The derailleur has a damper that breaks the angular movements of a chain guide. Variable volume chambers in the damper are filled with a damping fluid and connected through a controlled fluid passage system so that fluid flows between chambers in response to angular movement of the chain guide. The damper comprises a dividing body in a mobile body coaxial to the axis X, mechanically constrained so that each rotation of the dividing body about the axis X is accompanied by a translation of the dividing body along the axis X. The dividing body is mechanically constrained to the chain guide and moves with it in the angular direction about the axis X. The chambers are formed in the mobile body on opposite sides of the dividing body and change volume in opposite directions when the dividing body moves along the axis X.

A bicycle rear derailleur includes a movable member and a chain guide assembly rotatably connected to the movable member. The bicycle rear derailleur also includes a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface, a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member, and a damper device disposed between the chain guide assembly and the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member. The damper device includes a friction device that is radially inner relative to the biasing device. The friction device includes a friction member having at least one friction surface biased against and in frictional engagement with the pivot member.

A bicycle rear derailleur includes a movable member and a chain guide assembly rotatably connected to the movable member. The bicycle rear derailleur also includes a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface, a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member, and a damper device disposed between the chain guide assembly and the movable member. The damper device is operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member. The damper device includes a friction device that is radially inner relative to the biasing device. The friction device includes a friction member having at least one friction surface biased against and in frictional engagement with the pivot member.

A bracket apparatus for mounting a derailleur to a frame of a human-powered vehicle comprises a bracket body and one of a restriction member and a restriction opening. The bracket body includes a frame attachment portion configured to be attached to the frame of the human-powered vehicle and a derailleur attachment portion to which the derailleur is to be attached. The restriction member is configured to be at least partly provided in the restriction opening to restrict a rotation of the bracket body relative to the frame of the human-powered vehicle in a bracket mounting state where the bracket apparatus is mounted to the frame of the human-powered vehicle.

A bracket apparatus for mounting a derailleur to a frame of a human-powered vehicle comprises a bracket body and one of a restriction member and a restriction opening. The bracket body includes a frame attachment portion configured to be attached to the frame of the human-powered vehicle and a derailleur attachment portion to which the derailleur is to be attached. The restriction member is configured to be at least partly provided in the restriction opening to restrict a rotation of the bracket body relative to the frame of the human-powered vehicle in a bracket mounting state where the bracket apparatus is mounted to the frame of the human-powered vehicle.

A bicycle rear derailleur includes a seat assembly, a movable component, a linkage assembly, and a chain guide. The seat assembly includes a first seat body, a second seat body, and a shaft. The shaft is disposed through the first seat body and the second seat body and configured to be mounted on the bicycle frame, and the second seat body is configured to connect the first seat body with the bicycle frame. The linkage assembly connects the movable component with the first seat body. The chain guide is pivotably disposed on the movable component. The first seat body is movable towards or away from the second seat body along a central line of the shaft.

A bicycle rear derailleur includes a seat assembly, a movable component, a linkage assembly, and a chain guide. The seat assembly includes a first seat body, a second seat body, and a shaft. The shaft is disposed through the first seat body and the second seat body and configured to be mounted on the bicycle frame, and the second seat body is configured to connect the first seat body with the bicycle frame. The linkage assembly connects the movable component with the first seat body. The chain guide is pivotably disposed on the movable component. The first seat body is movable towards or away from the second seat body along a central line of the shaft.

A bicycle derailleur pulley comprises a bearing region rotatable about an axis of rotation, a tooth region with teeth formed thereon for engaging into the chain, and a supporting structure that connects the bearing region and the tooth region. On at least one tooth of the chain-guiding pulley, on each of the inboard-side and outboard-side side surfaces thereof, there are formed guide regions for lateral guidance of the chain substantially parallel to the axis of rotation. At least one inboard-side guide region of the at least one tooth has an at least regionally reduced thickness dimension, relative to a central plane of the chain-guiding pulley, in relation to at least one outboard-side guide region, such that a chain section running substantially tangentially off the chain-guiding pulley can assume a greater skew angle in an outboard direction than in an inboard direction.

A bicycle derailleur pulley comprises a bearing region rotatable about an axis of rotation, a tooth region with teeth formed thereon for engaging into the chain, and a supporting structure that connects the bearing region and the tooth region. On at least one tooth of the chain-guiding pulley, on each of the inboard-side and outboard-side side surfaces thereof, there are formed guide regions for lateral guidance of the chain substantially parallel to the axis of rotation. At least one inboard-side guide region of the at least one tooth has an at least regionally reduced thickness dimension, relative to a central plane of the chain-guiding pulley, in relation to at least one outboard-side guide region, such that a chain section running substantially tangentially off the chain-guiding pulley can assume a greater skew angle in an outboard direction than in an inboard direction.

A rocker for a bicycle gear that has an inner plate, an outer plate, a pair of pins integral with said inner and outer plates and a pair of toothed wheels arranged between them. Each toothed wheels is rotatably mounted on a respective pin. At least one pin is inserted in non-threaded through holes formed in the inner and outer plates and is defined by a screw with an outer threading and a female screw with an inner threading engaged with the outer threading.