is configured such that, in the assembled state with the bicycle sprocket SP1 mounted on the bicycle 10, it faces the median plane 10A ( Fig. 1) of bicycle 10 shows.

[0034] As in Fig. As shown in Figure 6, the third sprocket SP3 comprises a third sprocket body SP3A and a plurality of third sprocket teeth SP3B. The plurality of third sprocket teeth SP3B extends radially outward from the third sprocket body SP3A with respect to the axis of rotation A1. The third sprocket SP3 comprises a plurality of tooth bases SP3C. The tooth base SP3C is located between two adjacent sprocket teeth SP3B. The third sprocket SP3 has a tooth base RC3, which is defined by the plurality of tooth bases SP3C. A total number of teeth of the third sprocket SP3 (a total number of the plurality of sprocket teeth SP3B) is 10. However, the total number of the plurality of sprocket teeth SP3B of the third sprocket SP3 is not limited to this embodiment.

[0035] As in Fig. As shown in Figure 7, the fourth sprocket SP4 comprises a fourth sprocket body SP4A and a plurality of fourth sprocket teeth SP4B. The plurality of fourth sprocket teeth SP4B extends radially outward from the fourth sprocket body SP4A with respect to the axis of rotation A1. The fourth sprocket SP4 comprises a plurality of tooth bases SP4C. The tooth base SP4C is located between two adjacent sprocket teeth SP4B. The fourth sprocket SP4 has a tooth base RC4, which is defined by the plurality of tooth bases SP4C. The total number of teeth of the bicycle sprocket SP4 (the total number of the plurality of sprocket teeth SP4B) is equal to or greater than 11. In this embodiment, the total number of teeth of the fourth sprocket SP4 is 16. However, the total number of the plurality of sprocket teeth SP4B of the fourth sprocket SP4 is not limited to this embodiment.

[0036] The chainring SP4 includes at least one downshift relief area FD4 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP1 to the chainring SP4. The chainring SP4 includes at least one upshift relief area FU4 configured to facilitate the shifting of the bicycle chain C from the chainring SP4 to the smaller chainring SP1. In this embodiment, the second chainring SP4 includes a plurality of downshift relief areas FD4 and a plurality of upshift relief areas FU4. In this embodiment, the second chainring SP4 includes two downshift relief areas FD4 and two upshift relief areas FU4. However, the total number of downshift relief areas FD4 is not limited to this embodiment. The total number of upshift relief areas FU4 is not limited to this embodiment.

[0037] As in Fig. As shown in Figure 8, the fifth sprocket SP5 comprises a fifth sprocket body SP5A and a plurality of fifth sprocket teeth SP5B. The plurality of fifth sprocket teeth SP5B extends radially outward from the fifth sprocket body SP5A with respect to the axis of rotation A1. The fifth sprocket SP5 comprises a plurality of tooth bases SP5C. The tooth base SP5C is located between two adjacent sprocket teeth SP5B. The fifth sprocket SP5 has a tooth base RC5, which is defined by the plurality of tooth bases SP5C. The total number of teeth of the bicycle sprocket SP5 (the total number of the plurality of sprocket teeth SP5B) is equal to or greater than 11. In this embodiment, the total number of teeth of the fifth sprocket SP5 is 18. However, the total number of the plurality of sprocket teeth SP5B of the fifth sprocket SP5 is not limited to this embodiment.

[0038] The chainring SP5 includes at least one downshift relief area FD5 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP4 to the chainring SP5. The chainring SP5 includes at least one upshift relief area FU5 configured to facilitate the shifting of the bicycle chain C from the chainring SP5 to the smaller chainring SP4. In this embodiment, the second chainring SP5 includes a plurality of downshift relief areas FD5 and a plurality of upshift relief areas FU5. In this embodiment, the second chainring SP5 includes two downshift relief areas FD5 and two upshift relief areas FU5. However, the total number of downshift relief areas FD5 is not limited to this embodiment. The total number of upshift relief areas FU5 is not limited to this embodiment.

[0039] As in Fig. As shown in Figure 9, the sixth sprocket SP6 comprises a sixth sprocket body SP6A and a plurality of sixth sprocket teeth SP6B. The plurality of sixth sprocket teeth SP6B extends radially outward from the sixth sprocket body SP6A with respect to the axis of rotation A1. The sixth sprocket SP6 comprises a plurality of tooth bases SP6C. The tooth base SP6C is located between two adjacent sprocket teeth SP6B. The sixth sprocket SP6 has a tooth base RC6, which is defined by the plurality of tooth bases SP6C. The total number of teeth of the bicycle sprocket SP6 (the total number of the plurality of sprocket teeth SP6B) is equal to or greater than 19. In this embodiment, the total number of teeth of the sixth sprocket SP6 is equal to 21. However, the total number of the plurality of sprocket teeth SP6B of the sixth sprocket SP6 is not limited to this embodiment.

[0040] The chainring SP6 includes at least one downshift relief area FD6 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP5 to the chainring SP6. The chainring SP6 includes at least one upshift relief area FU6 configured to facilitate the shifting of the bicycle chain C from the chainring SP6 to the smaller chainring SP5. In this embodiment, the second chainring SP6 includes a plurality of downshift relief areas FD6 and a plurality of upshift relief areas FU6. In this embodiment, the second chainring SP6 includes three downshift relief areas FD6 and three upshift relief areas FU6. However, the total number of downshift relief areas FD6 is not limited to this embodiment. The total number of upshift relief areas FU6 is not limited to this embodiment.

[0041] As in Fig. As shown in Figure 10, the seventh sprocket SP7 comprises a seventh sprocket body SP7A and a plurality of seventh sprocket teeth SP7B. The plurality of seventh sprocket teeth SP7B extends radially outward from the seventh sprocket body SP7A with respect to the axis of rotation A1. The seventh sprocket SP7 comprises a plurality of tooth bases SP7C. The tooth base SP7C is positioned between two adjacent sprocket teeth SP7B. The seventh sprocket SP7 has a tooth base RC7, which is defined by the plurality of tooth bases SP7C. The total number of teeth of the bicycle sprocket SP7 (the total number of the plurality of sprocket teeth SP7B) is equal to or greater than 19. In this embodiment, the total number of teeth of the seventh sprocket SP7 is equal to 24. However, the total number of the plurality of sprocket teeth SP7B of the seventh sprocket SP7 is not limited to this embodiment.

[0042] The chainring SP7 includes at least one downshift relief area FD7 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP6 to the chainring SP7. The chainring SP7 includes at least one upshift relief area FU7 configured to facilitate the shifting of the bicycle chain C from the chainring SP7 to the smaller chainring SP6. In this embodiment, the second chainring SP7 includes a plurality of downshift relief areas FD7 and a plurality of upshift relief areas FU7. In this embodiment, the second chainring SP7 includes three downshift relief areas FD7 and three upshift relief areas FU7. However, the total number of downshift relief areas FD7 is not limited to this embodiment. The total number of upshift relief areas FU7 is not limited to this embodiment.

[0043] As in Fig. As shown in Figure 11, the eighth sprocket SP8 comprises an eighth sprocket body SP8A and a plurality of eighth sprocket teeth SP8B. The plurality of eighth sprocket teeth SP8B extends radially outward from the eighth sprocket body SP8A with respect to the axis of rotation A1. The eighth sprocket SP8 comprises a plurality of tooth bases SP8C. The tooth base SP8C is located between two adjacent sprocket teeth SP8B. The eighth sprocket SP8 has a tooth base RC8, which is defined by the plurality of tooth bases SP8C. The total number of teeth of the bicycle sprocket SP8 (the total number of the plurality of sprocket teeth SP8B) is equal to or greater than 25. In this embodiment, the total number of teeth of the eighth sprocket SP8 is 28. However, the total number of the plurality of sprocket teeth SP8B of the eighth sprocket SP8 is not limited to this embodiment.

[0044] The chainring SP8 includes at least one downshift relief area FD8 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP7 to the chainring SP8. The chainring SP8 includes at least one upshift relief area FU8 configured to facilitate the shifting of the bicycle chain C from the chainring SP8 to the smaller chainring SP7. In this embodiment, the second chainring SP8 includes a plurality of downshift relief areas FD8 and a plurality of upshift relief areas FU8. In this embodiment, the second chainring SP8 includes four downshift relief areas FD8 and four upshift relief areas FU8. However, the total number of downshift relief areas FD8 is not limited to this embodiment. The total number of upshift relief areas FU8 is not limited to this embodiment.

[0045] As in Fig. As shown in Figure 12, the ninth sprocket SP9 comprises a ninth sprocket body SP9A and a plurality of ninth sprocket teeth SP9B. The plurality of ninth sprocket teeth SP9B extends radially outward from the ninth sprocket body SP9A with respect to the axis of rotation A1. The ninth sprocket SP9 can also be referred to as the sprocket SP9. The ninth sprocket body SP9A can also be referred to as the sprocket body SP9A. The plurality of ninth sprocket teeth SP9B can also be referred to as the sprocket teeth SP9B. Thus, the bicycle sprocket SP9 comprises the sprocket body SP9A and the plurality of sprocket teeth SP9B. The plurality of sprocket teeth SP9B extends radially outward from the sprocket body SP9A with respect to the axis of rotation A1.

[0046] The ninth sprocket SP9 comprises a plurality of tooth bases SP9C. The tooth base SP9C is positioned between two adjacent sprocket teeth SP9B. The ninth sprocket SP9 has a tooth base circle RC9, which is defined by the plurality of tooth bases SP9C. The total number of teeth of the bicycle sprocket SP9 (the total number of teeth in the plurality of sprocket teeth SP9B) is equal to or greater than 25. In this embodiment, the total number of teeth of the ninth sprocket SP9 is 32. However, the total number of teeth in the plurality of sprocket teeth SP9B of the ninth sprocket SP9 is not limited to this embodiment.

