The disclosure relates to a derailleur for a bicycle, comprising a B-knuckle assembly which is designed for mounting on the bicycle frame, a P-knuckle assembly, a parallelogram assembly via which the B-knuckle assembly and the P-knuckle assembly are movably connected to one another, a cage assembly in which a chain guide pulley and a chain tension pulley are rotatably held, where the cage assembly is mounted on the P-knuckle assembly so as to be rotatable about a P axis, and an rotation angle detection device which is designed to detect and/or display an angle of rotation between the P-knuckle assembly and the cage assembly.

A bicycle rear derailleur is configured to be mounted on a wheel shaft on a bicycle frame. The bicycle rear derailleur includes a base component, a movable component, a linkage assembly, a chain guide, and a mount assembly. The base component is configured to be mounted on the bicycle frame. Two opposite ends of the linkage assembly are pivotally disposed on the base component and the movable component respectively. The chain guide is pivotally disposed on the movable component. The mount assembly includes an adapter, a bushing, and a fastener. The adapter is configured to be fixed on the bicycle frame. The base component is stacked on the adapter. The bushing is configured to be disposed through the bicycle frame, the adapter and the base component and is configured for an insertion of the wheel shaft. The fastener is fastened on the bushing.

A bicycle rear derailleur is configured to be mounted on a wheel shaft on a bicycle frame. The bicycle rear derailleur includes a base component, a movable component, a linkage assembly, a chain guide, and a mount assembly. The base component is configured to be mounted on the bicycle frame. Two opposite ends of the linkage assembly are pivotally disposed on the base component and the movable component respectively. The chain guide is pivotally disposed on the movable component. The mount assembly includes an adapter, a bushing, and a fastener. The adapter is configured to be fixed on the bicycle frame. The base component is stacked on the adapter. The bushing is configured to be disposed through the bicycle frame, the adapter and the base component and is configured for an insertion of the wheel shaft. The fastener is fastened on the bushing.

A rear sprocket assembly comprises a first sprocket, a second sprocket, and at least one tooth-position maintaining member. The at least one tooth-position maintaining member is configured to maintain a relative position between a plurality of first sprocket teeth and a plurality of second sprocket teeth in a circumferential direction with respect to a rotational center axis. The at least one tooth-position maintaining member includes a fixed portion and at least one guide portion. The fixed portion is configured to be fixed to one of the first sprocket and the second sprocket. The at least one guide portion is configured to engage with the other of the first sprocket and the second sprocket such that the other of the first sprocket and the second sprocket is slidable relative to the one of the first sprocket and the second sprocket in the axial direction.

A rear sprocket assembly comprises a first sprocket, a second sprocket, and at least one tooth-position maintaining member. The at least one tooth-position maintaining member is configured to maintain a relative position between a plurality of first sprocket teeth and a plurality of second sprocket teeth in a circumferential direction with respect to a rotational center axis. The at least one tooth-position maintaining member includes a fixed portion and at least one guide portion. The fixed portion is configured to be fixed to one of the first sprocket and the second sprocket. The at least one guide portion is configured to engage with the other of the first sprocket and the second sprocket such that the other of the first sprocket and the second sprocket is slidable relative to the one of the first sprocket and the second sprocket in the axial direction.

A bicycle rear derailleur includes a base member including a mounting portion configured to be attached to a bicycle frame, the mounting portion having a mounting opening through which a central axis of a hub axle passes in a mounting state of the bicycle rear derailleur. The mounting portion includes a single joint or is free of any joint. Also included is a movable member movably coupled relative to the base member and a linkage structure operatively connecting the movable member to the base member. Also included is at least one of a motor, a first wireless communication unit, and an electrical connector. The at least one of the motor, the first wireless communication unit, and the electrical connector are disposed on at least one of the base member, the movable member, and the linkage structure.

A rear derailleur of a bicycle includes a fixing portion connected to a frame of the bicycle, a linkage assembly pivotally connected between the fixing portion and the moving portion, a moving portion pivotally connected to the linkage assembly, a chain guide assembly connected to the moving portion, and a driving assembly including a clutch assembly, a motor, and a driving gear assembly connected to the clutch assembly. The clutch assembly is disposed between the fixing portion and the linkage assembly and includes a first clutch member and a second clutch member. When a relative rotational torque between the first clutch member and the second clutch member is greater than a predetermined resistance, the first clutch teeth and the second clutch teeth shift relatively. Thereby, the driving gear assembly or the output shaft of the motor could be prevented from damaging.

A rear derailleur of a bicycle includes a fixing portion connected to a frame of the bicycle, a linkage assembly pivotally connected between the fixing portion and the moving portion, a moving portion pivotally connected to the linkage assembly, a chain guide assembly connected to the moving portion, and a driving assembly including a clutch assembly, a motor, and a driving gear assembly connected to the clutch assembly. The clutch assembly is disposed between the fixing portion and the linkage assembly and includes a first clutch member and a second clutch member. When a relative rotational torque between the first clutch member and the second clutch member is greater than a predetermined resistance, the first clutch teeth and the second clutch teeth shift relatively. Thereby, the driving gear assembly or the output shaft of the motor could be prevented from damaging.

A bicycle gearshift mechanism has a base element, a pivot mechanism, a movable element, and a chain guide arrangement. The pivot mechanism connects the base element to the movable element. The chain guide arrangement is connected, rotatably about a rotary axle, to the movable element. The base element comprises a first attachment end, which is coaxial with respect to the rear-wheel axle or axis, and a second attachment end for coupling to the pivot mechanism.

A bicycle gearshift mechanism has a base element, a pivot mechanism, a movable element, and a chain guide arrangement. The pivot mechanism connects the base element to the movable element. The chain guide arrangement is connected, rotatably about a rotary axle, to the movable element. The base element comprises a first attachment end, which is coaxial with respect to the rear-wheel axle or axis, and a second attachment end for coupling to the pivot mechanism.