Abstract: A wheel assembly includes a wheel rim and a tire mounted on the wheel rim. The tire includes an outer side wall, an inner side wall, an inner surface connecting the outer side wall and the inner side, and an outer contact surface connecting the outer side wall and the inner side. The tire has a rim opening extending through a central longitudinal axis of the tire. Flexible foam is provided inside of a volume formed by the outer side wall, the inner side wall, the inner surface, and the outer contact surface.