Abstract: A mechanism for a rider propelled vehicle having a frame and a ground engaging wheel mounted on it comprising two lever arms on opposite sides of frame, extending backwardly, with foot pedals on their extremities and mounted each on a cylindrical oscillating shaft on opposite sides of a drive wheel gear. When these lever arms are depressed by the rider they are spring biased upwards and set in motion the mechanism that via shafts and gears winds up a spiral spring mounted into a drum incorporated in the rear wheel of the vehicle. The spring unwinds on its outer end causing the drum to rotate forward and the drum to rotate the wheel journaled on it.