CN222291923U - Bicycle fluted disc structure - Google Patents

Abstract

The utility model discloses a bicycle gear disc structure, comprising: a gear disc body, which can be driven to rotate along a rotating axis; the gear disc body has a first side surface and a second side surface respectively on two opposite sides along the axial direction of the rotating axis, and the first side surface is adjacent to an adjacent smaller gear disc body than the second side surface; a plurality of meshing teeth are arranged on the outer peripheral surface of the gear disc body for a chain to mesh; a shift-up promoting part is arranged on the gear disc body, and is used to promote the chain to shift up from the gear disc body to the adjacent smaller gear disc body; the shift-up promoting part has a first shift-up promoting tooth and a second shift-up promoting tooth; the first shift-up promoting tooth has a first shift-up recess, which is formed on the first side surface of the gear disc body and is recessed in a direction toward the second side surface; the second shift-up promoting tooth is adjacent to the first shift-up promoting tooth in a circumferential direction and there is no other tooth therebetween, and the second shift-up promoting tooth has a second shift-up recess, which is formed on the first side surface of the gear disc body and is recessed in a direction toward the second side surface.

Description

Bicycle fluted disc structure

Technical Field

The present utility model relates to bicycles, and more particularly, to a bicycle chainring structure.

Background

The existing bicycle can change speed through fluted discs with different sizes when riding, basically, the front and rear speed changers are used for combining the fluted discs with different sizes, and the transmission ratio of the chain among the fluted discs is changed. Such a design enables the rider to adjust the rotational speed of the pedals under different conditions to cope with different speeds and terrain.

Generally, one of the most common shifting methods is to shift through a rear derailleur and a flywheel. The rear wheel of a bicycle is typically provided with a plurality of rear chainrings, each chainring having a different number of teeth, and a rear derailleur positioned on the frame of the rear wheel. The function of the rear derailleur is to change the size of the rear chaining plate to which the chain is connected. With the front cog unchanged, the larger rear cog provides a lower gear ratio, making it easier for the rider to ascend. The smaller rear chainring provides a higher gear ratio suitable for use on a quick level road.

However, when the chain is shifted from a larger gear to a smaller gear, problems often occur, such as the fact that the chain needs a period of time to shift from one gear to another during shifting due to the gear structure, which can result in a significant feeling of separation of the bicycle from one gear to another during shifting, affecting the riding comfort of the rider, which is particularly pronounced when shifting continuously through multiple gear segments.

Disclosure of utility model

The utility model aims to provide a bicycle fluted disc structure which can effectively promote the stability of upshifting operation and reduce the paragraph feeling generated during upshifting.

In order to achieve the above object, the present utility model provides a bicycle chainring structure comprising a chainring body driven to rotate along a rotation axis, the chainring body having a first side and a second side along axially opposite sides of the rotation axis, the first side being adjacent to an adjacent smaller chainring body than the second side, a plurality of engaging teeth provided on an outer circumferential surface of the chainring body for engaging a chain, an upshift promoting portion provided on the chainring body for promoting upshifting of the chain from the chainring body to the adjacent smaller chainring body, the upshift promoting portion having a first upshift promoting tooth and a second upshift promoting tooth, the first upshift promoting tooth having a first upshift promoting tooth recess formed in the first side of the chainring body and recessed in a direction toward the second side, the second upshift promoting tooth being adjacent to the first upshift promoting tooth in a circumferential direction and having no other tooth therebetween, the second upshift promoting tooth having a second upshift promoting tooth recess formed in the first side of the chainring body and recessed in a direction toward the second side opposite to the first upshift promoting tooth inhibiting portion, the first upshift promoting tooth being formed in a direction toward the adjacent to the second side of the upshift promoting tooth inhibiting portion, the first upshift promoting tooth and the second upshift promoting tooth are offset in a direction toward the second side surface, and the upshift inhibiting tooth is offset in a direction toward the first side surface with respect to the first upshift promoting tooth and the second upshift promoting tooth.

