A rear derailleur of a bicycle is disclosed. The rear derailleur includes a four-bar linkage. A fixing pin is received in a blind inner cavity of a base body and a fixing screw is constrained to a frame. A spring loading insert is arranged in the blind inner cavity. The base body is rotatable with respect to the spring loading insert. Connection members are inserted in seats formed on the fixing screw and on the spring loading insert to axially constrain the fixing screw and the spring loading insert. A toothed sector is mounted coaxially to the spring loading insert and is active on a sprocket which is active on the base body. A torsion spring is active between the spring loading insert and the toothed sector and is configured to constrain the spring loading insert and the toothed sector in rotation during controlled movements of the chain guide.

A bicycle derailleur includes following features. A chain guiding portion is adapted to be engaged with a bicycle chain and is adapted to guide a drive direction of the bicycle chain. A connecting portion is connected to a fixed portion and the chain guiding portion. A movable portion is pivotally connected to the connecting portion and the chain guiding portion. The movable portion includes a pressing member, a base, and a sprag clutch. The sprag clutch is disposed between the pressing member and the base. The pivot shaft is connected to the movable portion and the chain guiding portion, and is rotatably disposed through the pressing member, the sprag clutch and the base. The sprag clutch is driven to rotate when the pivot shaft rotates along the direction. The pressing member is adapted to press the sprag clutch to increase rotational resistance of the chain guiding portion.

A bicycle derailleur includes a base member, a movable member, a link member, a chain guide, a biasing mechanism and a switching member. The link member movably couples the movable member to the base member. The chain guide is pivotally coupled to the movable member about a pivot axis. The biasing mechanism is operatively disposed between the movable member and the chain guide, and biases the chain guide with respect to the movable member about the pivot axis in a first direction in a biasing state. The switching member is configured to selectively switch the biasing mechanism between the biasing state and a releasing state. The biasing mechanism biases the chain guide less in the releasing state than the biasing state. The switching member is disengaged from the biasing mechanism in the biasing state. The switching member is engaged with the biasing mechanism in the releasing state.

A rear derailleur is configured as a hierarchical, at least two-level modular construction system and comprises at least several of the modules: base element module, swivel formation module, shifting element module, and chain guiding device module. At least one of the modules is replaceable and handleable in one piece. At least one of the modules includes at least one sub-assembly that is replaceable and handleable in one piece. In an embodiment the modular construction system is configured to use at least one family of sub-assemblies comprising at least two family members within at least one of the modules.

Detachable connection interfaces of the family members to adjacent sub-assemblies of the module within the sub-assembly family are configured uniformly across family members for the respective sub-assembly family in such a way that a family member of the sub-assembly family of the module is exchangeable for another family member of the same sub-assembly family that, is for example, of different material, of different design, of different functionality or has different surface properties, while retaining the remaining sub-assemblies of the module.

An electrical bicycle derailleur includes a base member and a movable member movably arranged between a retracted position and an extended position. A linkage operatively couples the movable member to the base member. The linkage includes a first link member and a second link member. The first link member is disposed closer to the base member than the second link member. A motor unit is operatively coupled to the first and second link members to rotate the first and second link members. A linkage housing is configured to support the first and second link members and the motor unit. A first diameter of the first link member is different from a second diameter of the second link member and/or a first tooth number of the first link member is different from a second tooth number of the second link member.

An electrical bicycle derailleur includes a base member and a movable member movably arranged between a retracted position and an extended position. A linkage operatively couples the movable member to the base member. The linkage includes a first link member and a second link member. The first link member is disposed closer to the base member than the second link member. A motor unit is operatively coupled to the first and second link members to rotate the first and second link members. A linkage housing is configured to support the first and second link members and the motor unit. A first diameter of the first link member is different from a second diameter of the second link member and/or a first tooth number of the first link member is different from a second tooth number of the second link member.

A derailleur may include an electric motor configured to drive a gear assembly to pivot a rigid case around the B knuckle of the derailleur. A chain tensioner-supporting P knuckle of the derailleur may be pivotably connected to the rigid case. The P knuckle may be held substantially parallel to an associated bicycle frame by a belt that is fixed to the B knuckle shaft and passes around the P knuckle shaft. A belt tensioner may be provided between the B knuckle and P knuckle shafts.

A derailleur basically includes a base member, a movable member, a linkage assembly, a power source receiving part and a cover member. The power source receiving part is provided to at least one of the base member, the movable member and the linkage assembly. The power source receiving part receives a power source. The cover member is movable in a first direction to switch from a cover detachment state and a cover attachment state in which the cover member at least partially covers the power source receiving part. The cover member includes first and power source contact surfaces. The first power source contact surface contacts the power source in a holding state where the power source is held in the power source receiving part. The second power source contact surface contacts the power source during an operation for moving the cover member in the first direction.

A bicycle derailleur includes a base member mountable to a bicycle frame and having first and second laterally spaced mounting portions defining first and second planes, and a space therebetween dimensioned to receive a portion of the bicycle frame. A first mounting arrangement defines a first pivot axis oriented at an acute angle relative to the first and second planes. A second mounting arrangement defines a second pivot axis parallel to the first pivot axis. A first link is pivotally connected to the first mounting arrangement and a second link is pivotally connected to the second mounting arrangement. A moveable member is pivotally connected to the first and second links. A battery may be mounted on the base member and electrically connected with a motor carried by the moveable member.

A bicycle derailleur includes a base member mountable to a bicycle frame and a cage assembly moveably coupled to the base member. One or both of a motor and/or electrical generator system may be coupled to and moveable with the cage assembly. The motor is operable to move the cage assembly. The electrical generator system includes a generator and a generator drive system. An energy storage device, spaced apart from the cage assembly, may be connected to the electrical generator system and/or motor with a flexible electrical conductor.