Abstract: A transmission mechanism is used in a bicycle having a frame. The transmission mechanism includes a quick assembly device including a central shaft, threaded collars, and a clip bracket, which is adapted to mount to a lower frame portion of the bicycle frame and a multi-mode mechanism, which is supported and fixed by the quick assembly device to provide the bicycle with multiple modes of pedaling.

Abstract: An improved multifunctional pedaling motion bicycle, particularly to a transmission mechanism of bicycle includes a clutch member that is manually controlled to move between and selectively engage primary and secondary control blocks to perform different modes of operation of the bicycle, including regular pedaling, independent pedaling of cranks, same-direction upward/downward movements of the cranks. The transmission mechanism has a simple and light-weighted structure and thus low cost and low failure risk with extended service life. Further, a variety of different operation modes can be performed without dedicated rear hub.