An automatic bicycle drive train shifting apparatus comprising a bicycle drive chain derailer powered by a servo gearmotor slaved to an electronic control system and controlled through a highly adaptable user interface serving to automatically alternate drive chain position between available bicycle drive sprockets under user defined shifting criteria adaptable in real time to rider conditioning, comfort level and road conditions thereby alleviating manual shifting tasks and achieving optimal pedal rate and effort settings for the rider.

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.

A bicycle rear derailleur is provided, including a mounting portion; a linkage mechanism, pivoted to the mounting portion and having an extension portion having a cable fixing point and being located at an inner position relative to an outer side of the linkage mechanism; a guiding mechanism, pivoted to the linkage mechanism and being rotatable about an axis, the guiding mechanism including a first pulley defining a pulley plane and a second pulley, an extension line which is perpendicular to the axis and an axial extension line of the second pulley being defined as a first reference line; wherein when the bicycle rear derailleur is located on an initial position, the cable fixing point is between the first reference line and the mounting portion, and the cable fixing point dose not cross the pulley plane during gearshift of the bicycle rear derailleur relative to rear sprockets.

A bicycle rear derailleur includes a base member having a first portion and a second portion. The first portion of the base member is mountable to a bicycle frame, and the second portion of the base member is attached to the first portion of the base member and includes at least a portion of a power supply attachment. The bicycle rear derailleur also includes a movable member movably coupled to the first portion of the base member and electrically connected to the second portion of the base member. The bicycle rear derailleur includes a chain guide assembly rotatably connected to the movable member.

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

A bicycle rear derailleur includes a base member, a chain guide, a movable member and a first link member. The base member is configured to be mounted to a bicycle frame at a frame mounting axis. The chain guide includes a first pulley rotatably arranged around a first pulley axis in a first pulley plane. The movable member pivotally supports the chain guide about a pivot axis. The first link member moves the chain guide between first and second lateral positions. The first lateral position is closer to a bicycle center plane. The first pulley plane intersects the first link member in a state where the chain guide is located at the second lateral position. The frame mounting axis is spaced from the pivot axis by a distance equal to or larger than eighty-nine millimeters when the chain guide is at the first lateral position.

A bicycle rear derailleur includes a base member, a chain guide, a movable member and a first link member. The base member is configured to be mounted to a bicycle frame at a frame mounting axis. The chain guide includes a first pulley rotatably arranged around a first pulley axis in a first pulley plane. The movable member pivotally supports the chain guide about a pivot axis. The first link member moves the chain guide between first and second lateral positions. The first lateral position is closer to a bicycle center plane. The first pulley plane intersects the first link member in a state where the chain guide is located at the second lateral position. The frame mounting axis is spaced from the pivot axis by a distance equal to or larger than eighty-nine millimeters when the chain guide is at the first lateral position.

A bicycle derailleur is basically provided with a base member, a movable member, a link structure and a cable interactive structure. The link structure is configured to movably connect the movable member relative to the base member. The cable interactive structure is provided on the link structure. The cable interactive structure includes a chain barrier portion. The chain barrier portion is configured to prevent a chain from contacting the link structure.