JP2019001304A - Externally mounted gear box for bicycle - Google Patents

Abstract

To provide an externally mounted gear box for a bicycle which contributes to a cost reduction.SOLUTION: An externally mounted gear box for a bicycle comprises: a base member which is mounted on a frame of a bicycle; a movable member which is moved with respect to the base member; and a link mechanism which couples the base member and the movable member. The link mechanism includes: a first link arm; and a second link arm located closer to the frame than the first link arm when the base member is mounted on the frame. The first link arm comprises a first mounting member for mounting an urging member for applying urging force to the link mechanism on the link mechanism. The first mounting member is mounted on the first link arm so as to be detachable.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bicycle exterior transmission.

  A bicycle exterior transmission that changes the transmission ratio of a bicycle is known. The bicycle exterior transmission of Patent Document 1 as an example includes a base member attached to the bicycle, a movable member that moves relative to the base member, and a link mechanism that connects the base member and the movable member.

US Patent Application Publication No. 2005/0187050

Reduction of the cost of the bicycle exterior transmission is desired.
An object of the present invention is to provide a bicycle exterior transmission that can contribute to cost reduction.

A bicycle exterior transmission according to the first aspect of the present invention includes a base member attached to a bicycle frame, a movable member that moves relative to the base member, a link mechanism that connects the base member and the movable member, The link mechanism includes: a first link arm; and a second link arm that is closer to the frame than the first link arm when the base member is attached to the frame, The one link arm includes a first attachment member for attaching an urging member for applying an urging force to the link mechanism to the link mechanism, and the first attachment member is detachable from the first link arm. It is attached.
Since the link mechanism can be shared between the bicycle exterior transmission that requires the urging member to be attached to the link mechanism and the bicycle exterior transmission that does not require the urging member to be attached to the link mechanism, the cost of the bicycle exterior transmission can be reduced. Can be reduced.

In the bicycle exterior transmission of the second side according to the first side, the first attachment member includes a first shaft-like portion to which the urging member can be attached, and the first shaft-like portion is a first end portion. And a second end opposite to the first end.
For this reason, the urging member can be easily attached to the first attachment member.

In the bicycle exterior transmission of the third side according to the second side, the first shaft-shaped portion includes at least one engaging portion that can be engaged with the first link arm.
For this reason, the first attachment member can be stably attached to the first link arm.

In the bicycle exterior transmission according to the fourth aspect according to the third aspect, the at least one engagement portion includes a first screw portion.
For this reason, the first attachment member can be easily attached to and detached from the first link arm.

In the bicycle exterior transmission of the fifth side according to the fourth side, the first screw portion is provided in a portion of the first shaft-like portion that is closer to the first end than the second end.
For this reason, the first attachment member can be easily attached and detached as the first link arm.

In the bicycle exterior transmission of the sixth aspect according to the third aspect, the at least one engaging portion is provided in a portion of the first shaft-like portion that is closer to the first end portion than the second end portion. The first engagement portion, and a second engagement portion provided in a portion closer to the second end portion than the first end portion of the first shaft-shaped portion, and the first engagement portion Includes the first threaded portion, the first link arm is engaged with the first engaging portion, the third engaging portion, and the fourth engaging portion is engaged with the second engaging portion. including.
Since the first attachment member and the first link arm are engaged at a plurality of locations, the urging member can be stably held on the first attachment member.

In the bicycle exterior transmission according to the seventh aspect according to any one of the second to sixth aspects, the first end includes a tool engaging portion with which a tool can be engaged.
For this reason, the first attachment member can be easily attached to and detached from the first link arm.

In the bicycle exterior transmission according to the eighth aspect according to any one of the first to seventh aspects, the second link arm includes a second attachment member for attaching the urging member to the link mechanism, The second attachment member is detachably attached to the second link arm.
For this reason, the urging member can be easily attached to and detached from the first link arm and the second link arm.

In the bicycle exterior transmission according to the ninth aspect according to the eighth aspect, the second attachment member includes a fifth engagement portion, and the second link arm engages with the fifth engagement portion. Including joints.
For this reason, a 2nd attachment member can be stably attached to a 2nd link arm.

