The drive comprises an endless toothed drive belt passing around belt pulleys but not enclosing the lower rear wheel forks. The ;ower rear forks are connected to the saddle tube above the bottom bracket bearings clear of the pedal crank radius. The upper and lower rear wheel forks form a non-separable joint at the rear wheel axle. The belt is flat toothed and made of aramid fibre. Increasing the wheelbase by adjusting the positions of the rear wheel axle and eccentric crankshaft pretensions the drive belt.
