a free wheeling tire having the ability to resist increased rotational speed under load is comprised of a hub portion , rim portion , and a multiplicity of flexure members defining voids extending continuously from one side of the tire to another . deleterious heat generated during operation is successfully dissipated through the increased surface area provided by the voids and by the nature of geometrical element configuration . the tires are placed in a gravity roller conveyor in arrays where each array may have different speed control characteristics permitting variations in speeds of objects as they move from one array to another .