In the bicycle exterior transmission according to the tenth aspect according to the eighth or ninth aspect, the first link arm includes a first base member side portion close to the base member and a first movable member side portion close to the movable member. The second link arm includes a second base member side portion close to the base member and a second movable member side portion close to the movable member, and the first mounting member is the first link arm of the first link arm. A second member is detachably attached to the base member side portion, and the second attachment member is detachably attached to the second movable member side portion of the second link arm.
For this reason, the urging member can be easily attached to and detached from the first link arm and the second link arm.

In the bicycle exterior transmission according to the eleventh side according to any one of the eighth to tenth sides, one end of the urging member is attached to the first attachment member, and the second attachment member is attached to the first attachment member. The other end of the urging member is attached.
For this reason, the urging member can be easily attached to and detached from the first link arm and the second link arm.

In the bicycle exterior transmission according to the twelfth aspect according to the eleventh aspect, the link mechanism further includes the urging member.
For this reason, various urging members having different characteristics can be used for the link mechanism. Therefore, the customizability of the link mechanism is improved.

In the bicycle exterior transmission of the thirteenth side according to the twelfth side, the biasing member is a coil spring, and a hook for attaching to the first mounting member is provided at the one end.
For this reason, the urging member can be easily attached to the first attachment member.

The bicycle exterior transmission according to the fourteenth aspect according to any one of the first to thirteenth aspects further includes a motor unit for moving the movable member relative to the base member.
Since the link mechanism can be shared between an electric bicycle exterior transmission that requires an urging member attached to the link mechanism and an electric bicycle exterior transmission that does not require an urging member attached to the link mechanism, the bicycle exterior The cost of the transmission can be reduced.

In the bicycle exterior transmission according to the fifteenth aspect according to the fourteenth aspect, the motor unit includes a motor and a transmission mechanism that transmits a driving force of the motor to the link mechanism.
For this reason, the driving force of the motor is appropriately transmitted to the link mechanism.

A bicycle exterior transmission according to a sixteenth aspect of the present invention includes a base member attached to a bicycle frame, a movable member that moves relative to the base member, a chain guide that is rotatably attached to the movable member, and the base. A link mechanism for connecting the member and the movable member, and a motor unit for moving the movable member relative to the base member, the motor unit including a motor and a driving force of the motor A transmission mechanism for transmitting to a link mechanism, the link mechanism including a first link pin for connecting the base member and the link mechanism, and a second link pin for connecting the movable member and the link mechanism. The motor unit includes the first link pin or the first link pin. Constructed a link pin to rotate, the removable member includes a biasing member that biases the chain guide, the link mechanism does not include a biasing member.
For this reason, it is not necessary to use an urging member for the link mechanism. Therefore, the cost of the bicycle exterior transmission can be reduced.

In the bicycle exterior transmission of the seventeenth side according to the sixteenth side, the link mechanism includes a first link arm and a second link arm, and the first link arm is mounted when the base member is attached to the frame. The second link arm is farther from the frame.
For this reason, the cost of the bicycle exterior transmission can be reduced.

A bicycle exterior transmission according to an eighteenth aspect of the present invention includes a base member attached to a bicycle frame, a movable member that moves relative to the base member, and a link mechanism that connects the base member and the movable member; A motor unit for moving the movable member relative to the base member, the motor unit including a motor and a transmission mechanism for transmitting a driving force of the motor to the link mechanism, the link mechanism Includes a first link pin that connects the base member and the link mechanism, and a second link pin that connects the movable member and the link mechanism, and the motor unit includes the first link pin or the link mechanism The second link pin is configured to rotate, and biases the link mechanism. It does not include the energizing member.
For this reason, it is not necessary to use an urging member for the link mechanism. Therefore, the cost of the bicycle exterior transmission can be reduced.

In the bicycle exterior transmission according to the nineteenth aspect according to the eighteenth aspect, the link mechanism includes a first link arm and a second link arm, and the first link arm is mounted when the base member is attached to the frame. The second link arm is farther from the frame.
For this reason, the cost of the bicycle exterior transmission can be reduced.

