A bicycle front derailleur that is movable between shift positions in association with an indexer. The inner mechanical end stop is adjusted at the first indexing position so there is no loosening of the control cable in the last downward gearshifting operation, with the benefit of an immediate and rapid response in the first upward gearshifting operation. The outer end stop is adjusted to interrupt the rotation of the cable-winding bush before it reaches the last indexing position. This pair of mechanical end stops limits the excursion of the derailleur to prevent it being able to shift the chain too much towards the frame or too much away from the frame, which ensures that the chain is not shifted beyond the gears.

A bicycle front derailleur that is movable between shift positions in association with an indexer. The inner mechanical end stop is adjusted at the first indexing position so there is no loosening of the control cable in the last downward gearshifting operation, with the benefit of an immediate and rapid response in the first upward gearshifting operation. The outer end stop is adjusted to interrupt the rotation of the cable-winding bush before it reaches the last indexing position. This pair of mechanical end stops limits the excursion of the derailleur to prevent it being able to shift the chain too much towards the frame or too much away from the frame, which ensures that the chain is not shifted beyond the gears.

A device for actuating a bicycle front derailleur and displacing a transmission chain between toothed wheels of different diameters. An indexer associated with the derailleur comprises a first stop position and a second stop position. The first stop corresponds to engagement of the transmission chain on a first toothed wheel and the second stop position corresponds to engagement of the transmission chain on a different toothed wheel. A control lever operatively active on the indexer switches between the stop positions with a single actuation of the control lever.

A device for actuating a bicycle front derailleur and displacing a transmission chain between toothed wheels of different diameters. An indexer associated with the derailleur comprises a first stop position and a second stop position. The first stop corresponds to engagement of the transmission chain on a first toothed wheel and the second stop position corresponds to engagement of the transmission chain on a different toothed wheel. A control lever operatively active on the indexer switches between the stop positions with a single actuation of the control lever.

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 sprocket for engagement with a drive chain has a plurality of teeth extending radially from a periphery of the sprocket, including a first and a second group of teeth; the teeth of the first group and the second group are alternately arranged so that each tooth of the first group is followed by a tooth of the second group, and vice versa; each tooth of the first group having a first maximum width, each tooth of the second group having a second maximum width which is larger than the first maximum width; each tooth of the second group has a protrusion on at least one lateral face of the tooth; the outer lateral face of the protrusion extends over a first portion of the lateral face of each tooth of the second group, the length being 50% of the length of the respective tooth or less.

A sprocket for engagement with a drive chain has a plurality of teeth extending radially from a periphery of the sprocket, including a first and a second group of teeth; the teeth of the first group and the second group are alternately arranged so that each tooth of the first group is followed by a tooth of the second group, and vice versa; each tooth of the first group having a first maximum width, each tooth of the second group having a second maximum width which is larger than the first maximum width; each tooth of the second group has a protrusion on at least one lateral face of the tooth; the outer lateral face of the protrusion extends over a first portion of the lateral face of each tooth of the second group, the length being 50% of the length of the respective tooth or less.

A bicycle front shifting system includes operable to transmit a wireless signal, a crank assembly with two crank arms and a pedal on each of the two crank arms. The crank assembly is rotatable about a rotation axis. A front shift unit is coupled to the crank assembly and is rotatable about the rotation axis. The front shift unit includes a chain ring component with a big chain ring and a small chain ring. The small chain ring has a small diameter and the big chain ring has a big diameter that is larger than the small diameter. A shift mechanism is coupled to and rotatable with the chain ring component about the rotation axis. The shift mechanism is configured to receive the wireless signal from the shifter and to shift a chain between the big chain ring and the small chain ring according to the wireless signal.

A sprocket for engagement with a drive chain has a first and a second group of teeth, wherein the teeth of the first group and the second group are alternately arranged and each tooth of the second group is wider than each tooth of the first group. The profile of each tooth of the second group has a first protrusion in the front half of the tooth on a first lateral surface and a second protrusion in the rear half of the tooth on a second, opposite lateral surface of the tooth. In particular, the portion of each tooth of the second group engaging the chain may have a center plane that is rotated or twisted during forming about the radial center line of the tooth with respect to the central plane of the sprocket.

A bicycle front shifting system includes operable to transmit a wireless signal, a crank assembly with two crank arms and a pedal on each of the two crank arms. The crank assembly is rotatable about a rotation axis. A front shift unit is coupled to the crank assembly and is rotatable about the rotation axis. The front shift unit includes a chain ring component with a big chain ring and a small chain ring. The small chain ring has a small diameter and the big chain ring has a big diameter that is larger than the small diameter. A shift mechanism is coupled to and rotatable with the chain ring component about the rotation axis. The shift mechanism is configured to receive the wireless signal from the shifter and to shift a chain between the big chain ring and the small chain ring according to the wireless signal.