Abstract: A wheelchair drive system is described that operatively interposes a plural-speed hub subsystem between conventional rotatable hand wheels and their corresponding drive wheels, thereby providing wheelchair propulsion by rotary motion of the hand wheels and selective engagement of the drive wheels dependent upon a manually operated gear-shifting mechanism. Preferably, the hub subsystem includes symmetric left- and right-handed hubs each including a hub body fixedly connected with an easily accessible hand wheel, with the hub body rotating about a spindle fixedly mounted on the wheelchair and selectively gear-connectable to the drive wheel, the spindle being selectively connected to the drive wheel by the operation of a manually shiftable, plural-speed gear train.