In the bicycle exterior transmission according to the twentieth aspect according to any one of the first to 19th aspects, the bicycle exterior transmission is a rear derailleur.
Since the link mechanism can be shared between the rear derailleur that needs to attach the urging member to the link mechanism and the rear derailleur that does not need to attach the urging member to the link mechanism, the cost of the rear derailleur can be reduced.

  The bicycle exterior transmission of the present invention can contribute to cost reduction.

The partial side view of the bicycle carrying the bicycle exterior transmission of 1st Embodiment. The disassembled perspective view of the link mechanism of FIG. The fragmentary sectional view which shows the urging member of the link mechanism of FIG. 1, and its periphery. The partial side view of the bicycle carrying the bicycle exterior transmission of 2nd Embodiment.

(First embodiment)
With reference to FIG. 1, a configuration of a bicycle exterior transmission 20 (hereinafter, “exterior transmission 20”) mounted on the bicycle 10 will be described.

  The exterior transmission 20 is provided on the frame 12 of the bicycle 10. In the example shown in FIG. 1, the exterior transmission 20 is a rear derailleur 20 </ b> A provided at the rear end 12 </ b> A of the frame 12. A plurality of sprockets 14 are provided on a hub (not shown) supported by the rear end 12A so as to overlap each other. The exterior transmission 20 is electrically connected to, for example, a shift operation device provided on the handle of the bicycle 10 (not shown). By operating the speed change operation device, the exterior transmission 20 is driven, the chain 16 is switched from one sprocket 14 to another sprocket 14, and the speed ratio of the bicycle 10 is changed.

  The exterior transmission 20 includes a base member 22, a movable member 24, and a link mechanism 40. The base member 22 is attached to the frame 12 of the bicycle 10. In one example, the base member 22 is fixed to the rear end 12 </ b> A of the bicycle 10. The movable member 24 moves relative to the base member 22. The link mechanism 40 connects the base member 22 and the movable member 24. In one example, the link mechanism 40 is connected to the base member 22 to be rotatable with respect to the base member 22, and is connected to the movable member 24 to be rotatable with respect to the movable member 24.

  The exterior transmission 20 further includes a chain guide 30. The chain guide 30 is rotatably attached to the movable member 24. The chain guide 30 includes a guide member 32 and a pair of support plates 34. The guide member 32 is supported by the support plate 34 so as to be rotatable with respect to the support plate 34. The guide member 32 includes a first pulley 32A and a second pulley 32B. The first pulley 32 </ b> A is provided at the first end 34 </ b> A of the support plate 34 so as to be sandwiched between the pair of support plates 34. The second pulley 32B is provided at the second end 34B opposite to the first end 34A of the support plate 34 so as to be sandwiched between the pair of support plates 34. The chain 16 is wound around the first pulley 32A and the second pulley 32B.

  The movable member 24 includes a housing 26 and a biasing member 28. The biasing member 28 is provided in the housing 26. The urging member 28 urges the chain guide 30. In one example, the biasing member 28 biases one rotation of the chain guide 30 around the direction along the center axis of the first pulley 32A. An example of the urging member 28 is a torsion spring.

  The link mechanism 40 includes a first link arm 42, a second link arm 62, and a biasing member 80. The first link arm 42 is located farther from the frame 12 than the second link arm 62 when the base member 22 is attached to the frame 12. The second link arm 62 is located closer to the frame 12 than the first link arm 42 when the base member 22 is attached to the frame 12. The biasing member 80 applies a biasing force to the link mechanism 40.

  The first link arm 42 includes a first attachment member 50. The first attachment member 50 is a member for attaching the urging member 80 to the link mechanism 40. One end 84 of the urging member 80 is attached to the first attachment member 50 (see FIG. 3). In one example, the biasing member 80 is attached to the first link arm 42 by attaching one end 84 of the biasing member 80 to the first attachment member 50. The first attachment member 50 is detachably attached to the first link arm 42.

  The first link arm 42 includes a first base member side portion 44 and a first movable member side portion 46. The first base member side portion 44 is a portion of the first link arm 42 that is close to the base member 22. The first movable member side portion 46 is a portion of the first link arm 42 that is close to the movable member 24. The first attachment member 50 is detachably attached to the first base member side portion 44 of the first link arm 42.

