| 摘要 |
A bicycle includes a front wheel attached to a front fork, a rear wheel attached to a rear fork, and a pair of cranks and a driving sprocket attached to a wheel hub of the bicycle frame, a foot pedal drive and propulsion device includes a shaft attached to the bicycle frame and located behind the rear wheel and disposed parallel to the rear wheel axle, a pair of levers each include a middle portion pivotally attached to the cranks and a rear portion slidably coupled to the shaft to form a retractable and telescopic structure, and a pair of foot pedals are adjustably attached to the front portions of the levers at selected positions for applying an increased driving torque to the cranks. |