In one embodiment, the fluted disc body defines a central line along an axial width direction perpendicular to the rotating shaft, the top of the first upshift promoting tooth is provided with a first tooth top surface, and an included angle which is different from 0 is formed between the first tooth top surface and the central line clamp, so that the distance between one end of the first upshift promoting tooth away from the second upshift promoting tooth and the first side surface is larger than the distance between one end of the first upshift promoting tooth close to the second upshift promoting tooth and the first side surface.

In one embodiment, the top of the second upshift promoting tooth has a second top surface, and the second top surface forms an angle with the center wire clamp that is not equal to 0, such that the distance between the end of the second upshift promoting tooth that is close to the first upshift promoting tooth and the first side surface is greater than the distance between the end of the second upshift promoting tooth that is far from the first upshift promoting tooth and the first side surface.

In one embodiment, the first upshift recess has a first concave side surface and a first concave bottom surface, the first concave side surface is connected to the first concave bottom surface, the second upshift recess has a second concave side surface and a second concave bottom surface, the second concave side surface is connected to the second concave bottom surface, and the first concave side surface is separated from the second concave side surface.

In one embodiment, the first concave side of the first upshift recess forms an angle with the first side of the first upshift recess, and the second concave side of the second upshift recess is approximately parallel to the first side of the first upshift recess such that the first concave side is inclined with respect to the second concave side.

In one embodiment, the width of the first concave bottom surface tapers from an end away from the second upshift facilitating tooth toward an end approaching the second upshift facilitating tooth such that the width of the root of the first upshift facilitating tooth in an axial width direction parallel to the rotation axis increases from an end away from the second upshift facilitating tooth toward an end approaching the second upshift facilitating tooth.

In one embodiment, the upshift inhibiting portion further includes an upshift limiting tooth adjacent to a side of the first upshift promoting tooth opposite to the second upshift promoting tooth in a circumferential direction without another tooth between the upshift limiting tooth and the first upshift promoting tooth, the upshift limiting tooth having a limiting recess formed in the second side face of the toothed disc body and recessed in a direction toward the first side face so that the upshift limiting tooth is offset in a direction toward the first side face.

In one embodiment, the root width of the upshift limiting tooth in an axial width direction parallel to the rotation shaft is smaller than the root width of the engagement tooth in the axial width direction parallel to the rotation shaft.

In an embodiment, the second upshift promoting tooth further includes a third upshift recess formed on the first side surface of the fluted disc body and recessed in a direction toward the second side surface, wherein the third upshift recess is located at a side of the second upshift recess opposite to the first upshift recess and is communicated with the second upshift recess.

In an embodiment, the third upshift recess is a C-shaped recess with an upward notch and has a third concave side and a third concave bottom, wherein the third concave side is approximately parallel to the first side, the third concave bottom is connected to the third concave side and is inclined relative to the first side, and the third concave side of the third upshift recess is separated from the second concave side of the second upshift recess.

The bicycle fluted disc structure has the beneficial effects that the stability of upshift operation can be effectively promoted, and the paragraph sense generated during upshift is reduced.

Drawings

The following description will illustrate preferred embodiments according to the objects and effects of the present utility model, and is provided with reference to the drawings.

FIG. 1 is a front elevational view of a bicycle chainring set in accordance with a preferred embodiment of the present utility model.

FIG. 2 is a right side view of a bicycle chainring set in accordance with a preferred embodiment of the present utility model.

FIG. 3 is a front view of a larger chainring body in accordance with a preferred embodiment of the present utility model.

Fig. 4 is an enlarged partial front view of fig. 3.

Fig. 5 is a partially enlarged perspective view of fig. 3.

Fig. 6 is an enlarged partial top view of fig. 3.

FIG. 7 is a rear view of a larger chainring body in accordance with a preferred embodiment of the present utility model.

Fig. 8 is an enlarged partial rear view of fig. 7.

Fig. 9 is a partially enlarged perspective view of fig. 7.

FIG. 10 is a front view of a smaller chainring body in accordance with a preferred embodiment of the present utility model.

Fig. 11 is an enlarged partial front view of fig. 10.

