AUXILIARY DEVICE FOR SPEED CHANGE GEAR OF BICYCLE

摘要

PROBLEM TO BE SOLVED: To provide an assistant device capable of reducing the operation of a speed change gear of a bicycle, possible to be used with two or more sprockets, and capable of restricting the number of movable parts always moving to the minimum. SOLUTION: This assistant device using the force from a rotor to assist the operation of the speed change gear of a bicycle is provided with an installing member, an input transmitting member to be moved to a first input position, a second input position and a third input position, an output transmitting member to be moved to a first output position, a second output position and a third output position respectively corresponding to each input position of the input transmitting member, a rotor engaging member to be moved between a rotor engagement position and a rotor non- engagement position, a movement transmitting mechanism for transmitting the movement from the rotor engaging member to the output transmitting member, and a switching mechanism for moving the rotor engaging member to the rotor engagement position when the input transmitting member and the output transmitting member are not positioned corresponding to each other and for moving the rotor engaging member to the rotor non-engagement position when the input transmitting member and the output transmitting member are positioned corresponding to each other.