[0047] The bicycle chainring SP9 comprises at least one shift-facilitation area FU9 configured to facilitate the shifting of the bicycle chain C from the bicycle chainring SP9 to the smaller chainring SP8, which is axially adjacent to the bicycle chainring SP9 in the direction D2 without any further bicycle chainring in between. In this embodiment, the bicycle chainring SP9 comprises a plurality of shift-facilitation areas FU9. In this embodiment, the bicycle chainring SP9 comprises four shift-facilitation areas FU9. However, the total number of shift-facilitation areas FU9 is not limited to this embodiment.

[0048] The bicycle chainring SP9 further comprises at least one downshift facilitation area FD9 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP8 to the bicycle chainring SP9. In this embodiment, the bicycle chainring SP9 comprises a plurality of downshift facilitation areas FD9. In this embodiment, the bicycle chainring SP9 comprises four downshift facilitation areas FD9. However, the total number of downshift facilitation areas FD9 is not limited to this embodiment.

[0049] As in Fig. As shown in Figure 13, the tenth sprocket SP10 comprises a tenth sprocket body SP10A and a plurality of tenth sprocket teeth SP10B. The plurality of tenth sprocket teeth SP10B extends radially outward from the tenth sprocket body SP10A with respect to the axis of rotation A1. The tenth sprocket SP10 comprises a plurality of tooth bases SP10C. The tooth base SP10C is located between two adjacent sprocket teeth SP10B. The tenth sprocket SP10 has a tooth base RC10, which is defined by the plurality of tooth bases SP10C. The total number of teeth of the bicycle sprocket SP10 (the total number of the plurality of sprocket teeth SP10B) is equal to or greater than 25. In this embodiment, the total number of teeth of the tenth sprocket SP10 is 36. However, the total number of the plurality of sprocket teeth SP10B of the tenth sprocket SP10 is not limited to this embodiment.

[0050] The chainring SP10 includes at least one downshift relief area FD10 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP9 to the chainring SP10. The chainring SP10 includes at least one upshift relief area FU10 configured to facilitate the shifting of the bicycle chain C from the chainring SP10 to the smaller chainring SP9. In this embodiment, the second chainring SP10 includes a plurality of downshift relief areas FD10 and a plurality of upshift relief areas FU10. In this embodiment, the second chainring SP10 includes four downshift relief areas FD10 and four upshift relief areas FU10. However, the total number of downshift relief areas FD10 is not limited to this embodiment. The total number of upshift relief areas FU10 is not limited to this embodiment.

[0051] As in Fig. As shown in Figure 14, the eleventh sprocket SP11 comprises an eleventh sprocket body SP11A and a plurality of eleventh sprocket teeth SP11B. The plurality of eleventh sprocket teeth SP11B extends radially outward from the eleventh sprocket body SP11A with respect to the axis of rotation A1. The eleventh sprocket SP11 comprises a plurality of tooth bases SP11C. The tooth base SP11C is located between two adjacent sprocket teeth SP11B. The eleventh sprocket SP11 has a tooth base RC11, which is defined by the plurality of tooth bases SP11C. The total number of teeth of the bicycle sprocket SP11 (the total number of the plurality of sprocket teeth SP11B) is equal to or greater than 25. In this embodiment, the total number of teeth of the eleventh sprocket SP11 is 40. However, the total number of the plurality of sprocket teeth SP11B of the eleventh sprocket SP11 is not limited to this embodiment.

[0052] The chainring SP11 includes at least one downshift relief area FD11 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP10 to the chainring SP11. The chainring SP11 includes at least one upshift relief area FU11 configured to facilitate the shifting of the bicycle chain C from the chainring SP11 to the smaller chainring SP10. In this embodiment, the second chainring SP11 includes a plurality of downshift relief areas FD11 and a plurality of upshift relief areas FU11. In this embodiment, the second chainring SP11 includes four downshift relief areas FD11 and four upshift relief areas FU11. However, the total number of downshift relief areas FD11 is not limited to this embodiment. The total number of upshift relief areas FU11 is not limited to this embodiment.

[0053] As in Fig. As shown in Figure 15, the twelfth sprocket SP12 comprises a twelfth sprocket body SP12A and a plurality of twelfth sprocket teeth SP12B. The plurality of twelfth sprocket teeth SP12B extends radially outward from the twelfth sprocket body SP12A with respect to the axis of rotation A1. The twelfth sprocket SP12 comprises a plurality of tooth bases SP12C. The tooth base SP12C is located between two adjacent sprocket teeth SP12B. The twelfth sprocket SP12 has a tooth base RC12, which is defined by the plurality of tooth bases SP12C. The total number of teeth of the bicycle sprocket SP12 (the total number of the plurality of sprocket teeth SP12B) is equal to or greater than 41. In this embodiment, the total number of teeth of the twelfth sprocket SP12 is 45. However, the total number of the plurality of sprocket teeth SP12B of the twelfth sprocket SP12 is not limited to this embodiment.

[0054] The chainring SP12 includes at least one downshift relief area FD12 configured to facilitate the shifting of the bicycle chain C from the smaller chainring SP11 to the chainring SP12. The chainring SP12 includes at least one upshift relief area FU12 configured to facilitate the shifting of the bicycle chain C from the chainring SP12 to the smaller chainring SP11. In this embodiment, the second chainring SP12 includes a plurality of downshift relief areas FD12 and a plurality of upshift relief areas FU12. In this embodiment, the second chainring SP12 includes five downshift relief areas FD12 and five upshift relief areas FU12. However, the total number of downshift relief areas FD12 is not limited to this embodiment. The total number of upshift relief areas FU12 is not limited to this embodiment.

[0055] As in Fig. As shown in Figure 16, the bicycle multiple chainring 12 comprises a chainring carrier 14. The chainring carrier 14 includes a hub engagement part 16 and a plurality of chainring mounting arms 18. The hub engagement part 16 is configured to engage with a chainring carrier body 4B of the hub assembly 4, with the plurality of chainring mounting arms 18 extending radially outward from the hub engagement part 16. In this embodiment, the total number of chainring carriers 18 is 6. However, the total number of chainring mounting arms 18 is not limited to this embodiment.

[0056] As in Fig. As can be seen in Figure 3, the multitude of sprockets SP6, SP7 and SP9 to SP11 are attached to the multitude of sprocket mounting arms 18. The bicycle sprocket SP6 is equipped with a multitude of mounting elements F6 ( Fig. 16) attached to the multitude of sprocket mounting arms 18. The SP7 sprocket is attached to a multitude of mounting elements F7 ( Fig. 16) attached to the plurality of sprocket mounting arms 18. The sprocket SP9 is attached to the plurality of sprocket mounting arms 18 by a plurality of fastening elements F9 ( Fig. 16). The SP10 sprocket is attached to the multiple sprocket mounting arms 18 by a multitude of fastening elements F10 ( Fig. 16). The SP11 sprocket is equipped with a variety of F11 fasteners ( Fig. 16) attached to the multiple sprocket mounting arms 18. The sprocket SP12 is attached to the sprocket SP11 by a multiple of fasteners F12 ( Fig. 16).

[0057] Sprocket SP5 is attached to sprocket SP6 using a variety of fasteners F6. A variety of spacers SC6 are provided between sprockets SP5 and SP6. Sprocket SP8 is attached to sprocket SP9 using a variety of fasteners F9. A variety of spacers SC9 are provided between sprockets SP8 and SP9. Sprocket SP12 is attached to sprocket SP11 using a variety of fasteners F12. A variety of spacers SC12 are provided between sprockets SP11 and SP12.

[0058] The hub engagement part 16 includes an internal hub toothing 19 configured to engage with a plurality of external teeth (not shown) of the hub assembly 4, the internal hub toothing 19 comprising a first internal hub toothing 20 and a second internal hub toothing 22. The first internal hub toothing 20 is spaced axially D2 from the second internal hub toothing 22 to define, in this embodiment, an annular recess 24 in axial direction D2 between the first internal hub toothing 20 and the second internal hub toothing 22. The first internal hub toothing 20 may be connected to the second internal hub toothing 22.

[0059] The first hub internal toothing 20 includes a plurality of first internal toothing teeth 28 configured to engage with the plurality of external toothing teeth (not shown) of the hub arrangement 4, and the second hub internal toothing 22 includes a plurality of second internal toothing teeth 30 configured to engage with the plurality of external toothing teeth (not shown) of the hub arrangement 4.

[0060] As in Fig. As can be seen in Figure 7, the SP4 sprocket incorporates an internal toothing SP4S. The internal toothing SP4S incorporates a multitude of internal teeth SP4H configured to engage with the multitude of external teeth (not shown) of the hub assembly 4 ( Fig. 3) As in Fig. As can be seen in Figure 3, the chainring SP4 is held in an axial direction D2 between the hub engagement part 16 of the chainring carrier 14 and the locking element 4A of the hub assembly 4 in a state in which the bicycle multiple chainring 12 is mounted on the hub assembly 4.

[0061] As in Fig. As can be seen in Figure 4, the sprocket SP1 incorporates an internal toothing SP1S. The internal toothing SP1S incorporates a plurality of internal teeth SP1H configured to engage with the plurality of external teeth (not shown) of the hub assembly 4 ( Fig. 3) As in Fig. As can be seen in Figure 3, in a state in which the bicycle multiple chainring 12 is mounted on the hub assembly 4, the chainring SP1 is held in axial direction D2 between the hub engagement part 16 of the chainring carrier 14 and the locking element 4A of the hub assembly 4.