  The second link arm 62 includes a second attachment member 70 (see FIG. 2). The second attachment member 70 is a member for attaching the urging member 80 to the link mechanism 40. The other end 86 of the urging member 80 is attached to the second attachment member 70 (see FIG. 3). In one example, the biasing member 80 is attached to the second link arm 62 by attaching the other end 86 of the biasing member 80 to the second attachment member 70. The second attachment member 70 is detachably attached to the second link arm 62.

  The second link arm 62 includes a second base member side portion 64 and a second movable member side portion 66. The second base member side portion 64 is a portion near the base member 22 in the second link arm 62. The second movable member side portion 66 is a portion near the movable member 24 in the second link arm 62. The second attachment member 70 is detachably attached to the second movable member side portion 66 of the second link arm 62.

  The link mechanism 40 further includes a first link pin 48A and a second link pin 48B. The first link pin 48 </ b> A connects the base member 22 and the link mechanism 40. One example of the number of first link pins 48A is two. One first link pin 48 </ b> A connects the base member 22 and the first link arm 42. The other first link pin 48 </ b> A connects the base member 22 and the second link arm 62. The second link pin 48B connects the movable member 24 and the link mechanism 40. An example of the number of second link pins 48B is two. One second link pin 48 </ b> B connects the movable member 24 and the first link arm 42. The other second link pin 48 </ b> B connects the movable member 24 and the second link arm 62. Each link pin 48 </ b> A, 48 </ b> B rotates about its center axis, whereby the movable member 24 moves relative to the base member 22.

  The exterior transmission 20 further includes a motor unit 90. The motor unit 90 transmits a driving force for moving the movable member 24 relative to the base member 22 to the link mechanism 40. The motor unit 90 is configured to rotate the first link pin 48A or the second link pin 48B. In one example, the motor unit 90 is configured to rotate the other first link pin 48 </ b> A that connects the base member 22 and the second link arm 62.

  The motor unit 90 includes a housing 92, a motor 94, and a transmission mechanism 96. The housing 92 is fixed to the base member 22, for example. The motor 94 is housed in the housing 92 and is driven by power supplied from the power supply unit 98 such as a battery via the power line 100. In one example, the motor 94 is driven according to the operation of the speed change device. The shift operation device and the exterior transmission 20 are configured to be able to perform wired communication or wireless communication. The transmission mechanism 96 transmits the driving force of the motor 94 to the link mechanism 40. The transmission mechanism 96 includes, for example, a plurality of gears (not shown). The biasing member 80 has a function of removing the backlash of the transmission mechanism 96. The driving force of the motor 94 is transmitted to the other first link pin 48A via the transmission mechanism 96, and the other link pins 48A and 48B rotate together with the other first link pin 48A, so that the movable member 24 becomes the base member 22. Move against. Thereby, the gear ratio of the bicycle 10 is changed.

A specific configuration of the link mechanism 40 will be described with reference to FIGS. 2 and 3.
As shown in FIG. 2, the first attachment member 50 includes a first shaft-like portion 52. The first shaft portion 52 is a portion to which the urging member 80 can be attached. The first shaft portion 52 includes a first end portion 54 and a second end portion 58. The first end portion 54 includes a tool engaging portion 54A. The tool engaging portion 54A is a portion with which a tool can be engaged. In one example, the tool engaging portion 54A is a hexagonal hole into which a hexagonal bar spanner can be engaged. The second end portion 58 is an end portion of the first shaft-like portion 52 that is opposite to the first end portion 54.

  The first shaft-like portion 52 includes at least one engaging portion 56. At least one engaging portion 56 is engageable with the first link arm 42. The at least one engaging portion 56 includes a first engaging portion 57 and a second engaging portion 60. The first engaging portion 57 is provided in a portion of the first shaft-like portion 52 that is closer to the first end portion 54 than the second end portion 58. The first engagement portion 57 includes a first screw portion 57A. An example of the first screw portion 57A is a male screw. The second engaging portion 60 is provided in a portion of the first shaft-like portion 52 that is closer to the second end portion 58 than the first end portion 54.

