Crank set shown in the picture is equipped in chain wheels (1) used for bicycle chain which are fixed with bolts through holes (2) to BMX freewheel (3), ring (5) and crown supporting wheel (6). BMX freewheel (3) is mounted to the crank axis (9) with sleeve (4) and separates crank axis (9) from the chain wheels (1) – it works like one directional clutch. On the opposite side of crown supporting wheel (6) is mounted BMX freewheel for engine drive (7). Between crank axis (9) and crown supporting wheel (6) are put cartridge bearings (8) for better stabilization of freewheels (3) and (7). Crank (10) is fixed to the crank axis with the screw usual way. Cartridge bearings work between crank axis (9) and bottom bracket.

This solution is patented. Patent nr 199799.