Abstract: The propulsion wheels of a manually propelled wheelchair are equipped with one-way engaging and one-way freewheeling clutch devices which cooperate with races fixed to the wheelchair frame, whereby unwanted backward movement of the wheelchair is prevented and forward movement at all times is enabled. An override mechanism including a spider attached to each hand propulsion ring disables the one-way engaging clutch devices when the wheelchair occupant intentionally moves the propulsion wheels in a backward mode. No controls separate from the manual propulsion wheels are present, assuring the chair occupant constant control of the chair through the hand propulsion rings at all times.