An embodiment of the invention provides an electromechanical rear derailleur for a bicycle including a base member that is configured to be coupled to a frame member of a bicycle. The derailleur includes a movable member and a link mechanism that movably couples the movable member to the base member. A motor is positioned at the movable member to move the movable member.

A bicycle gearshift including a first body associated with a bicycle frame, a second body connected to, and moveable relative to, the first body, a rocker arm rotatably connected to the second body at a rotation axis, and a shaft extending coaxially to this axis and fixedly associated with the rocker arm. A unidirectional rotation device is arranged between the shaft and second body to allow rotation of the shaft relative to the second body only in a first rotation direction. An elastic element is associated with the second body and the rocker arm to push the rocker arm in rotation about the axis in the first rotation direction. A damping device is arranged between the shaft and unidirectional rotation device to generate a friction force when the rocker arm is rotated in a second, opposite rotation direction, and has a friction surface in contact with the unidirectional rotation device.

A linkage having a link arm including a first link and a second link. The first link includes a first hole and a second hole. The second link includes a third hole and a fourth hole. The first link and the second link are pivotally coupled to a first member about a first pivot axis, and are pivotally coupled to a second member about a second pivot axis spaced apart from the first pivot axis. The first hole and the third hole are provided coaxially with the first pivot axis. The second hole and the fourth hole are provided coaxially with the second pivot axis. The third hole is provided between the first hole and the first member in an axial direction with respect to the first pivot axis in a state where the first link is pivotally coupled to the first member about the first pivot axis.

A linkage having a link arm including a first link and a second link. The first link includes a first hole and a second hole. The second link includes a third hole and a fourth hole. The first link and the second link are pivotally coupled to a first member about a first pivot axis, and are pivotally coupled to a second member about a second pivot axis spaced apart from the first pivot axis. The first hole and the third hole are provided coaxially with the first pivot axis. The second hole and the fourth hole are provided coaxially with the second pivot axis. The third hole is provided between the first hole and the first member in an axial direction with respect to the first pivot axis in a state where the first link is pivotally coupled to the first member about the first pivot axis.

An electrical actuator for a bicycle rear derailleur making use of a standard wireless remote control (RC) servo unit relying exclusively on highly efficient spur gearing reduction and facilitating highly accurate derailleur positioning thereof through an integral digital magnetic rotary encoder with assembly thereof sealed in a two-piece housing with a lateral extension for an auxiliary spur gear serving to transmit actuation effort thereof to actuation shaft of a rear derailleur.

A derailleur basically includes a base member, a movable member and a linkage assembly. The base member includes a first base member connecting section and a second base member connecting section. The movable member includes a first movable member connecting section and a second movable member connecting section. The linkage assembly includes an inner link member and an outer link member. The outer link is pivotally coupled to the second base member connecting section about a third pivot axis. The outer link is pivotally coupled to the second movable member connecting section about a fourth pivot axis. The outer link member has a power source receiving part that is configured to be arranged such that the power source receiving part traverses a reference line extending between the third pivot axis and the fourth pivot axis.

A rear derailleur is provided, including: a base, configured to be mounted to a bicycle; a movable member, movably disposed on the base; a shaft, rotatably connected to the movable member; a chain guide, connected to the shaft; a biasing member, disposed between the chain guide and the movable member; a resistance mechanism, connected to the movable member to apply frictional resistance to the shaft.

A rear gearshift mechanism for installation on a bicycle frame coaxial with a rear-wheel axis has a base element, a pivot mechanism, a movable element and a chain guide. The base element includes an attachment end for installation on the bicycle frame. A first arm and a second arm of the attachment end are arranged spaced apart from one another in an axial direction and, by an associated adapter which has a thread, are configured for the installation of the gearshift mechanism on an associated bracket portion, in particular a dropout or frame hanger. The first arm is arranged on an inner side of the bracket portion, and the second arm is arranged on an outer side of the bracket portion. The base element is designed with a setting device by which the base element can be pivoted in a chain tensioning direction.

A bicycle gearshift is operated by imposing on the chain guide a primary displacement in the axial direction with respect to a cogset, to move the chain between the sprockets. Simultaneously with imposing on the primary displacement imposing on the chain guide a secondary displacement in the radial direction with respect to the cogset. The secondary displacement is of a greater size when the primary displacement takes place in the area of the cogset with the larger sprockets whereas it is of a smaller size when the primary displacement takes place in the area of the cogset with the smaller sprockets.

A bicycle rear derailleur comprises a base member, a linkage structure, a movable member, a first pulley assembly, and a second pulley assembly. The first pulley assembly includes a first pulley support and a first toothed pulley. The first pulley support is pivotally coupled to the movable member about a first pivot axis. The first toothed pulley is rotatably coupled to the first pulley support about a first pulley axis spaced apart from the first pivot axis. The second pulley assembly includes a second pulley support, a second toothed pulley, and a third toothed pulley. The second pulley support is pivotally coupled to the movable member about a second pivot axis. The second toothed pulley is rotatably coupled to the second pulley support about a second pulley axis. The third toothed pulley is rotatably coupled to the second pulley support about a third pulley axis.