| 摘要 |
A two-way propelling type transmission mechanism for bicycle is disclosed having a control line operable to pull a bearing ring and a directional gear away from the series of clutch teeth of a first gear into engagement with the series of clutch teeth of a second gear so that pedaling the pedals to rotate cranks either forwardly or backwardly can drive the first gear to rotate a gear cluster in moving the bicycle forwards. |
