Patent ID: 7628095

Claim:
A bicycle shifting mechanism comprising: a wire takeup member configured and arranged to rotate about a rotational axis; a positioning mechanism selectively maintaining the takeup member in one of a plurality of predetermined shift positions, the positioning mechanism including a first movable positioning member, a second movable positioning member separately movable relative to the first positioning member, a first toothed segment that moves with the takeup member, and a second toothed segment that moves with the takeup member, the first and second movable positioning members alternately engaging and disengaging one of the first and second toothed segments, respectively, as the first and second movable positioning members are moved during performance of a single shifting operation between sequential shift positions of the predetermined shift positions, the first and second movable positioning members both engaging respective first and second toothed segments in a single shifting direction during the single shifting operation; and a wire releasing mechanism including engaging toothed segments for alternately engaging the first and second movable positioning members, the engaging toothed segments being rotatably supported to rotate around a rotational axis offset from the rotational axis of the wire takeup member.