Propulsion and speed change mechanism for lever propelled bicycles having a pair of propulsion levers 4, each of which is built in one piece with a speed change arm 3 and mounted in each side of the main shaft portion 2 at the bottom of the bicycle frame 1. A rear axle 5 and a hub 6 is mounted on the rear shaft portion 2'. A one-way clutch mechanism has roller-type free wheels 11a installed at both ends of the rear axle. Chains 7", the ends of which may be connected together with a see-saw cable 7', are entrained around gears 7 and guide rollers 13. The free ends of the chains are connected by connecting bars 14 having pins to the speed change arm 3. Pivotally mounted members 15 of triangular shape and a cam bar 17 operated by a speed control knob 18 are used to change the effective length of the arm for speed control.