Patent ID: 7526979

Claim:
A bicycle shift position control mechanism comprising: a wire take up member configured and arranged to rotate about a rotational axis; a positioning member configured and arranged to rotate with the wire take up member between at least three distinct predetermined shift positions; a first position maintaining member being selectively movable between a first engagement position and a first disengagement position in which the first position maintaining member engages the positioning member to hold the positioning member in at least one of the at least three distinct predetermined-shift positions when the first position maintaining member is in the first engagement position, and in which the first position maintaining member disengages the positioning member to release the positioning member for rotational movement when the first position maintaining member is moved from the first engagement position to the first disengagement position, with the first position maintaining member and the positioning member being in non-contacting positions with respect to each other when in the first disengagement position; and a second position maintaining member being selectively movable between a second engagement position and a second disengagement position in which the second position maintaining member engages the positioning member to hold the positioning member in at least one of the at least three distinct predetermined shift positions when the second position maintaining member is in the second engagement position, and in which the second position maintaining member disengages the positioning member to release the positioning member for rotational movement when the second position maintaining member is moved from the second engagement position to the second disengagement position, with the second position maintaining member and the positioning member being in non-contacting positions with respect to each other when in the second disengagement position, the first and second position maintaining members alternately engaging the positioning member during three sequential shifting operations corresponding to the at least three distinct predetermined shift positions to alternately maintain the positioning member in the at least three distinct predetermined shift positions such that one of the first and second position maintaining members is contacting the positioning member and the other of the first and second position maintaining members is not contacting the positioning member when the first and second position maintaining members are at rest positions.