[0062] As in Fig. As can be seen in Figure 17, the SP2 sprocket incorporates an internal toothing SP2S. The internal toothing SP2S incorporates a plurality of internal teeth SP2H configured to engage with the plurality of external teeth (not shown) of the hub assembly 4 ( Fig. 3) As in Fig. Figure 3 shows that the bicycle multiple chainring 12 is mounted on the hub assembly 4, and the chainring SP2 is held in axial direction D2 between the hub engagement part 16 of the chainring carrier 14 and the locking element 4A of the hub assembly 4.

[0063] As in Fig. As shown in Figure 18, the SP3 sprocket incorporates a SP3F torque transmission profile. The SP3F torque transmission profile includes a multitude of SP3G external teeth configured to engage with the SP2 sprocket and transmit the drive torque F1. As shown in Figure 18, the SP3 sprocket incorporates a torque transmission profile SP3F. Fig. As can be seen in Figure 5, the SP2 sprocket incorporates a SP2O torque transmission profile. The SP2O torque transmission profile includes a multitude of additional internal teeth, SP2G, configured to engage with the multitude of external teeth, SP3G, of the SP3 sprocket and transmit the drive torque, F1.

[0064] As in Fig. As shown in Figure 5, the plurality of second sprocket teeth SP2B includes at least one chain deflection limiting tooth SP2L. In this embodiment, the plurality of second sprocket teeth SP2B includes a chain deflection limiting tooth SP2L. In particular, the second sprocket SP2 with twelve second sprocket teeth SP2B includes a chain deflection limiting tooth SP2L. However, the plurality of second sprocket teeth SP2B includes a further chain deflection limiting tooth instead of or in addition to the chain deflection limiting tooth SP2L.

[0065] As in Fig. As shown in Figure 19, the at least one chain bending limiting tooth SP2L has a chain bending limiting surface SP2L1. The chain bending limiting surface SP2L1 is configured to support the inner connecting link C1 of the bicycle chain C in axial direction D2 with respect to the axis of rotation A1 in a chain bending condition where the bicycle chain C is inclined from the at least one chain bending limiting tooth SP2L to the first bicycle sprocket SP1, in order to prevent one (e.g. SP1R) of the plurality of first sprocket teeth SP1B from engaging in an outer connecting space C2A provided between an opposing pair of outer connecting links C2 of the bicycle chain C.The chain bending limiting surface SP2L1 contacts the inner connecting tab C1 to limit axial movement of the opposite pair of outer connecting tabs C2 during a downshifting operation in which the bicycle chain C is moved by a derailleur from the second chainring SP2 to the first chainring SP1 (not shown).

[0066] As in Fig. As can be seen in Figure 20, the chain bending limiting surface SP2L1 is located in the second outer surface of the bicycle, SP2F. The at least one chain bending limiting tooth SP2L has a chamfered section SP2L2, which is located in the second outer surface of the bicycle, SP2F.

[0067] As in Fig. As can be seen in Figure 21, the chain bending limiting surface SP2L1 extends at least partially in a radial direction with respect to the axis of rotation A1. The chain bending limiting surface SP2L1 is located radially inside the chamfered section SP2L2 with respect to the axis of rotation A1. The chain bending limiting surface SP2L1 is also located radially outward from the tooth root circle RC2 with respect to the axis of rotation A1.

[0068] The chain deflection limiting surface SP2L1 is arranged in a radial tooth region TR with respect to the axis of rotation A1. The radial tooth region TR has a radially outermost end TR1 and a radially innermost end TR2 with respect to the axis of rotation A1. The radial tooth region TR is located radially outside the tooth root circle RC2. The radially outermost end TR1 of the radial tooth region TR is located radially outside the radially innermost end TR2 of the radial tooth region TR.

[0069] A first radial distance RD1, defined with respect to the axis of rotation A1 between the radially outermost end TR1 of the radial tooth section TR and the tooth base circle RC2 of the second sprocket SP2, is 4.5 mm. A second radial distance RD2, defined with respect to the axis of rotation A1 between the radially innermost end TR2 of the radial tooth section TR and the tooth base circle RC2 of the second sprocket SP2, is 2.5 mm. The first radial distance RD1 is defined radially outward from the tooth base circle RC2 to the radially outermost end TR1 of the radial tooth section TR. The second radial distance RD2 is defined radially outward from the tooth base circle RC2 to the radially innermost end TR2 of the radial tooth section TR. However, the radial tooth section TR is not limited to this embodiment.

[0070] In this embodiment, the chain bending limiting surface SP2L1 does not reach a tooth tip SP2L3 of the at least one chain bending limiting tooth SP2L. The chamfered section SP2L2 is provided between the chain bending limiting surface SP2L1 and the tooth tip SP2L3 of the chain bending limiting tooth SP2L when viewed along the axis of rotation A1. As in Fig. As can be seen in Figure 22, the chain bending limiting surface SP2L1 can reach the tooth tip SP2L3 of the at least one chain bending limiting tooth SP2L. In this modification, the chamfered section SP2L2 of the chain bending limiting tooth SP2L is omitted.

[0071] As in the Fig. 20 and Fig. As shown in Figure 21, the chain bending limiting tooth SP2L comprises an upstream surface SP2L6 and a downstream surface SP2L7. The upstream surface SP2L6 is located on an upstream side of the chain bending limiting surface SP2L1 in the direction of rotation D11. The downstream surface SP2L7 is located on a downstream side of the chain bending limiting surface SP2L1 in the direction of rotation D11. The upstream surface SP2L6 is coupled to the chain bending limiting surface SP2L1 and the chamfered section SP2L2. The downstream surface SP2L7 is coupled to the chain bending limiting surface SP2L1 and the chamfered section SP2L2.

[0072] As in Fig. As shown in Figure 23, the at least one chain bend limiting tooth SP2L has an additional chamfered section SP2L4, which is located in the second inner surface SP2E. However, the additional chamfered section SP2L4 can be omitted in the chain bend limiting tooth SP2L. The chain bend limiting tooth SP2L includes an additional downstream surface SP2L8. The additional downstream surface SP2L8 is located on a downstream side of the chain bend limiting tooth SP2L in the direction of rotation D11. The additional downstream surface SP2L8 is coupled to the additional chamfered section SP2L4.

[0073] As in Fig. As shown in Figure 24, the chamfered section SP2L2 is configured such that the tooth tip SP2L3 of the at least one chain bending limiting tooth SP2L is located at least partially closer to the second inner bicycle-side surface SP2E than to the second outer bicycle-side surface SP2F in the axial direction D2. In this embodiment, the tooth tip SP2L3 of the chain bending limiting tooth SP2L is located partially closer to the second inner bicycle-side surface SP2E than to the second outer bicycle-side surface SP2F in the axial direction D2. The tooth tip SP2L3 includes an axial center point CP1, which is provided at a circumferential end of the tooth tip SP2L3. A first distance DS1 is defined in the axial direction D2 between the axial center point CP1 and a surface SP2A1. A second distance DS2 is defined in the axial direction D2 between the axial center point CP1 and a surface SP2A2.Surface SP2A1 is provided in the axial direction D2 on a back side of surface PS2A2. The first distance DS1 is smaller than the second distance DS2. The chamfered section SP2L2 extends from the tooth tip SP2L3 of the at least one chain bending limiting tooth SP2L to the chain bending limiting surface SP2L1.

[0074] An axial distance AD ​​is defined between the chain deflection limiting surface SP2L1 and the surface SP2A2 of the second sprocket body SP2A in the second bicycle-side surface SP2F with respect to the rotatable central axis A1. The axial distance AD ​​ranges from 0 mm to 0.3 mm. In this embodiment, the axial distance AD ​​is 0.1 mm. However, the axial distance AD ​​is not limited to this embodiment and the range described above.

[0075] The chain deflection limiting surface SP2L1 is offset in axial direction D2 from the surface SP2A2 of the second sprocket body SP2A towards the second inner bicycle surface SP2E. As shown in Fig. However, as can be seen in Figure 25, the chain bending limiting surface SP2L1 can be offset in axial direction D2 from the surface SP2A2 of the second sprocket body SP2A away from the second bicycle-side surface SP2E.

[0076] As in Fig. As shown in Figure 26, the second sprocket body SP2A has an axially recessed section SP2A3, which is recessed axially with respect to the axis of rotation A1. The axially recessed section SP2A3 is recessed in the axial direction D2. The axially recessed section SP2A3 is located in the second outer surface SP2F of the bicycle. The axially recessed section SP2A3 is located radially inside the chain bending limiting surface SP2L1 with respect to the axis of rotation A1.

[0077] As in Fig. As shown in Figure 27, the at least one chain deflection limiting tooth SP2L has a tooth radial height RH1 relative to the axis of rotation A1. The tooth radial height RH1 of the at least one chain deflection limiting tooth SP2L is greater than the radial heights RH2 of the other teeth of the plurality of second sprocket teeth SP2B. The tooth radial height RH1 is defined radially outward from the tooth base circle RC2 to the tooth tip SP2L3 of the chain deflection limiting tooth SP2L. The radial heights RH2 are defined radially outward from the tooth base circle RC2 to the tooth tips SP2M3 of the second sprocket teeth SP2M of the second sprocket teeth SP2B.