FIG. 12 is an enlarged partial perspective view of FIG. 10

10. Base seat

12. Meshing teeth

14. First side surface

16. Second side surface

20. Upshift promoting portion

30. First upshift promoting teeth

32. First tooth top

34. First upshift recess

340. First side concave surface

342. First concave bottom

36. A first chamfer surface

40. Second upshift promoting teeth

42. Second tooth top

44. Second upshift recess

440. Second side concave surface

442. Second concave surface

46. Third upshift recess

460. Third side concave surface

462. Third concave bottom

48. Second chamfer surface

50. Upshift suppressing portion

52. Upshift inhibiting tooth

54. Upshift limiting tooth

540. Limiting concave part

542. Limiting side concave surface

544. Limiting the concave surface of the bottom

60. Upshift promoting portion

70. First upshift promoting teeth

72. First upshift recess

720. First side concave surface

722. First concave bottom

80. Second upshift promoting teeth

82. Second upshift recess

820. Second side concave surface

822. Second concave surface

84. Third upshift recess

840. Third side concave surface

842. Third concave bottom

90. Upshift inhibiting tooth

A rotating shaft

B center line

S bicycle fluted disc group

S1 fluted disc body

S2 fluted disc body

S3 fluted disc body

S4 fluted disc body

S5 fluted disc body

S6 fluted disc body

S7 fluted disc body

S8 fluted disc body

S9 fluted disc body

S10 fluted disc body

S11 fluted disc body

Detailed Description

The following description of the preferred embodiments of the utility model refers to the accompanying drawings. It is to be understood that the drawings and descriptions herein are proffered for purposes of illustration only and are not intended to limit the scope of the utility model. Further, the terms "upper" and "lower," left "and" right, "front" and "rear," first "and" second, "etc. as used in the specification are used herein to clearly describe the relative position between components or mechanisms and are not meant to be limiting.

Referring to fig. 1 and 2, a bicycle chainring set S according to a preferred embodiment of the present utility model is a rear chainring arrangement including a plurality of chainring bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11. The tooth disc bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11 are different in size and are arranged side by side from large to small along an axial direction of a rotation axis a, and at least a predetermined distance is provided between each adjacent tooth disc body S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11. The toothed disc bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11 are used for engagement by a chain (not shown), and an upshift operation can be accomplished by controlling a rear derailleur (not shown) to drive the chain to shift from a larger toothed disc body to an adjacent smaller toothed disc body in an upshift direction L1, or a downshift operation can be accomplished by controlling the rear derailleur to drive the chain to shift from a smaller toothed disc body to an adjacent larger toothed disc body in a downshift direction L2. The structure of the rear derailleur and the chain and the operation thereof are conventional, and are not essential to the present utility model, and detailed descriptions thereof are omitted herein.

In this embodiment, since the larger equal tooth plate bodies have substantially similar structures, one of the tooth plate bodies S11 will be described herein as an example, and the structures of the remaining tooth plate bodies can be self-supporting. Referring to fig. 3 to 6, the toothed disc body S11 has an annular base 10 and a plurality of engaging teeth 12, the engaging teeth 12 extend outwards along the radial direction of the base 10, and are annularly arranged in the circumferential direction of the toothed disc body S11 for engaging the chain. The fluted disc body S11 has a first side 14 and a second side 16 along opposite sides of the axial direction. The first side 14 faces the adjacent smaller toothed disc body S10 and the second side 16 faces away from the adjacent smaller toothed disc body S10. The toothed disc body S11 has at least one upshift promoting portion 20 near the circumferential edge, for example, the toothed disc body S11 has three upshift promoting portions 20 in this embodiment. Each of the upshift promoting portions 20 is configured to promote the upshift of the chain from the larger gear plate body S11 to the adjacent smaller gear plate body S10.