  As shown in FIG. 3, the first link arm 42 includes a third engagement portion 44A and a fourth engagement portion 44C. The third engaging portion 44A and the fourth engaging portion 44C are provided on the first base member side portion 44 of the first link arm 42. The third engagement portion 44 </ b> A can engage with the first engagement portion 57 of the first attachment member 50. The third engagement portion 44A includes a second screw portion 44B. An example of the second screw portion 44B is a female screw that can be engaged with the first screw portion 57A. The fourth engagement portion 44 </ b> C can be engaged with the second engagement portion 60 of the first attachment member 50. The second engaging portion 60 passes through the third engaging portion 44A and is inserted into the fourth engaging portion 44C, and the first engaging portion 57 is screwed to the third engaging portion 44A, whereby the first The attachment member 50 is attached to the first link arm 42.

  As shown in FIG. 2, the second attachment member 70 includes a second shaft-like portion 72. The second shaft portion 72 is a portion to which the urging member 80 can be attached. The second shaft portion 72 includes a first end portion 74 and a second end portion 76. The first end portion 74 includes a tool engaging portion (not shown). A tool engaging part is a part which a tool can engage. In one example, the tool engaging portion is a recess that can be engaged by a driver. The second end portion 76 is an end portion of the second shaft-like portion 72 opposite to the first end portion 74.

  The second shaft portion 72 includes a fifth engagement portion 78. The fifth engaging portion 78 can be engaged with the second link arm 62. The fifth engaging portion 78 is provided in a portion of the second shaft-like portion 72 that is closer to the second end portion 76 than the first end portion 74. The fifth engagement portion 78 includes a third screw portion 78A. An example of the third screw portion 78A is a male screw.

  As shown in FIG. 3, the second link arm 62 includes a sixth engaging portion 68. The sixth engaging portion 68 is provided on the second movable member side portion 66 of the second link arm 62. The sixth engaging portion 68 can be engaged with the fifth engaging portion 78 of the second mounting member 70. The sixth engagement portion 68 includes a fourth screw portion 68A. An example of the fourth screw portion 68A is a female screw that can be engaged with the third screw portion 78A. The second attachment member 70 is attached to the second link arm 62 by screwing the fifth engagement portion 78 to the sixth engagement portion 68.

  The biasing member 80 is a coil spring 82. One end portion 84 of the urging member 80 is provided with a hook 84 </ b> A for attachment to the first attachment member 50. A hook 86 </ b> A for attaching to the second attachment member 70 is provided at the other end 86 of the urging member 80.

  The first mounting member 50 is attached to the first link arm 42 so that one hook 84A of the biasing member 80 is hooked on the first shaft-shaped portion 52, and the other hook 86A of the biasing member 80 is the second shaft-shaped portion. The second attachment member 70 is attached to the second link arm 62 so as to be hooked on 72. For this reason, the biasing member 80 is easily attached to each link arm 42 and 62. Further, the first attachment member 50 is removed from the first link arm 42, and the second attachment member 70 is removed from the second link arm 62. For this reason, the urging member 80 is easily detached from the link arms 42 and 62. As described above, since the urging member 80 can be easily attached to and detached from the link arms 42 and 62, for example, the urging member 80 corresponding to the type of the bicycle 10 can be appropriately selected and used for the link mechanism 40.

(Second Embodiment)
With reference to FIG. 4, the exterior transmission 20 of 2nd Embodiment is demonstrated. About the structure which is common in 1st Embodiment, the code | symbol same as 1st Embodiment is attached | subjected and the overlapping description is abbreviate | omitted.

  As shown in FIG. 4, the link mechanism 40 does not include the urging member 80 (see FIG. 1). In the example shown in FIG. 4, the first attachment member 50 and the second attachment member 70 are omitted from the link mechanism 40. The exterior transmission 20 including the link mechanism 40 that does not include the urging member 80 is attached to, for example, a light vehicle. The exterior transmission 20 may include a movable member 24 that does not include the biasing member 28.

(Modification)
The description regarding each said embodiment is an illustration of the form which the bicycle exterior transmission according to this invention can take, and it does not intend restrict | limiting the form. The bicycle exterior transmission according to the present invention can take a form in which, for example, the modifications of the above-described embodiments described below and at least two modifications not contradicting each other are combined. In the following modified examples, the same reference numerals as those of the respective embodiments are assigned to portions common to those of the respective embodiments, and the description thereof is omitted.