[0078] In this embodiment, for example, the difference between the tooth radial height RH1 and the radial heights RH2 of the second sprocket teeth SP2M is 0.5 mm. However, the difference between the tooth radial height RH1 and the radial heights RH2 of the second sprocket teeth SP2M is not limited to this embodiment.

[0079] As in Fig. As shown in Figure 4, the plurality of sprocket teeth SP1B includes a plurality of chain deflection limiting teeth SP1L. In this embodiment, the first bicycle sprocket SP1 comprises fourteen sprocket teeth SP1B, including two chain deflection limiting teeth SP1L. As shown in Figure 4, the plurality of sprocket teeth SP1B includes a plurality of chain deflection limiting teeth SP1L. Fig. As shown in Figure 6, the multiple sprocket teeth SP3B include a chain deflection limiting tooth SP3L. In this embodiment, the third sprocket SP3 comprises ten sprocket teeth SP3B, including a chain deflection limiting tooth SP3L. As shown in Figure 6, the multiple sprocket teeth SP3B include a chain deflection limiting tooth SP3L. Fig. As can be seen in Figure 7, the plurality of sprocket teeth SP4B includes a plurality of chain deflection limiting teeth SP4L. In this embodiment, the fourth sprocket SP4 comprises sixteen sprocket teeth SP4B, including two chain deflection limiting teeth SP4L. The chain deflection limiting teeth SP1L, SP3L, and SP4L have essentially the same structure as the chain deflection limiting tooth SP2L of the second sprocket SP2. The chain deflection limiting tooth SP3L has essentially the same structure as that shown in Figure 7. Fig. The 22nd modification shown is therefore not described in detail here for the sake of brevity.

[0080] As in Fig. As shown in Figure 4, the multiple first sprocket teeth SP1B include a first downshift initiation tooth SP1N and a first axially recessed tooth SP1R, which is axially offset with respect to the rotational center axis A1. The first downshift initiation tooth SP1N is configured to initially engage the bicycle chain C in a downshift operation, where the bicycle chain C is shifted from the smaller sprocket SP2 to the first sprocket SP1. The first axially recessed tooth SP1R is configured to reduce interference between the second sprocket SP2 and the bicycle chain C during the downshift operation.

[0081] The first axially recessed tooth SP1R abuts the first downshift initiation tooth SP1N on a downstream side of the direction of rotation D11 without any further tooth intervening. The first downshift initiation tooth SP1N and the first axially recessed tooth SP1R are arranged in the at least one first downshift facilitation area FD1. In this embodiment, the plurality of first sprocket teeth SP1B includes a plurality of first downshift initiation teeth SP1N and a plurality of first axially recessed teeth SP1R. However, the total number of first downshift initiation teeth SP1N is not limited to this embodiment. The total number of first axially recessed teeth SP1R is not limited to this embodiment.

[0082] As in Fig. As shown in Figure 28, the first axially recessed tooth SP1R in this embodiment has a recess SP1R1, which is provided on the first outer surface of the bicycle SP1F. The recess SP1R1 extends in the axial direction D2 from the first outer surface of the bicycle SP1F to the first inner surface of the bicycle SP1E.

[0083] As in Fig. As can be seen in Figure 19, at least one chain bending limiting tooth SP2L is located on a downstream side of the direction of rotation D11, viewed from the axial direction D2 with respect to the axis of rotation A1, without any further tooth in between, next to the first axially recessed tooth SP1R. The chain bending limiting surface SP2L1 is configured to support the inner connecting link C1 of the bicycle chain C in the axial direction D2 in a chain bending condition where the bicycle chain C is inclined from the chain bending limiting tooth SP2L to the first axially recessed tooth SP1R, in order to prevent the first axially recessed tooth SP1R from engaging in the outer connecting space C2A, which is provided between the opposite pair of outer connecting links C2 of the bicycle chain C.

[0084] As in Fig. As shown in Figure 4, the plurality of sprocket teeth SP1B includes at least one axially recessed upshift initiation tooth SP1U, which is recessed axially with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP1U includes a plurality of axially recessed upshift initiation teeth SP1U. In particular, the at least one axially recessed upshift initiation tooth SP1U includes a first axially recessed upshift initiation tooth SP1UA and a second axially recessed upshift initiation tooth SP1UB. However, the total number of axially recessed upshift initiation teeth SP1U is not limited to this embodiment.

[0085] The at least one axially recessed upshift initiation tooth SP1U is arranged in the at least one upshift facilitation area FU1. The at least one axially recessed upshift initiation tooth SP1U is configured to release the inner connecting link C1 of the bicycle chain C from the at least one axially recessed upshift initiation tooth SP1U during an upshift operation in which the bicycle chain C shifts from the bicycle chainring SP1 to the smaller chainring SP2.

[0086] The axially recessed upshift initiation tooth SP1U is configured to first disengage the bicycle chain C from the first chainring SP1 at the axially recessed upshift initiation tooth SP1U during the upshifting process, in which the bicycle chain C is shifted from the first chainring SP1 to the smaller chainring SP2. The axially recessed upshift initiation tooth SP1U is configured to first disengage from the opposite pair of inner connecting plates C1 of the bicycle chain C during the upshifting process. The axially recessed upshift initiation tooth SP1U is not configured to first disengage from the opposite pair of outer connecting plates C2 of the bicycle chain C during the upshifting process, because the axial width of the opposite pair of outer connecting plates C2 is greater than the axial width of the opposite pair of inner connecting plates C1.

[0087] The plurality of sprocket teeth SP1B includes a last chain-shifting tooth SP1T, which is adjacent to the at least one axially recessed upshift initiation tooth SP1U. The last chain-shifting tooth SP1T is located on a downstream side of the at least one axially recessed upshift initiation tooth SP1U with respect to the direction of rotation D11. The last chain-shifting tooth SP1T is configured to be the last to disengage from the outer connecting link C2 of the bicycle chain C during the upshifting process. In this embodiment, the plurality of sprocket teeth SP1B includes the last chain-shifting teeth SP1T. The last chain-shifting tooth SP1T is located in the upshift facilitation area FU1.

[0088] The plurality of sprocket teeth SP1B includes, on an upstream side of the at least one axially recessed upshift initiation tooth SP1U, adjacent to the at least one axially recessed upshift initiation tooth SP1U with respect to the direction of rotation D11 and without any other tooth in the circumferential direction D1 with respect to the axis of rotation A1, at least one axially recessed tooth SP1P. In this embodiment, the plurality of sprocket teeth SP1B includes a plurality of axially recessed teeth SP1P. However, the total number of axially recessed teeth SP1P is not limited to this embodiment.

[0089] The axially recessed tooth SP1P is configured to reduce interference between the first chainring SP1 and the bicycle chain C during the upshifting process, when the bicycle chain C is moved from the first chainring SP1 to the smaller chainring SP2. The axially recessed tooth SP1P is located in the upshifting facilitation area FU1.

[0090] As in the Fig. 29 and Fig. As shown in Figure 30, the at least one axially recessed upshift initiation tooth SP1U comprises a driving surface SP1U1, a non-driving surface SP1U2, and a tooth tip section SP1U3. The driving surface SP1U1 includes a tooth tip end E11 on the driving surface side. The non-driving surface SP1U2 includes a tooth tip end E12 on the non-driving surface side. The tooth tip section SP1U3 connects the tooth tip end E11 on the driving surface side and the tooth tip end E12 on the non-driving surface side. The tooth tip end E11 on the driving surface side is located at a radially outermost end of the driving surface SP1U1. The tooth tip end E12 on the non-driving surface side is located at a radially outermost end of the non-driving surface SP1U2.

[0091] As in Fig. As shown in Figure 29, the non-riding surface SP1U2 extends from the non-riding surface tooth tip end E12 in the circumferential direction D1 with respect to the axis of rotation A1. The non-riding surface SP1U2 includes a non-riding surface projection SP1U4, which is located radially inside the non-riding surface tooth tip end E12 with respect to the axis of rotation A1. The non-riding surface projection SP1U4 has a projection tip SP1U5. The projection tip SP1U5 is located radially inside the non-riding surface tooth tip end E12 with respect to the axis of rotation A1. The projection tip SP1U5 is located radially outside the tooth base circle RC1 of the bicycle chainring SP1 with respect to the axis of rotation A1.

[0092] As in the Fig. 31 and Fig. As can be seen in Figure 32, the projection tip SP1U5 is arranged in the axial direction D2 closer to the second axially oriented surface SP1A2 than the non-tracking-side tooth tip end E12, so that a guide chamfer SP1U6 extends from the projection tip SP1U5 to the first axially oriented surface SP1A1. The guide chamfer SP1U6 is provided on the non-tracking-surface projection SP1U4 and is located in the axial direction D2 closer to the first axially oriented surface SP1A1 than to the second axially oriented surface SP1A2.

[0093] As in Fig. As shown in Figure 33, the bicycle chain C comprises an inner connecting link C1 and an outer connecting link C2. The inner connecting link C1 includes a first inner connecting end section C11, a second inner connecting end section C12, and an inner connecting intermediate section C13, which connects the first inner connecting end section C11 and the second inner connecting end section C12. The first inner connecting end section C11 has a first longitudinally extended edge C11A in the longitudinal direction D3 with respect to a longitudinal centerline CL1 of the inner connecting link C1. The first longitudinally extended edge C11A extends in a first longitudinal direction D31, which is defined along the longitudinal direction D3 from the second inner connecting end section C12 to the first inner connecting end section C11. The first inner connecting end section C11 includes a first inner connecting opening C11B with a first central axis CA11.The second internal connection end section C12 includes a second internal connection opening C12B with a second central axis CA12. The longitudinal centerline CL1 intersects with the first central axis CA11 and the second central axis CA12. The longitudinal direction D3 is parallel to the longitudinal centerline CL1.