Specifically, the upshift promoting portions 20 include a first upshift promoting tooth 30 and a second upshift promoting tooth 40. The first upshift promoting tooth 30 and the second upshift promoting tooth 40 are adjacent to each other with no other tooth therebetween. As shown in fig. 6, the fluted disc body S11 has an imaginary center line B along the axial width center of the rotation axis a, and the center line B is located at the midpoint between the first side 14 and the second side 16. The top of the first upshift promoting tooth 30 has a first tooth top surface 32, and the extending direction of the first tooth top surface 32 forms an included angle with the center line B, which is different from 0, so that the distance between the first side 14 and the end of the first upshift promoting tooth 30 away from the second upshift promoting tooth 40 is greater than the distance between the first side 14 and the end of the first upshift promoting tooth 30 close to the second upshift promoting tooth 40. Whereby the first upshift promoting teeth 30 are arranged diagonally with respect to the engaging teeth 12. Wherein the first top land 32 of the first upshift promoting tooth 30 is offset toward the second side face 16 with respect to the center line B. The top of the second upshift promoting tooth 40 has a second tooth top surface 42, and the second tooth top surface 42 extends in a direction that forms an angle with the center line B that is different from 0, so that a distance between an end of the second upshift promoting tooth 40 that is close to the first upshift promoting tooth 30 and the first side 14 is greater than a distance between an end of the second upshift promoting tooth 40 that is away from the first upshift promoting tooth 30 and the first side 14. Whereby the second upshift promoting teeth 40 are arranged diagonally with respect to the engaging teeth 12. Wherein the second top land 42 of the second upshift promoting tooth 40 is offset toward the second side face 16 with respect to the center line B. Thereby, the chain more easily completes the upshifting action from the first upshifting promoting tooth 30 or the second upshifting promoting tooth 40.

Referring back to fig. 3-5, the first upshift promoting tooth 30 has a first upshift recess 34, and the first upshift recess 34 is formed in the first side 14 of the toothed disc body S11 and is recessed in a direction toward the second side 16. For reducing interference between the toothed disc body S11 and the chain during upshifting of the chain from the toothed disc body S11 to the adjacent smaller toothed disc body S10. Specifically, the first upshift recess 34 has a first concave side surface 340 and a first concave bottom surface 342. The first concave side surface 340 is connected to the first concave bottom surface 342, and the first concave bottom surface 342 is distant from the first top surface 32 of the first upshift promoting tooth 30 compared to the first concave side surface 340. The first concave side 340 forms an angle with the first side 14 that is not equal to 0, and the first concave bottom 342 is inclined with respect to the first side 14. The width of the first concave bottom surface 342 in the axial width direction parallel to the rotation axis a tapers from an end away from the second upshift promoting tooth 40 toward an end approaching the second upshift promoting tooth 40, such that the root width of the first upshift promoting tooth 30 in the axial width direction parallel to the rotation axis a increases from an end away from the second upshift promoting tooth 40 toward an end approaching the second upshift promoting tooth 40. Thereby, the first concave side 340 is also inclined from the end away from the second upshift promoting tooth 40 toward the end approaching the second upshift promoting tooth 40. In addition, the first upshift promoting tooth 30 further has a first chamfer surface 36. The first chamfer 36 is connected to the first concave side 340 and the first tooth top 32, respectively, and is inclined with respect to the first tooth top 32.

The second upshift promoting tooth 40 has a second upshift recess 44 and a third upshift recess 46, and the second upshift recess 44 and the third upshift recess 46 are in communication with each other, are formed in the first side surface 14 of the toothed disc body S11, and are recessed in a direction toward the second side surface 16. The second upshift recess 44 and the third upshift recess 46 serve to reduce interference between the toothed disc body S11 and the chain during upshifting of the chain from the toothed disc body S11 to the adjacent smaller toothed disc body S10. Specifically, the second upshift recess 44 has a second concave side surface 440 and a second concave bottom surface 442. The second concave side surface 440 is connected to the second concave bottom surface 442, and the second concave bottom surface 442 is further away from the second tooth top 42 than the second concave side surface 440. The second concave side surface 440 is generally parallel to the first side surface 14, and the second concave bottom surface 442 is inclined with respect to the first side surface 14. The third upshift recess 46 has a third side concave surface 460 and a third bottom concave surface 462. The third concave side 460 is connected to the third concave bottom 462 and the second concave side 440, and the third concave bottom 462 is further away from the second top surface 42 of the second upshift promoting tooth 40 than the third concave side 460 and is connected to the second concave bottom 442. The third concave side 460 is generally parallel to the first side 14, and the third concave bottom 462 is inclined with respect to the first side 14. Whereby the chain is guided by the second concave side surface 440 and the second concave bottom surface 442 of the second upshift recess 44 or the third concave side surface 460 and the third concave bottom surface 462 of the third upshift recess 46 onto the adjacent smaller toothed plate body S10. In addition, the second upshift promoting tooth 40 has a second chamfer 48. The second chamfer 48 is connected to the second concave side surface 440 and the second tooth top surface 42, respectively, and is inclined with respect to the second tooth top surface 42.

