| 摘要 |
PROBLEM TO BE SOLVED: To provide a gear shift device of improved operation precision.SOLUTION: A gear shift device 10 with a motor for a bicycle includes a deformable articulation type motion mechanism 20 which is intended so as to be fixed to a frame T of the bicycle, a chain guide 40 which is held by the deformable articulation type motion mechanism and can take a different position to the frame T of the bicycle according to a different operation state of the motion mechanism, and a motor member 50 attached to the motion mechanism in such a manner as contains motor casings 51;151 and a master drive shaft 52 which directly protrudes from the motor casings, to deform the articulation type motion mechanism such that it takes a different operation state. The master drive shaft cannot be rotated and translation motion is possible in axial direction to the motor casing 51. |
