A bicycle electric/electronic derailleur has a plurality of mutually movable components: a support body configured to be attached to a bicycle frame, a chain guide, and a pair of connecting arms, for connection between the support body and the chain guide at respective geometric articulation axes. A geared motor controls the motion of the plurality of mutually movable components. At least one first component has a case with a chamber containing the geared motor and/or one or more electric/electronic devices. The chamber crosses at least one articulation axis. The case comprises a blind hole that is coaxial with the one axis and open outwards of the case. A second component has a pivot pivotable in the blind hole.

A bicycle electric/electronic derailleur has a plurality of mutually movable components: a support body configured to be attached to a bicycle frame, a chain guide, and a pair of connecting arms, for connection between the support body and the chain guide at respective geometric articulation axes. A geared motor controls the motion of the plurality of mutually movable components. At least one first component has a case with a chamber containing the geared motor and/or one or more electric/electronic devices. The chamber crosses at least one articulation axis. The case comprises a blind hole that is coaxial with the one axis and open outwards of the case. A second component has a pivot pivotable in the blind hole.

A bicycle rear derailleur includes a limiter assembly arranged between (i) a first component selected between the support body and the chain guide and (ii) a first connecting arm, to define an extreme value of the internal angle of the articulated parallelogram at the vertex corresponding to the articulation axis shared by them. The limiter assembly has a first member on the first component and a second member on the first connecting arm, which is configured to abut the first member when the first component and the first connecting arm are rotated in the angular direction of approach of the first member to the second member. The second member extends along at least an intermediate section in the transverse direction of the first connecting arm.

A bicycle rear derailleur includes a limiter assembly arranged between (i) a first component selected between the support body and the chain guide and (ii) a first connecting arm, to define an extreme value of the internal angle of the articulated parallelogram at the vertex corresponding to the articulation axis shared by them. The limiter assembly has a first member on the first component and a second member on the first connecting arm, which is configured to abut the first member when the first component and the first connecting arm are rotated in the angular direction of approach of the first member to the second member. The second member extends along at least an intermediate section in the transverse direction of the first connecting arm.

A derailleur comprises a base member, a movable member, a linkage structure, a pulley assembly, and a rotational force control structure configured to control rotational force of the pulley assembly relative to the movable member. The pulley assembly is pivotally movable relative to the movable member about a pivot axis in first and second directions. The pulley assembly is configured to move in the first direction upon moving from a second pivotal position toward a first pivotal position. The rotational force control structure includes a cam member having a first cam surface, an abutment member configured to abut the first cam surface, and a biasing member configured to bias the abutment member. The abutment member is configured to abut the first cam surface by the biasing member to apply first additional force to the pulley assembly in the first direction while the pulley assembly is in the first pivotal position.

A derailleur comprises a base member, a movable member, a linkage structure, a pulley assembly, and a rotational force control structure configured to control rotational force of the pulley assembly relative to the movable member. The pulley assembly is pivotally movable relative to the movable member about a pivot axis in first and second directions. The pulley assembly is configured to move in the first direction upon moving from a second pivotal position toward a first pivotal position. The rotational force control structure includes a cam member having a first cam surface, an abutment member configured to abut the first cam surface, and a biasing member configured to bias the abutment member. The abutment member is configured to abut the first cam surface by the biasing member to apply first additional force to the pulley assembly in the first direction while the pulley assembly is in the first pivotal position.

A bicycle drive includes a multi-sprocket arrangement for rotatable mounting on a rear-wheel axle an engagement with a bicycle chain having inner link plate pairs and chain outer link plate pairs. The multi-sprocket arrangement includes a sprocket having, between an axial inner side and an oppositely situated axial outer side, a flat sprocket body and a plurality of teeth formed on a circumference of the sprocket. The plurality of teeth include at least one tooth of a first tooth group, the axial width of which is dimensioned to be greater than a chain inner link plate spacing and smaller than a chain outer link plate spacing, and a second tooth group, the axial width of which are dimensioned to be smaller than the chain inner link plate spacing.

A bicycle electric/electronic derailleur has a plurality of mutually movable components: a support body configured to be attached to a bicycle frame, a chain guide, and a pair of connecting arms, for connection between the support body and the chain guide at respective geometric articulation axes. A geared motor controls the motion of the plurality of mutually movable components. At least one first component has a case with a chamber containing the geared motor and/or one or more electric/electronic devices. The chamber crosses at least one articulation axis. The case comprises a blind hole that is coaxial with the one axis and open outwards of the case. A second component has a pivot pivotable in the blind hole.

A bicycle electric/electronic derailleur has a plurality of mutually movable components: a support body configured to be attached to a bicycle frame, a chain guide, and a pair of connecting arms, for connection between the support body and the chain guide at respective geometric articulation axes. A geared motor controls the motion of the plurality of mutually movable components. At least one first component has a case with a chamber containing the geared motor and/or one or more electric/electronic devices. The chamber crosses at least one articulation axis. The case comprises a blind hole that is coaxial with the one axis and open outwards of the case. A second component has a pivot pivotable in the blind hole.

Systems and methods are provided for actively controlling a derailleur. A derailleur system includes a cassette including a number of sprockets, a drive unit that drives the cassette, and a chain linking the drive unit with the cassette. A derailleur is configured to guide the chain around the cassette, the derailleur including a swing arm rotatable at a pivot assembly to maintain tension on the chain. A lock selectively locks the swing arm from rotating.