Wherein the first upshift recess 34 is separated from the second upshift recess 44, specifically, the first concave side 340 of the first upshift recess 34 is separated from the second concave side 440 of the second upshift recess 44, and the first concave bottom 342 of the first upshift recess 34 is separated from the second concave bottom 442 of the second upshift recess 44. Wherein the first concave side 340 of the first upshift recess 34 is inclined with respect to the first side 14, and the second concave side 440 of the second upshift recess 44 is planar with respect to the first side 14. The first concave side surface 340 of the first upshift recess 34 can also be referred to as being inclined with respect to the second concave side surface 440 of the second upshift recess 44.

According to the above structure, the bicycle chainring structure of the present utility model has two upshift modes, wherein the first upshift mode is to control the rear derailleur to shift the chain when the chain moves to the position of the first upshift promoting teeth 30 of the chainring body S11, so that the chain can enter the second upshift recess 44 along the first upshift recess 34 of the first upshift promoting teeth 30, and then move to the adjacent smaller chainring body S10 to complete the upshift. The second upshift mode is to control the rear derailleur to shift the chain as it moves to the position of the second upshift promoting teeth 40 of the toothed disc body S11, so that the chain enters the third upshift recess 46 along the second upshift recess 44 and moves to the next smaller toothed disc body S10 to complete the upshift. In either the first or second upshift mode, the upshift of the chain from the toothed disc body S11 to the adjacent smaller toothed disc body S10 is promoted by the structures of the first upshift promoting teeth 30 and the second upshift promoting teeth 40 of the upshift promoting portion 20, and the occurrence of a feeling of a paragraph due to the interference and time difference between the chain and the toothed disc body S11 during the upshift can be effectively reduced.

In addition to the upshift promoting portions 20, the present utility model also includes a corresponding upshift inhibiting portion 50 in the region of the fluted disc body S11 adjacent to each upshift promoting portion 20. For example, in the present embodiment, there are three such upshift inhibiting portions 50. The upshift inhibiting portion 50 includes an upshift inhibiting tooth 52. The upshift inhibiting tooth 52 and the second upshift promoting tooth 40 are adjacent to each other with no other tooth therebetween, whereby the second upshift promoting tooth 40 is located between the first upshift promoting tooth 30 and the upshift inhibiting tooth 52. Wherein the upshift inhibiting tooth 52 is offset relative to the first upshift promoting tooth 30 and the second upshift promoting tooth 40 in a direction toward the first side surface 14. The upshift inhibiting tooth 52 is used to inhibit the chain from performing an upshift operation. When the chain moves to the position of the upshift inhibiting tooth 52, since the upshift inhibiting tooth 52 is offset toward the first side surface 14, a main portion of the chain will fall on the back side of the upshift inhibiting tooth 52 and cannot be shifted by the rear derailleur, so that the upshift operation can be performed only when the chain is to be moved to the upshift promoting portion 20 of the next group. Therefore, the upshift inhibiting tooth 52 can restrict the chain from being shifted up only in the upshift promoting portion 20.