[0094] The second internal connection end section C12 has a second longitudinally extended edge C12A in the longitudinal direction D3. The second longitudinally extended edge C12A extends in a second longitudinal direction D32, which is defined along the longitudinal direction D3 from the first internal connection end section to the second internal connection end section C12.

[0095] As in Fig. As shown in Figure 34, the first longitudinally extended edge C11A is configured to carry one of the multiple sprocket teeth SP1B of the bicycle sprocket SP1 in the axial direction D2 when one of the multiple sprocket teeth SP1B is positioned in the outer connection space C2A, which is defined between the pair of outer connecting links C2 of the bicycle chain C. The second longitudinally extended edge C12A is configured to carry one of the multiple sprocket teeth SP1B of the bicycle sprocket SP1 in the axial direction D2 when one of the multiple sprocket teeth SP1B is positioned in the outer connection space C2A, which is defined between the pair of outer connecting links C2 of the bicycle chain C.

[0096] As in the Fig. 35 and Fig. As shown in Figure 36, the guide chamfer SP1U6 of the non-riding surface projection SP1U4 makes contact with the first longitudinally extended edge C11A of the inner connecting link C1 of the bicycle chain C during the upshifting process, in which the bicycle chain C is shifted from the bicycle chainring SP1 to the smaller chainring SP2. Thus, the non-riding surface projection SP1U4 guides the bicycle chain C with the guide chamfer SP1U6 such that the axially recessed upshifting initiation tooth SP1U (SP1UA) enters the outer connecting space C2A of the opposite pair of outer connecting links C2 during the upshifting process. The axially recessed upshifting initiation tooth SP1U (SP1UB) initially disengages from the opposite pair of inner connecting links C1 of the bicycle chain C during the upshifting process.

[0097] The teeth of other sprockets may incorporate the structure of the axially recessed high-shift entry tooth SP1U of the SP1 sprocket. For example, as in Fig. As can be seen in Figure 5, the plurality of sprocket teeth SP2B includes at least one axially recessed upshift initiation tooth SP2U, which is axially recessed with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP2U comprises a plurality of axially recessed upshift initiation teeth SP2U. In particular, the at least one axially recessed upshift initiation tooth SP2U comprises a first axially recessed upshift initiation tooth SP2UA and a second axially recessed upshift initiation tooth SP2UB. However, the total number of axially recessed upshift initiation teeth SP2U is not limited to this embodiment.

[0098] As in Fig. As shown in Figure 7, the plurality of sprocket teeth SP4B includes at least one axially recessed upshift initiation tooth SP4U, which is recessed axially with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP4U includes a plurality of axially recessed upshift initiation teeth SP4U. In particular, the at least one axially recessed upshift initiation tooth SP4U includes a first axially recessed upshift initiation tooth SP4UA and a second axially recessed upshift initiation tooth SP4UB. However, the total number of axially recessed upshift initiation teeth SP4U is not limited to this embodiment.

[0099] As in Fig. As shown in Figure 8, the plurality of sprocket teeth SP5B includes at least one axially recessed upshift initiation tooth SP5U, which is axially recessed with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP5U includes a plurality of axially recessed upshift initiation teeth SP5U. In particular, the at least one axially recessed upshift initiation tooth SP5U includes a first axially recessed upshift initiation tooth SP5UA and a second axially recessed upshift initiation tooth SP5UB. However, the total number of axially recessed upshift initiation teeth SP5U is not limited to this embodiment.

[0100] As in Fig. As shown in Figure 9, the plurality of sprocket teeth SP6B includes at least one axially recessed upshift initiation tooth SP6U, which is axially recessed with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP6U includes a plurality of axially recessed upshift initiation teeth SP6U. In particular, the at least one axially recessed upshift initiation tooth SP6U includes a first axially recessed upshift initiation tooth SP6UA, a second axially recessed upshift initiation tooth SP6UB, and a third axially recessed upshift initiation tooth SP6UC. However, the total number of axially recessed upshift initiation teeth SP6U is not limited to this embodiment.

[0101] As in Fig. As shown in Figure 10, the plurality of sprocket teeth SP7B includes at least one axially recessed upshift initiation tooth SP7U, which is axially recessed with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP7U includes a plurality of axially recessed upshift initiation teeth SP7U. In particular, the at least one axially recessed upshift initiation tooth SP7U includes a first axially recessed upshift initiation tooth SP7UA, a second axially recessed upshift initiation tooth SP7UB, and a third axially recessed upshift initiation tooth SP7UC. However, the total number of axially recessed upshift initiation teeth SP7U is not limited to this embodiment.

[0102] As in Fig. As shown in Figure 11, the plurality of sprocket teeth SP8B includes at least one axially recessed upshift initiation tooth SP8U, which is axially recessed with respect to the axis of rotation A1. In this embodiment, the at least one axially recessed upshift initiation tooth SP8U includes a plurality of axially recessed upshift initiation teeth SP8U. In particular, the at least one axially recessed upshift initiation tooth SP8U includes a first axially recessed upshift initiation tooth SP8UA, a second axially recessed upshift initiation tooth SP8UB, a third axially recessed upshift initiation tooth SP8UC, and a fourth axially recessed upshift initiation tooth SP8UD. However, the total number of axially recessed upshift initiation teeth SP8U is not limited to this embodiment.

[0103] The axially recessed upshift initiation teeth SP2U to SP8U have essentially the same structure as the axially recessed upshift initiation tooth SP1U of the sprocket SP1. Therefore, for the sake of brevity, they are not described in detail here.

[0104] The teeth of other sprockets may incorporate the structures of the first downshift initiation tooth SP1N, the first axially recessed tooth SP1R, the axially recessed tooth SP1P, and the last chain-shifting tooth SP1T of sprocket SP1. As shown in Fig. As can be seen in Figure 5, the multiple sprocket teeth SP2B, for example, include a first downshift initiation tooth SP2N, a first axially recessed tooth SP2R, multiple axially recessed teeth SP2P, and multiple last chain-shifting teeth SP2T. As shown in Figure 5, the multiple sprocket teeth SP2B include, for example, a first downshift initiation tooth SP2N, a first axially recessed tooth SP2R, multiple axially recessed teeth SP2P, and multiple last chain-shifting teeth SP2T. Fig. As can be seen in Figure 7, the multiple sprocket teeth SP4B include a multiple of first downshift initiation teeth SP4N, a multiple of first axially recessed teeth SP4R, a multiple of axially recessed teeth SP4P, and a multiple of last chain-shifting teeth SP4T. As shown in Figure 7, the multiple of sprocket teeth SP4B includes a multiple of first downshift initiation teeth SP4N, a multiple of first axially recessed teeth SP4R, a multiple of axially recessed teeth SP4P, and a multiple of last chain-shifting teeth SP4T. Fig. As shown in Figure 8, the multiple sprocket teeth SP5B include a multiple of first downshift initiation teeth SP5N, a multiple of first axially recessed teeth SP5R, a multiple of axially recessed teeth SP5P, and a multiple of last chain-shifting teeth SP5T. As shown in Figure 8, the multiple of sprocket teeth SP5B includes a multiple of first downshift initiation teeth SP5N, a multiple of first axially recessed teeth SP5R, a multiple of axially recessed teeth SP5P, and a multiple of last chain-shifting teeth SP5T. Fig. As can be seen in Figure 9, the multiple sprocket teeth SP6B include a multiple of first downshift initiation teeth SP6N, a multiple of first axially recessed teeth SP6R, a multiple of axially recessed teeth SP6P, and a multiple of last chain-shifting teeth SP6T. As shown in Figure 9, the multiple of sprocket teeth SP6B includes a multiple of first downshift initiation teeth SP6N, a multiple of first axially recessed teeth SP6R, a multiple of axially recessed teeth SP6P, and a multiple of last chain-shifting teeth SP6T. Fig. As can be seen in Figure 10, the multiple sprocket teeth SP7B include a multiple of first downshift initiation teeth SP7N, a multiple of first axially recessed teeth SP7R, a multiple of axially recessed teeth SP7P, and a multiple of last chain-shifting teeth SP7T. As shown in Figure 10, the multiple of sprocket teeth SP7B includes a multiple of first downshift initiation teeth SP7N, a multiple of first axially recessed teeth SP7R, a multiple of axially recessed teeth SP7P, and a multiple of last chain-shifting teeth SP7T. Fig. As can be seen in Figure 11, the multitude of sprocket teeth SP8B includes a multitude of first downshift initiation teeth SP8N, a multitude of first axially recessed teeth SP8R, a multitude of axially recessed teeth SP8P and a multitude of last chain-shifting teeth SP8T.

[0105] The first downshift initiation teeth, SP2N to SP8N, have essentially the same structures as the first downshift initiation teeth, SP1N, of sprocket SP1. The first axially recessed teeth, SP2R to SP8R, have essentially the same structures as the first axially recessed tooth, SP1R, of sprocket SP1. The axially recessed teeth, SP2P to SP8P, have essentially the same structures as the axially recessed tooth, SP1P, of sprocket SP1. The last chain-shifting teeth, SP2T to SP8T, have essentially the same structures as the last chain-shifting tooth, SP1T, of sprocket SP1. Therefore, for the sake of brevity, they are not described in detail here.