-The 1st axial part 52 can take the form which abbreviate | omitted the 2nd engaging part 60. FIG. In this example, the fourth engagement portion 44C is omitted from the first link arm 42.
The first screw portion 57 </ b> A is provided in the second engagement portion 60 instead of or in addition to the first engagement portion 57. In one example, the first screw portion 57 </ b> A is provided in the second engagement portion 60 instead of the first engagement portion 57. In this example, the second screw portion 44B is provided in the fourth engagement portion 44C instead of the third engagement portion 44A. The first engaging portion 57 may be omitted from the first shaft-like portion 52, and the third engaging portion 44A may be omitted from the first link arm 42.

  -The relationship between the 2nd attachment member 70 and the 2nd link arm 62 can be changed arbitrarily. In one example, the second attachment member 70 is fixed to the second link arm 62. According to this example, in a state where the urging member 80 is detached from the first link arm 42, the urging member 80 is attached to the second link arm 62 by the hook 86A being hooked on the second attachment member 70, The urging member 80 is removed from the second link arm 62 by removing the hook 86 </ b> A from the second attachment member 70. Since the urging member 80 can be easily attached to and detached from the first link arm 42, the urging member 80 can be attached to and detached from the link arms 42 and 62 even when the second mounting member 70 is fixed to the second link arm 62. Becomes easier. The second attachment member 70 may be provided integrally with the second link arm 62.

  The configuration of the motor unit 90 can be arbitrarily changed. In the first example, the motor unit 90 is configured to rotate one first link pin 48 </ b> A that connects the base member 22 and the first link arm 42. In the second example, the motor unit 90 is configured to rotate one second link pin 48 </ b> B that connects the movable member 24 and the first link arm 42. In the third example, the motor unit 90 is configured to rotate the other second link pin 48 </ b> B that connects the movable member 24 and the second link arm 62. In the fourth example, the motor unit 90 is configured to rotate at least two of the two first link pins 48A and the two second link pins 48B.

The exterior transmission 20 can take a form in which the motor unit 90 is omitted. In one example, the exterior transmission 20 and the speed change operation device are connected by a Bowden cable (not shown).
-The form of the exterior transmission 20 can be changed arbitrarily. In one example, the exterior transmission 20 is a front derailleur. In this example, the exterior transmission 20 is provided in the vicinity of the crankshaft of the frame 12 of the bicycle 10. The exterior transmission 20 has a configuration corresponding to the front derailleur in various configurations other than the link mechanism 40.

DESCRIPTION OF SYMBOLS 10 ... Bicycle, 12 ... Frame, 20 ... Bicycle exterior transmission, 20A ... Rear derailleur, 22 ... Base member, 24 ... Movable member, 28 ... Biasing member, 30 ... Chain guide, 40 ... Link mechanism, 42 ... First link Arm 44, first base member side portion, 44A ... third engagement portion, 44C ... fourth engagement portion, 46 ... first movable member side portion, 48A ... first link pin, 48B ... second link pin, DESCRIPTION OF SYMBOLS 50 ... 1st attachment member, 52 ... 1st axial part, 54 ... 1st edge part, 54A ... Tool engagement part, 56 ... Engagement part, 57 ... 1st engagement part, 57A ... 1st thread part, 58 ... 2nd end, 60 ... 2nd engaging part, 62 ... 2nd link arm, 64 ... 2nd base member side part, 66 ... 2nd movable member side part, 68 ... 6th engaging part, 70 ... Second mounting member, 78... Fifth engaging portion, 80. Member, 82 ... coil spring, 84, 86 ... end, 84A, 86A ... hook, 90 ... motor unit, 94 ... motor, 96 ... transmission mechanism.