Referring to fig. 7 to 9, the upshift inhibiting portion 50 further includes two upshift limiting teeth 54, wherein the two upshift limiting teeth 54 are adjacent to each other without another tooth therebetween. And the two upshift limiting teeth 54 are located on the side of the first upshift facilitating tooth 30 opposite to the second upshift facilitating tooth 40. Wherein each of the two upshift limiting teeth 54 has a limiting recess 540. The two limiting recesses 540 are formed on the second side surface 16 and are recessed toward the first side surface 14. The confinement recess 540 has a confinement concave side 542 and a confinement concave bottom 544 connected. In this embodiment, limiting concave side 542 is approximately parallel to second side 16, and limiting concave bottom 544 is inclined with respect to second side 16. In another embodiment, the limiting concave surface and the second side surface form an included angle different from 0, so that the limiting concave surface is inclined relative to the second side surface. Due to the concave structure of the two restricting concave portions 540, the root width of the two upshift restricting teeth 54 in the axial width direction parallel to the rotation axis a is smaller than the root width of the remaining engaging teeth 12 in the axial width direction parallel to the rotation axis a, and the two upshift inhibiting teeth 54 are offset toward the first side face 14 with respect to the center line B (as shown in fig. 6). Thus, when the chain is located at the position of the two upshift limiting teeth 54, a portion of the chain will abut against the two limiting recesses 540, thereby preventing the chain from upshifting from the position of the two upshift limiting teeth 54. In other words, the two upshift limiting teeth 54 and the upshift inhibiting teeth 52 can respectively limit the chain from the circumferential direction in tandem so that the upshift operation is performed only when the chain is moved to the position of the upshift promoting portion 20.

It is to be noted that the upshift promoting portion of the present utility model may be configured in different configurations on the larger toothed disc and the smaller toothed disc. Fig. 10 to 12 show the structure of the toothed disc body S6 in this embodiment, and the structure of the remaining smaller toothed disc body can be self-deduced. The structure of the fluted disc body S6 is similar to that of the larger fluted disc body S11, and therefore, the detailed description thereof will be omitted. The fluted disc body S6 also has an upshift promoting portion 60, and the upshift promoting portion 60 includes a first upshift promoting tooth 70 and a second upshift promoting tooth 80. The first upshift facilitation tooth 70 has a first upshift recess 72, and the first upshift recess 72 has a first concave side surface 720 and a first concave bottom surface 722. The second upshift promoting tooth 80 has a second upshift recess 82 and a third upshift recess 84. The second upshift recess 82 has a second concave side surface 820 and a second concave bottom surface 822. The third upshift recess 84 has a third side concave surface 840 and a third bottom concave surface 842. Unlike the larger toothed disc body S11, the first bottom concavity 722 of the first upshift recess 72 of the toothed disc body S6 is connected to the second bottom concavity 822 of the second upshift recess 82, and the second bottom concavity 822 of the second upshift recess 82 is connected to the third bottom concavity 842 of the third upshift recess 84. The third upshift recess 84 is a C-shaped groove with an upward notch, and is formed between the second upshift promoting tooth 80 and an upshift inhibiting tooth 90 of the fluted disc body S6, and the third concave side surface 840 of the third upshift recess 84 is separated from the second concave side surface 820 of the second upshift recess 82.

In summary, the present utility model provides two upshift modes, in which the first upshift promoting teeth and the second upshift promoting teeth of the upshift promoting portion are configured to promote the upshift operation of the chain from the main body to the adjacent smaller main body, and to reduce the occurrence of a rattle caused by the interference between the chain and the main body during the upshift. On the other hand, the structure of the bicycle fluted disc of the utility model also limits the chain to carry out the upshift operation when the upshift promoting part through the structure of the post-upshift restraining tooth and the pre-upshift restraining tooth of the upshift restraining part, thereby effectively improving the smoothness degree during upshift.

The foregoing description of the preferred embodiments and designs of the present utility model is merely illustrative, not limiting, and not limiting, of the scope of the present utility model, which may be embodied in the equivalent manner or in the scope of the following claims, which are also intended to be covered by the applicant's claims without departing from the scope of the utility model.

Claims (10)

1. A bicycle fluted disc structure is characterized by comprising:

The fluted disc body can be driven to rotate along a rotating shaft, and the fluted disc body is provided with a first side surface and a second side surface along the axial opposite sides of the rotating shaft, wherein the first side surface is adjacent to an adjacent smaller fluted disc body compared with the second side surface;

A plurality of engaging teeth arranged on the outer peripheral surface of the fluted disc body for engaging a chain;

An upshift promoting portion provided on the toothed disc body for promoting upshift of the chain from the toothed disc body to the adjacent smaller toothed disc body, the upshift promoting portion having a first upshift promoting tooth and a second upshift promoting tooth, the first upshift promoting tooth having a first upshift recess formed on the first side surface of the toothed disc body and recessed in a direction toward the second side surface, the second upshift promoting tooth being adjacent to the first upshift promoting tooth in a circumferential direction without another tooth therebetween and having a second upshift recess formed on the first side surface of the toothed disc body and recessed in a direction toward the second side surface, and