[0106] As in Fig. As shown in Figure 12, the plurality of sprocket teeth SP9B includes an intermediate tooth SP9M and at least one axially recessed upshift tooth SP9X, which is axially recessed with respect to the axis of rotation A1. The at least one axially recessed upshift tooth SP9X is located in the at least one upshift facilitation area FU9. The axially recessed upshift tooth SP9X is configured to reduce interference between the bicycle chain C and the bicycle chain C during an upshift operation in which the bicycle chain C is shifted from the bicycle sprocket SP9 to the smaller bicycle chainring SP8. In this embodiment, the plurality of sprocket teeth SP9B includes a plurality of axially recessed upshift teeth SP9X. The axially recessed upshift tooth SP9X is located in the upshift facilitation area FU9. However, the total number of axially recessed upshift teeth SP9X is not limited to this embodiment.

[0107] The plurality of sprocket teeth SP9B includes at least one axially recessed downshift tooth SP9D, which is axially recessed with respect to the axis of rotation A1. The at least one axially recessed downshift tooth SP9D is located in the at least one downshift facilitation area FD9. The axially recessed downshift tooth SP9D is configured to reduce interference between the bicycle chain C and the bicycle chain C during a downshift operation in which the bicycle chain C is shifted from the smaller sprocket SP8 to the bicycle chainring SP9. In this embodiment, the plurality of sprocket teeth SP9B includes a plurality of axially recessed downshift teeth SP9D. The axially recessed downshift tooth SP9D is located in the downshift facilitation area FD9. However, the total number of axially recessed downshift teeth SP9D is not limited to this embodiment.The axially recessed downshift tooth SP9D has essentially the same structure as the first axially recessed tooth SP1R (. Fig. 4) of the SP1 sprocket.

[0108] As in Fig. As shown in Figure 12, the intermediate tooth SP9M can be an axially recessed downshift tooth configured to reduce interference between the chainring SP9 and the chain C during a downshift operation when the chain C is shifted from the smaller sprocket SP8 to the chainring SP9. The multiple sprocket teeth SP9B include multiple downshift initiation teeth SP9N configured to first engage the chain C during the downshift operation when the chain C is shifted from the smaller sprocket SP8 to the chainring SP9. The downshift initiation teeth SP9N are located in the downshift facilitation area FD9.

[0109] The SP9 chainring assembly includes a variety of first release teeth (SP9Y), a variety of second release teeth (SP9Q), and a variety of upshift facilitation teeth (SP9Z). The first release tooth (SP9Y) is configured to initially release the chain from the SP9 chainring during the upshifting process, when the chain is shifted from the SP9 chainring to the smaller SP8 chainring in the first chain phase. The second release tooth (SP9Q) is configured to initially release the chain from the SP9 chainring during the upshifting process, when the chain is shifted from the SP9 chainring to the smaller SP8 chainring in a second chain phase, which differs from the first. The second release tooth (SP9Q) is configured to facilitate the release of the chain from the SP9 chainring at the upshift tooth (SP9Z) during the upshifting process.The SP9Z upshift release tooth is configured to fully disengage from the bicycle chain C during the second chain phase of the upshifting process. The SP9Q second release tooth is configured to fully disengage from the bicycle chain C during the first chain phase of the upshifting process. The SP9Y first release tooth, the SP9Q second release tooth, and the SP9Z upshift release tooth are located in the FU9 upshifting release area.

[0110] The axially recessed SP9X high-speed tooth has essentially the same function as the axially recessed SP1P tooth ( Fig. 4) of the sprocket SP1. Thus, the axially recessed upshift tooth SP9X can be considered the axially recessed tooth SP9X. The first release tooth SP9Y and the second release tooth SP9Q have essentially the same function as the axially recessed upshift entry tooth SP1U ( Fig. 4) of the sprocket SP1. Thus, the first release tooth SP9Y and the second release tooth SP9Q can be considered as the axially recessed upshift initiation tooth SP9Y and the axially recessed upshift initiation tooth SP9Q. The second release tooth SP9Q and the upshift facilitation tooth SP9Z have essentially the same function as the last chain-shifting tooth SP1T ( Fig. 4) of the sprocket SP1. Thus, the second release tooth SP9Q and the high-shift facilitation tooth SP9Z can be considered as the last chain-shifting tooth SP9Q and the last chain-shifting tooth SP9Z.

[0111] As in Fig. As shown in Figure 3, the chainring body SP9A includes a first axially oriented surface SP9E and a second axially oriented surface SP9F. The first axially oriented surface SP9E and the second axially oriented surface SP9F point in the axial direction D2 with respect to the rotational center axis A1 of the bicycle chainring SP9. The second axially oriented surface SP9F is located on the rear side of the first axially oriented surface SP9E in the axial direction D2. The first axially oriented surface SP9E is configured such that, in an assembled state where the bicycle chainring SP9 is mounted on the bicycle 10, it faces the center plane 10A ( Fig. 1) of bicycle 10 shows.

[0112] As in Fig. As shown in Figure 37, at least one axially recessed upshift tooth SP9X is located without any further tooth in between on a downstream side in the direction of rotation D11 adjacent to the intermediate tooth SP9M. The axially recessed upshift tooth SP9X is positioned downstream of the intermediate tooth SP9M in the direction of rotation D11. At least one axially recessed downshift tooth SP9D is located on a downstream side in the direction of rotation D11 adjacent to the intermediate tooth SP9M without any further tooth in between. The axially recessed downshift tooth SP9D is positioned downstream of the intermediate tooth SP9M in the direction of rotation D11. However, another tooth may be provided between the axially recessed downshift tooth SP9D and the intermediate tooth SP9M in the circumferential direction D1.

[0113] The intermediate tooth SP9M comprises a tooth tip section SP9M1, a running surface linear section SP9M2, and a non-running surface linear section SP9M3. The running surface linear section SP9M2 has a running surface angle AG1, defined between the running surface linear section SP9M2 and a first radial line RL1 extending from the rotation center axis A1 to a radially outermost edge E1 of the running surface linear section SP9M2. The non-running surface linear section SP9M3 has a non-running surface angle AG2, defined between the non-running surface linear section SP9M3 and a second radial line RL2 extending from the rotation center axis A1 to a radially outermost edge E2 of the non-running surface linear section SP9M3. The non-running surface angle AG2 is greater than the running surface angle AG1. The driving surface angle AG1 ranges from 0 degrees to 20 degrees. The non-driving surface angle AG2 ranges from 20 degrees to 60 degrees.In this embodiment, the driving surface angle AG1 is 8 degrees and the non-driving surface angle AG2 is 40 degrees. However, the driving surface angle AG1 is not limited to this embodiment and the above range. The non-driving surface angle AG2 is not limited to this embodiment and the above range.

[0114] The SP9 bicycle chainring comprises a first non-stepped inclination SP9M4, which is provided in the circumferential direction D1 with respect to the axis of rotation A1 between the at least one axially recessed high-shift tooth SP9X and the intermediate tooth SP9M. The SP9 bicycle chainring further comprises a second non-stepped inclination SP9M5, which is provided in the circumferential direction D1 between the at least one axially recessed low-shift tooth SP9D and the first non-stepped inclination SP9M4. However, the second non-stepped inclination SP9M5 may be omitted in the SP9 bicycle chainring.

[0115] As in Fig. As shown in Figure 38, a first axial thickness AT1 is defined in the axial direction D2 from the first non-stepped inclination SP9M4 to the first axially aligned surface SP9E. A second axial thickness AT2 is defined in the axial direction D2 from the second non-stepped inclination SP9M5 to the first axially aligned surface SP9E. The first non-stepped inclination SP9M4 extends circumferentially in the direction D1 from the intermediate tooth SP9M to the axially recessed upshift tooth SP9X to gradually reduce the first axial thickness AT1. The second non-stepped inclination SP9M5 extends circumferentially in the direction D1 from the first non-stepped inclination SP9M4 towards the axially recessed downshift tooth SP9D to gradually reduce the second axial thickness AT2. Thus, both the first non-stepped inclination SP9M4 and the second non-stepped inclination SP9M5 are step-free.The maximum value of the first axial thickness AT1 is equal to the maximum value of the second axial thickness AT2. Thus, the first non-stepped slope SP9M4 is continuously and, in the circumferential direction D1, continuously connected to the second non-stepped slope SP9M5.

[0116] The drive tooth tip section SP9M1 is arranged at least partially closer to the first axially oriented surface SP9E than to the second axially oriented surface SP9F in the axial direction D2. In this embodiment, the drive tooth tip section SP9M1 is arranged partially closer to the first axially oriented surface SP9E than to the second axially oriented surface SP9F in the axial direction D2.

[0117] As in Fig. As can be seen in Figure 13, the SP10B sprocket tooth variety includes a variety of SP10M intermediate teeth, a variety of SP10X axially recessed upshift teeth, a variety of SP10D axially recessed downshift teeth, a variety of SP10N down-entry teeth, a variety of SP10Y first release teeth, a variety of SP10Q second release teeth, and a variety of SP10Z upshift facilitation teeth. Fig. As can be seen in Figure 14, the variety of sprocket teeth SP11B includes a variety of intermediate teeth SP11M, a variety of axially recessed upshift teeth SP11X, a variety of axially recessed upshift teeth SP11D, a variety of downshift initiation teeth SP11N, a variety of first release teeth SP11Y, a variety of second release teeth SP11Q, and a variety of upshift facilitation teeth SP11Z. As shown in Fig. As can be seen in Figure 15, the variety of sprocket teeth SP12B includes a variety of intermediate teeth SP12M, a variety of axially recessed upshift teeth SP12X, a variety of axially recessed downshift teeth SP12D, a variety of downshift initiation teeth SP12N, a variety of first release teeth SP12Y, a variety of second release teeth SP12Q and a variety of upshift facilitation teeth SP12Z.

