Abstract: A tracked mobility device includes: a) a frame supporting a seat; b) a pair of track drives connected to the frame, with each track drive including a powered center drive wheel, a front roller, a rear roller, and a flexible track, with the center drive wheel having a diameter that is at least 50% greater than the diameter of either the front roller or the rear roller, and c) a rear wheel assembly connected to the frame, with the rear wheel assembly having three wheels sharing a common axle, with the diameter of the center rear wheel being at least 10% larger than the diameter of the two outer rear wheels; d) a source of power to power said center drive wheels; and e) a controller effective for controlling the speed and direction of rotation of each of the track drives.