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 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 derailleur apparatus for controlling bicycle speed includes a bicycle chain guide and a pair of moldable wires. The guide has opposite sides receiving a bicycle chain therebetween and is pivotally movable in a lateral direction toward and away from a bicycle frame portion mounting the guide. The moldable wires, disposed side-by-side and spaced apart, are mounted to the bicycle frame portion and have respective outer end portions attached to one guide side. By applying a predetermined electric current to the moldable wires at separate times their outer end portions deform from pliable states to respective acute and obtuse angular shapes relative to respective main portions thereof and thereby move the guide to shift the bicycle chain into engagement with one or the other of inner and outer derailleur sprocket gears of different diameter sizes to change the bicycle speed relative to the pedal cadence of a rider.

A bicycle derailleur apparatus for controlling bicycle speed includes a bicycle chain guide and a pair of moldable wires. The guide has opposite sides receiving a bicycle chain therebetween and is pivotally movable in a lateral direction toward and away from a bicycle frame portion mounting the guide. The moldable wires, disposed side-by-side and spaced apart, are mounted to the bicycle frame portion and have respective outer end portions attached to one guide side. By applying a predetermined electric current to the moldable wires at separate times their outer end portions deform from pliable states to respective acute and obtuse angular shapes relative to respective main portions thereof and thereby move the guide to shift the bicycle chain into engagement with one or the other of inner and outer derailleur sprocket gears of different diameter sizes to change the bicycle speed relative to the pedal cadence of a rider.

An electronic cable puller for a bicycle includes a housing, a drive supported by the housing, and an adjuster connected to the housing. The drive is powerable by a power source and is configured to pull the shift cable into or allow the shift cable to be pulled out of the electronic cable puller. The adjuster is configured to adjust a length of the shift cable relative to a sheath.