Abstract: A chain drive for use on a bicycle having a conventional frame and wheels. The chain drive comprises a wheel hub mounted for rotation on the frame. The opposite end portions of the hub are disposed on opposite sides of the frame, respectively. Two sprocket devices are mounted on the opposite end portions, respectively, of the hub for imparting rotation thereto. A pedal operated crank is also mounted for rotation on the frame, and includes two coaxial sprockets secured to the opposite ends of the crankshaft. The crank sprockets are axially spaced, parallel and disposed on the opposite sides, respectively, of the frame. The two sprocket devices and the two crank sprockets are radially aligned, respectively, one sprocket device being associated with one crank sprocket. Two chains are mounted on the aligned sprocket devices and crank sprockets, respectively, for driving the wheel hub by means of the crank.