[0118] The axially recessed upshift teeth SP10X, SP11X, and SP12X have essentially the same structure as the axially recessed upshift teeth SP9X of the SP9 sprocket. Therefore, the axially recessed upshift teeth SP10X, SP11X, and SP12X can be considered equivalent to the axially recessed teeth SP10X, SP11X, and SP12X. The axially recessed teeth SP10D, SP11D, and SP12D have essentially the same structure as the axially recessed teeth SP9D of the SP9 sprocket. The downshift initiation teeth SP10N, SP11N, and SP12N have essentially the same structure as the downshift initiation teeth SP9N of the SP9 sprocket. The first release teeth SP10Y, SP11Y, and SP12Y have essentially the same structure as the first release teeth SP9Y of the SP9 sprocket. Thus, the first release teeth SP10Y, SP11Y and SP12Y can be considered as the axially recessed upshift initiation teeth SP10Y, SP11Y and SP12Y.The second release teeth SP10Q, SP11Q, and SP12Q have essentially the same structure as the second release teeth SP9Q of the SP9 sprocket. Therefore, the second release teeth SP10Q, SP11Q, and SP12Q can be considered the axially recessed upshift initiation teeth SP10Q, SP11Q, and SP12Q, or the last chain-shifting teeth SP10Q, SP11Q, and SP12Q. The upshift facilitation teeth SP10Z, SP11Z, and SP12Z have essentially the same structure as the upshift facilitation teeth SP9Z of the SP9 sprocket. Therefore, the upshift facilitation teeth SP10Z, SP11Z, and SP12Z can be considered the last chain-shifting teeth SP10Z, SP11Z, and SP12Z. Accordingly, they are not described in detail here for the sake of brevity.

[0119] The structure of the axially recessed high-shift entry tooth SP1U of the sprocket SP1 can apply to sprockets SP9 to SP12. As, for example, in Fig. As shown in Figure 39, the structure of the axially recessed upshift initiation tooth SP1U can be applied to the sprocket teeth SP9B of the sprocket SP9. In this modification, the plurality of sprocket teeth SP9B can include at least one axially recessed upshift initiation tooth SP9U, which is recessed axially with respect to the axis of rotation A1. In particular, the at least one axially recessed upshift initiation tooth SP9U includes a first axially recessed upshift initiation tooth SP9UA, a second axially recessed upshift initiation tooth SP9UB, a third axially recessed upshift initiation tooth SP9UC, and a fourth axially recessed upshift initiation tooth SP9UD.

[0120] As in Fig. As shown in Figure 40, the structure of the axially recessed upshift initiation tooth SP1U can be applied to the sprocket teeth SP10B of the sprocket SP10. In this modification, the plurality of sprocket teeth SP10B can include at least one axially recessed downshift initiation tooth SP10U, which is recessed axially with respect to the rotational center axis A1. In particular, the at least one axially recessed upshift initiation tooth SP10U includes a first axially recessed upshift initiation tooth SP10UA, a second axially recessed upshift initiation tooth SP10UB, a third axially recessed upshift initiation tooth SP10UC, and a fourth axially recessed upshift initiation tooth SP10UD.

[0121] As in Fig. As shown in Figure 41, the structure of the axially recessed high-shift initiation tooth SP1U can be applied to the sprocket teeth SP11B of the sprocket SP11. In this modification, the plurality of sprocket teeth SP11B can include at least one axially recessed high-shift initiation tooth SP11U, which is axially recessed with respect to the rotational center axis A1. In particular, the at least one axially recessed high-shift initiation tooth SP11U includes a first axially recessed high-shift initiation tooth SP11UA, a second axially recessed high-shift initiation tooth SP11UB, a third axially recessed high-shift initiation tooth SP11UC, and a fourth axially recessed high-shift initiation tooth SP11UD.

[0122] As in Fig. As shown in Figure 42, the structure of the axially recessed high-shift initiation tooth SP1U can be applied to the sprocket teeth SP12B of the sprocket SP12. In this modification, the plurality of sprocket teeth SP12B can include at least one axially recessed high-shift initiation tooth SP12U, which is axially recessed with respect to the rotational center axis A1. In particular, the at least one axially recessed high-shift initiation tooth SP12UU includes a first axially recessed high-shift initiation tooth SP12UA, a second axially recessed high-shift initiation tooth SP12UB, a third axially recessed high-shift initiation tooth SP12UC, a fourth axially recessed high-shift initiation tooth SP12UD, and a fifth axially recessed high-shift initiation tooth SP12UE.

[0123] In the embodiment described above, the sprocket teeth have essentially the same axial width. However, the axial width of one sprocket tooth can differ from that of another. For example, the sprocket teeth can have an inner-link engagement tooth and an outer-link engagement tooth. The axial width of the outer-link engagement tooth is greater than the axial width of the inner-link engagement tooth. The axial width of the engagement of the outer-link engagement tooth is greater than the axial distance between the opposing pair of inner link plates and less than the axial distance between the opposing pair of outer link plates. The axial width of the inner-link engagement tooth is less than the axial distance between the opposing inner link plates.

[0124] In the above embodiment, as in Fig. As shown in Figure 1, crank arrangement 2 includes the front chainring 2D as a single chainring. However, crank arrangement 2 can include multiple chainrings. If crank arrangement 2 includes the front chainring 2D as a single chainring, it is possible to save weight in the bicycle drivetrain 11. If crank arrangement 2 includes multiple chainrings, it is possible to increase the total number of gears in the bicycle drivetrain 11.

[0125] In the above embodiment, as in Fig.The combination of total tooth counts for sprockets SP1 to SP12 shown in diagram 43 is 10, 12, 14, 16, 18, 21, 24, 28, 32, 36, 40, and 45. However, the bicycle's multi-chainring 12 can also have other combinations of total tooth counts for sprockets SP1 to SP12. For example, another combination of total tooth counts for sprockets SP1 to SP12 could be 10, 12, 14, 16, 18, 21, 24, 28, 33, 39, 45, and 51. In a case where the total number of sprockets is 11, another combination of the total tooth counts of sprockets SP1 to SP12 can be 10, 12, 14, 16, 18, 21, 24, 28, 33, 39 and 45.

[0126] Obviously, in light of the above teachings, numerous modifications and variations of the present invention are possible. It should therefore be understood that the invention can be exercised differently within the scope of the appended claims than expressly described herein. REFERENCE NUMBERS 2 Crank arrangement 2A Crank axle 2B right crank arm 2C left crank arm 2D front sprocket 4 Hub arrangement 4A Locking element 4B Sprocket support body 10 bicycles 10A Middle Level 11 Bicycle drivetrain 12 Bicycle multi-chainring 14 Sprocket carrier 16 Hub engagement part 18 Sprocket mounting arm 19 Hub internal gearing 20 first hub internal toothing 22 second hub internal toothing 24 ring-shaped recesses 28 first internal teeth 30 second internal teeth A1 pivot axis AD axial distance AG1 Driving surface angle AG2 Non-driving surface angle AT1 first axial thickness AT2 second axial thickness BF bicycle frame C bicycle chain C1 inner connecting tab C11 first internal connection end section C11A first longitudinally extended edge C11B first internal connection opening C12 second inner connection end section C12A second longitudinally extended edge C12B second internal connection opening C13 Internal connecting section C2 outer connecting tab C2A outer connecting space CA11 first central axis CA12 second central axis CL1 Longitudinal centerline CP1 axial center D1 Circumferential direction D11 rotary direction of travel D12 reverse direction of rotation D2 axial direction D3 Longitudinal direction D31 first longitudinal direction D32 second longitudinal direction DM1 to DM12 first to twelfth maximum outer diameter DS1 first distance DS2 second distance E1, E2 radial outermost edge E11 driving surface side tooth tip end E12 non-driving-surface tooth tip end F1 drive torque F6, F7, F9 to F12 Fastener FD1 to FD12 first downshift relief range FU1 to FU12 high-voltage switch relief area RC1 to RC12 Tooth base RD1 first radial distance RD2 second radial distance RH1 Tooth radial height RH2 radial height RL1 first radial line RL2 second radial line SC6, SC9, SC12 spacers SP variety of sprockets SP1 to SP12 first to twelfth sprocket SP1A to SP12 first to twelfth sprocket body SP1A1 first axially aligned surface SP1A2 second axially aligned surface SP1B to SP12B first to twelfth sprocket teeth SP1C to SP12 Tooth base SP1E, SP2E first, second inner bicycle surface SP1F, SP2F first, second bicycle-side surface SP1H, SP2H, SP4H, SP4H internal teeth SP1L to SP4L chain bending limiting tooth SP1N to SP8N first downshift initiation tooth SP1P to SP8P axially recessed tooth SP1R to SP8R first axially recessed tooth SP1R1 recess SP1S, SP2S, SP4S internal gearing SP1T to SP8T last chain-shifting tooth SP1U to SP12U axially recessed upshift initiation tooth SP1U1 Driving surface SP1U2 Non-driving area SP1U3 Tooth tip section SP1U4 Non-driving surface protrusion SP1U5 Leading position SP1U6 Guide Incline SP1UA to SP12UA first axially recessed upshift initiation tooth SP1UB to SP12UB second axially recessed upshift initiation tooth SP6UC to SP12UC third axially recessed upshift initiation tooth SP8UD to SP12UD fourth axially recessed upshift initiation tooth SP12UE fifth axially recessed upshift initiation tooth SP2A1, SP2A2 surface SP2A3 axially recessed section SP2G additional internal teeth SP2L1 Chain bending limiting surface SP2L2 beveled section SP2L3 Tooth tip SP2L4 additional chamfered section SP2L6 upstream area SP2L7 downstream area SP2L8 additional downstream area SP2M second sprocket teeth SP2M3 Tooth tip SP2O torque transmission profile SP3F torque transmission profile SP3G external teeth SP9D to SP12D axially recessed downshift number SP9E first axially aligned surface SP9F second axially aligned surface SP9M to SP12M Intermediate tooth SP9M1 Driving tooth tip section SP9M2 Driving surface linear section SP9M3 Non-road surface linear section SP9M4 first non-stepped inclination SP9M5 second non-stepped incline SP9N to SP12N downshift induction teeth SP9Q to SP12Q second release teeth SP9X to SP12X axially recessed upshift tooth SP9Y to SP12Y first release teeth SP9Z to SP12Z high-speed shifter teeth TR radial tooth area TR1 radial outermost end TR2 radial innermost end

