Mechanical chain transmission for bicycle, has pedal assembly with driving sprocket displaced laterally parallel to rotation axis of assembly by actuator with roller whose rotation axis is not merged with rotation axis of pedal assembly

摘要

The transmission has a rear derailler, a chain, a set of driven crown wheels and a pedal assembly with a driving sprocket that is displaced laterally parallel to a rotation axis (15) of the pedal assembly by using an actuator (16) having a swiveling roller (23). The sprocket takes a lateral position comprised between end positions, under action of the actuator. The roller is mounted rotating around a shaft (22). An axis of rotation of the roller is not merged with the rotation axis of the pedal assembly.