A tracked mobility device includes a pair of track drives having a rear weight-bearing wheel assembly, a center weight-bearing wheel assembly, a forward weight-bearing wheel assembly, and a front roller assembly. The rear weight-bearing wheels, the center weight-bearing wheels, and the forward weight-bearing wheels are fixed to the frame at a height effective to cause the main weight-bearing surface to always have a “V”-shaped lower surface when viewed from the side. The center weight-bearing wheels, the forward weight-bearing wheels, and the front rollers are fixed to the frame at a height effective to cause that portion of each track drive always to have a “V”-shaped lower surface when viewed from the side. At least one powered drive wheel is provided, and at least one of the rollers is a tensioning roller.