Abstract: A device for assembling a bicycle equipped with a pedal crank system to improve the mechanics of the kinetic energy put in by the rider by simplifying the movement of the rider's feet into a reciprocating up and down movement. It consists of right and left cranksets (1D, 1G) pivoting about the axis (Ex) of the shafts (2), a chainset which includes a rack (3) that propels the ring gear (4) and the set of ring gears and chains (5, 6) by transforming the play forces through a rear changer (7) and moves forward the rear wheel via its hub receiving the propelling force of the play of the hubs of the cassettes (8) integrated in the hub of the wheel (9), or external with a system of one-way freewheel (8), fixed on the rear fork (12) by the rotating pin (Ax) also maintaining the wheel fastener (25).

Abstract: The invention concerns a device for assembling a bicycle equipped with a pedal crank system to improve the mechanics of the kinetic energy put in by the rider by simplifying the movement of the rider's feet into a reciprocating up and down movement It consists of the following parts: the right and left crankset (1D, 1G) pivoting about the axis (Ex) of the shafts (2), the chainset which includes the rack (3) and propels the ring gear (4) and the set of ring gears and the chain (5, 6) by transforming the play forces through a rear changer (7) and move forward the rear wheel vis its hub receiving the propelling force of the play of the hubs of the cassettes (8) integrated in the hub of the wheel (9), or external with a system of one-way freewheel (8), fixed on the rear fork (12) by the rotating pin (Ax) also maintaining the wheel fastener (25).