Abstract: Non-circular front chain wheel for a crank gear is comprised of a crank gear wheel allowing to a progressive increase of the cycling torque from the dead point up to the point where the extension of the leg allows to create the maximum effort, due to a progressive variation of the primitive radius of the toothing between these two points, followed by a rapid decrease to the next dead point. The principle is that the force to be provided is proportional to the muscular force that the user may provide. The non-circular front chain wheel essentially pertains to the cycle industry but may also find applications in other fields, for example physical exercisers for body building or reeducation, and in general all apparatus utilizing cycling motion and a chain or belt transmission system between the front wheel or wheels of the crank gear and one or a plurality of pinions actuating the device to be driven.