Abstract: In bicycle having a frame on which is mounted a front wheel and a rear wheel having a primary axis of rotation, said rear wheel including a rotary drive connected with a multi-speed gear; a wheel frame constructed to support a tire rim connected to said rotary drive, a plurality of spokes for supporting said tire rim on said hub said, and a plurality of spokes, the improvement comprising; a weighting device releasable attached to said rear wheel for adding weight concentrated at said rear wheel's periphery consisting of a matched pair of rings, releasable clip fastener for mounting the weighting device adjacent the periphery of the rear wheel by fastening said rings on the spokes; wherein rotational momentum is increased and concentrated in the rear wheel as said rear wheel is driven by said rotary drive operated by said multi-speed gear by the rider wherein said weighting device acts as a flywheel member adding to said momentum of said cycle.