Claims

[1] A bicycle chainring (SP1 to SP12), comprising: a sprocket body (SP1A to SP12A) with a first axially oriented surface (SP1A1) and a second axially oriented surface (SP1A2) which are aligned in the axial direction (D2) with respect to a rotational center axis (A1) of the bicycle sprocket (SP1 to SP12), wherein the second axially oriented surface (SP1A2) is provided in the axial direction (D2) on a rear side of the first axially oriented surface (SP1A1), wherein the first axially oriented surface (SP1A1) is configured to point in a mounted state in which the bicycle sprocket (SP1 to SP12) is mounted on a bicycle (10) in the direction of a median plane (10A) of the bicycle (10); a plurality of sprocket teeth (SP1B to SP12B) extending radially outwards from the sprocket body (SP1A to SP12A) with respect to the axis of rotation (A1); at least one upshift facilitation area (FU1 to FU12) configured to facilitate the transfer of a bicycle chain (C) from the bicycle sprocket (SP1 to SP12) to a smaller bicycle sprocket (SP1 to SP11) located axially (D2) adjacent to the bicycle sprocket (SP1 to SP12) without another bicycle sprocket in between; wherein the plurality of sprocket teeth (SP1B to SP12B) includes at least one axially recessed, upshifting initiation tooth (SP1U to SP12U) which is axially recessed with respect to the rotational center axis (A1); wherein the at least one axially recessed upshift initiation tooth (SP1U to SP12U) is arranged and configured in the at least one upshift facilitation area (FU1 to FU12) to release an inner connecting link (C1) of the bicycle chain (C) from the at least one axially recessed upshift initiation tooth (SP1U to SP12U) during an upshift operation in which the bicycle chain (C) changes from the main chainring (SP1 to SP12) to the smaller bicycle chainring (SP1 to SP11); wherein the at least one axially recessed upshift initiation tooth (SP1U to SP12U) has a driving surface (SP1U1), a non-driving surface (SP1U2) and a tooth tip section (SP1U3); wherein the driving surface (SP1U1) includes a driving surface-side tooth tip end (E11); wherein the non-driving surface (SP1U2) includes a non-driving surface tooth tip end (E12); the tooth tip section (SP1U3) connects the driving surface side tooth tip end (E11) and the non-driving surface side tooth tip end (E12); the non-driving surface (SP1U2) which extends from the non-driving surface tooth tip end (E12) in a circumferential direction (D1) with respect to the rotation center axis (A1); the non-riding surface (SP1U2) has a non-riding surface projection (SP1U4) which is arranged radially inside the non-riding surface tooth tip end (E12) with respect to the axis of rotation (A1); and wherein the non-riding surface projection (SP1U4) has a projection tip (SP1U5) which is located in the axial direction (D2) closer to the second axially oriented surface (SP1A2) than the non-riding surface tooth tip end (E12), so that a guide chamfer (SP1U6) extends from the projection tip (SP1U5) to the first axially oriented surface (SP1A1). [2] The bicycle chainring (SP1 to SP12) according to claim 1, wherein the projection tip (SP1U5) is arranged radially inside the non-riding surface tooth tip end (E12) with respect to the rotation center axis (A1). [3] The bicycle chainring (SP1 to SP12) according to claim 1 or 2, wherein the projection tip (SP1U5) is arranged radially outside a tooth base (RC1) of the bicycle chainring (SP1 to SP12) with respect to the axis of rotation (A1). [4] The bicycle chainring (SP1 to SP12) according to any one of claims 1 to 3, wherein the multitude of sprocket teeth (SP1B to SP12B) adjacent to the at least one axially recessed upshift initiation tooth (SP1U to SP12U) includes a last chain-shifting tooth (SP1T), the last chain-switching tooth (SP1T) is arranged with respect to a direction of rotation (D11) on a downstream side of the at least one axially recessed up-switching initiation tooth (SP1U to SP12U), and The last chain-shifting tooth (SP1T) is configured to be the last to detach from an outer connecting link (C2) of the bicycle chain (C) during the upshifting process. [5] The bicycle chainring (SP1 to SP12) according to any one of claims 1 to 4, wherein the plurality of chainring teeth (SP1B to SP12B) adjacent to the at least one axially recessed upshifting initiation tooth (SP1U to SP12U) includes at least one axially recessed tooth (SP1P) without any other tooth in a circumferential direction (D1) with respect to the axis of rotation (A1) on an upstream side of the at least one axially recessed upshifting initiation tooth (SP1U to SP12U) with respect to a direction of rotation (D11). [6] The bicycle chainring (SP1 to SP12) according to any one of claims 1 to 5, wherein the at least one axially recessed upshifting initiation tooth (SP1U to SP12U) comprises a plurality of axially recessed upshifting initiation teeth (SP1U to SP12U). [7] The bicycle chainring (SP1 to SP12) according to any one of claims 1 to 5, wherein the at least one axially recessed upshift initiation tooth (SP1U to SP12U) includes a first axially recessed upshift initiation tooth (SP1UA to SP12UA) and a second axially recessed upshift initiation tooth (SP1UB to SP12UB), and the total number of teeth of the bicycle chainring (SP1 to SP12) is equal to or greater than 11. [8] The bicycle chainring (SP6 to SP12) according to any one of claims 1 to 5, wherein the at least one axially recessed upshift initiation tooth (SP6U to SP12U) comprises a first axially recessed upshift initiation tooth (SP6UA to SP12UA), a second axially recessed upshift initiation tooth (SP6UB to SP12UB) and a third axially recessed upshift initiation tooth (SP6UC to SP12UC), and the total number of teeth of the bicycle chainring (SP6 to SP12) is equal to or greater than 19. [9] The bicycle chainring (SP8 to SP12) according to any one of claims 1 to 5, wherein the at least one axially recessed upshift initiation tooth (SP8U to SP12U) comprises a first axially recessed upshift initiation tooth (SP8UA to SP12UA), a second axially recessed upshift initiation tooth (SP8UB to SP12UB), a third axially recessed upshift initiation tooth (SP8UC to SP12UC) and a fourth axially recessed upshift initiation tooth (SP8UD to SP12UD), and the total number of teeth of the bicycle chainring (SP8 to SP12) is equal to or greater than 25. [10] The bicycle chainring (SP12) according to any one of claims 1 to 5, wherein the at least one axially recessed upshift initiation tooth (SP12U) comprises a first axially recessed upshift initiation tooth (SP12UA), a second axially recessed upshift initiation tooth (SP12UB), a third axially recessed upshift initiation tooth (SP12UC), a fourth axially recessed upshift initiation tooth (SP12UD) and a fifth axially recessed upshift initiation tooth (SP12UE), and the total number of teeth of the bicycle chainring (SP12) is equal to or greater than 41. [11] A bicycle drive train (11), comprising: the bicycle chainring (SP1 to SP12) according to one of claims 1 to 5; and a bicycle chain (C) comprising an inner connecting link (C1) which includes the following: a first internal connection end section (C11); a second internal connection end section (C12); and an internal connecting intermediate section (C13) that connects the first internal connecting end section (C11) and the second internal connecting end section (C12). [12] The bicycle drive train (11) according to claim 11, wherein the first inner connection end section (C11) has a first longitudinally extended edge (C11A) in a longitudinal direction (D3) with respect to a longitudinal center line (CL1) of the inner connection tab (C1), the first longitudinally extended edge (C11A) extends in a first longitudinal direction (D31) defined along the longitudinal direction (D3) from the second internal connection end section (C12) to the first internal connection end section (C11), and the first longitudinally extended edge (C11A) is configured to support, in an engagement state in which one of the plurality of sprocket teeth (SP1B to SP12B) is positioned in an outer connection space (C2A) defined between a pair of outer connecting links (C2) of the bicycle chain (C), one of the plurality of sprocket teeth (SP1B to SP12B) of the bicycle sprocket (SP1 to SP12) in the axial direction (D2). [13] The bicycle drive train (11) according to claim 12, wherein the second inner connection end section (C12) has a second longitudinally extended edge (C12A) in the longitudinal direction (D3), the second longitudinally extended edge (C12A) extends in a second longitudinal direction (D32) which is defined along the longitudinal direction (D3) from the first internal connection end section (C11) to the second internal connection end section (C12), and the second longitudinally extended edge (C12A) is configured to support one of the multitude of chainring teeth (SP1B to SP12B) of the bicycle chainring (SP1 to SP12) in an axial direction (D2) in an engagement state in which one of the plurality of chainring teeth (SP1B to SP12B) is positioned in an outer connection space (C2A) defined between a pair of outer connecting links (C2) of the bicycle chain (C).

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