Abstract: A drive for a wheeled vehicle including a hub adapted to receive the driving wheel of such vehicle. The hub receives and rotatably supports an axle having a worm screw thereon and positioned within such hub. The worm in turn supports an eccentrically weighted driver of drum-like configuration so that rotational force transmitted to the axle in either direction traverses the weighted driver back and forth within the hub in a generally upright position. The driver resists rotation with the axle by reason of its eccentrically weighted configuration. Driving contact is made between the outer face of the driver and the inner face of the hub ends at opposite sides thereof so that rotation of the axle will cause driving force to be imparted to the hub in either direction dependent on which end of the hub the driver is contacting.