Claims (20)

A base member attached to the bicycle frame;
A movable member that moves relative to the base member;
A link mechanism for connecting the base member and the movable member;
The link mechanism includes a first link arm and a second link arm that is closer to the frame than the first link arm when the base member is attached to the frame;
The first link arm includes a first attachment member for attaching an urging member for applying an urging force to the link mechanism to the link mechanism,
The bicycle exterior transmission, wherein the first attachment member is detachably attached to the first link arm. The first attachment member includes a first shaft-like portion to which the urging member can be attached,
The bicycle exterior transmission according to claim 1, wherein the first shaft-like portion includes a first end portion and a second end portion opposite to the first end portion.   The bicycle exterior transmission according to claim 2, wherein the first shaft-shaped portion includes at least one engaging portion that can be engaged with the first link arm.   The bicycle exterior transmission according to claim 3, wherein the at least one engagement portion includes a first screw portion.   The bicycle exterior transmission according to claim 4, wherein the first screw portion is provided in a portion of the first shaft-like portion that is closer to the first end portion than the second end portion. The at least one engaging portion includes a first engaging portion provided in a portion closer to the first end portion than the second end portion of the first shaft-like portion, and the first shaft-like portion. Including a second engagement portion provided at a portion closer to the second end than the first end of
The first engagement portion includes a first screw portion,
The bicycle according to claim 3, wherein the first link arm includes a third engagement portion that engages with the first engagement portion, and a fourth engagement portion that engages with the second engagement portion. Exterior transmission.   The bicycle exterior transmission according to any one of claims 2 to 6, wherein the first end portion includes a tool engaging portion with which a tool can be engaged. The second link arm includes a second attachment member for attaching the biasing member to the link mechanism,
The bicycle exterior transmission according to any one of claims 1 to 7, wherein the second attachment member is detachably attached to the second link arm. The second mounting member includes a fifth engaging portion,
The bicycle exterior transmission according to claim 8, wherein the second link arm includes a sixth engagement portion that engages with the fifth engagement portion. The first link arm includes a first base member side portion close to the base member and a first movable member side portion close to the movable member;
The second link arm includes a second base member side portion close to the base member and a second movable member side portion close to the movable member;
The first attachment member is detachably attached to the first base member side portion of the first link arm,
The bicycle exterior transmission according to claim 8 or 9, wherein the second attachment member is detachably attached to the second movable member side portion of the second link arm. One end of the biasing member is attached to the first attachment member,
The bicycle exterior transmission according to any one of claims 8 to 10, wherein the other end of the biasing member is attached to the second attachment member.   The bicycle exterior transmission according to claim 11, wherein the link mechanism further includes the biasing member. The biasing member is a coil spring;
The bicycle exterior transmission according to claim 12, wherein a hook for attachment to the first attachment member is provided at the one end.   The bicycle exterior transmission according to any one of claims 1 to 13, further comprising a motor unit for moving the movable member relative to the base member.   The bicycle exterior transmission according to claim 14, wherein the motor unit includes a motor and a transmission mechanism that transmits a driving force of the motor to the link mechanism. A base member attached to the bicycle frame;
A movable member that moves relative to the base member;
A chain guide rotatably attached to the movable member;
A link mechanism for connecting the base member and the movable member;
A motor unit for moving the movable member relative to the base member,
The motor unit includes a motor and a transmission mechanism that transmits the driving force of the motor to the link mechanism,
The link mechanism includes a first link pin that connects the base member and the link mechanism, and a second link pin that connects the movable member and the link mechanism,
The motor unit is configured to rotate the first link pin or the second link pin,
The movable member includes a biasing member that biases the chain guide,
The link mechanism is a bicycle exterior transmission that does not include an urging member. The link mechanism includes a first link arm and a second link arm,
The bicycle exterior transmission according to claim 16, wherein the first link arm is located farther from the frame than the second link arm when the base member is attached to the frame. A base member attached to the bicycle frame;
A movable member that moves relative to the base member;
A link mechanism for connecting the base member and the movable member;
A motor unit for moving the movable member relative to the base member,
The motor unit includes a motor and a transmission mechanism that transmits the driving force of the motor to the link mechanism,
The link mechanism includes a first link pin that connects the base member and the link mechanism, and a second link pin that connects the movable member and the link mechanism,
The motor unit is configured to rotate the first link pin or the second link pin,
A bicycle exterior transmission that does not include a biasing member that biases the link mechanism. The link mechanism includes a first link arm and a second link arm,
The bicycle exterior transmission according to claim 18, wherein the first link arm is located farther from the frame than the second link arm when the base member is attached to the frame. The bicycle exterior transmission according to any one of claims 1 to 19, which is a rear derailleur.