#$%^&*AU2018222900A120200312.pdf#####ABSTRACT The present invention relates to a wheel per se, and an attachment that may be applied to a wheel to improve support as required. The wheel and wheel attachment may be useful in improving support in a range of wheeled contrivances such as wheelchairs, bicycles, infant pushers and strollers, road vehicles, off-road vehicles, heavy vehicles, trolleys, and trailers. The invention extends also to other forms of rolling means such as caterpillar-type rolling means. The invention may be embodied in the form of a rolling means comprising: a first support surface formed as a loop configured to roll on a substrate such that a region of the first support surface alternately contacts and separates from the substrate, a first extension running about the loop and disposed about the first support surface, wherein where the rolling means is disposed on the substrate and a load is applied thereto: in a first region of the loop where the first support surface is separate from the substrate the first extension extends beyond the first support surface, and in a second region of the loop where the first support surface contacts the substrate the first extension is deformed so as to form a second support surface which contacts the substrate.2/10 10 35 25a 25b 15 30a 30b FIG. 2A 10 25a ~ 3525 40 30a 50a 15 50b 30b FIG. 2B