The gear shift control device comprises a gear shift control part, a gear shift control part and a gear shift control part, wherein the gear shift control part is arranged on the gear shift main body and is adjacent to the gear shift control part and used for controlling the gear shift of the chain from the gear shift main body to the other gear shift main body which is smaller than the gear shift control part, the gear shift control part is provided with a gear shift control tooth which is adjacent to one side of the second gear shift control tooth relative to the first gear shift control tooth in the circumferential direction, no other tooth is arranged between the gear shift control tooth and the second gear shift control tooth, the first gear shift control tooth and the second gear shift control tooth are offset towards the direction of the second side, and the gear shift control tooth is offset towards the first side relative to the first gear shift control tooth and the second gear shift control tooth.

2. The bicycle chainring structure of claim 1, wherein the chainring body defines a centerline in a width direction perpendicular to the axis of rotation, the top of the first upshift promoting tooth has a first top surface, the first top surface forms an angle with the centerline of 0 or less such that a distance between an end of the first upshift promoting tooth away from the second upshift promoting tooth and the first side surface is greater than a distance between an end of the first upshift promoting tooth approaching the second upshift promoting tooth and the first side surface.

3. The bicycle chainring structure of claim 2, wherein the top of the second upshift promoting tooth has a second top surface, and wherein the second top surface forms an angle with the center wire clamp that is not equal to 0, such that a distance between an end of the second upshift promoting tooth proximate to the first upshift promoting tooth and the first side surface is greater than a distance between an end of the second upshift promoting tooth distal to the first upshift promoting tooth and the first side surface.

4. The bicycle chainring structure of claim 1, wherein the first upshift recess has a first concave side surface and a first concave bottom surface, the first concave side surface is connected to the first concave bottom surface, the second upshift recess has a second concave side surface and a second concave bottom surface, the second concave side surface is connected to the second concave bottom surface, and the first concave side surface is separated from the second concave side surface.

5. The bicycle chainring structure of claim 4, wherein the first concave side of the first upshift recess forms an angle with the first side of 0, and the second concave side of the second upshift recess is approximately parallel to the first side such that the first concave side is inclined with respect to the second concave side.

6. The bicycle chainring structure of claim 4, wherein the width of the first concave bottom surface tapers from an end away from the second upshift facilitating tooth toward an end approaching the second upshift facilitating tooth such that the width of the root of the first upshift facilitating tooth in an axial width direction parallel to the rotation axis increases from an end away from the second upshift facilitating tooth toward an end approaching the second upshift facilitating tooth.

7. The bicycle chainring structure of claim 1, wherein the upshift inhibiting portion further comprises an upshift limiting tooth circumferentially adjacent to a side of the first upshift promoting tooth opposite to the second upshift promoting tooth without another tooth therebetween, and wherein the upshift limiting tooth has a limiting recess formed in the second side surface of the chainring body and recessed in a direction toward the first side surface so that the upshift limiting tooth is offset in a direction toward the first side surface.

8. The bicycle chainring structure of claim 7, wherein the root width of the upshift limiting tooth in an axial width direction parallel to the rotation axis is smaller than the root width of the engaging tooth in the axial width direction parallel to the rotation axis.

9. The bicycle chainring structure of claim 4, wherein the second upshift promoting tooth further comprises a third upshift recess formed in the first side surface of the chainring body and recessed in a direction toward the second side surface, wherein the third upshift recess is located at a side of the second upshift recess opposite to the first upshift recess and is communicated with the second upshift recess.

10. The bicycle chainring structure of claim 9, wherein the third upshift recess portion is a C-shaped recess with an upward notch, and has a third concave side surface and a third concave bottom surface, the third concave side surface is approximately parallel to the first side surface, the third concave bottom surface is connected to the third concave side surface and is inclined relative to the first side surface, and the third concave side surface of the third upshift recess portion is separated from the second concave side surface of the second upshift recess portion.