In a pneumatic, tired wheel having a tubeless tire mounted on the rim of the wheel, the improvement comprising a toroidal support device to enable the tired wheel to travel in a flat state. The support device comprises an inflatable, toroidal, inner tube located on the rim for elastically clamping the tire beads against the rim flanges, said tube radially extending from the well of the rim to or slightly beyond the radially outer edges of the rim flanges, and a toroidal support element whose radially internal, circumferential wall section is impervious to puncture and lies adjacent the radially external, circumferential area of the inner tube, and wherein the outer surface area of the support element is spaced from the inner surface area of the tire when the tire is in its inflated state so that under normal travel conditions the support element does not contact the inner surface area of the tire. The foregoing abstract is neither intended to define the invention disclosed in the specification, nor is it intended to limit the scope of the invention in any way.