Abstract: The invention provides an assembly of a pneumatic tire and a rim. The tire has at least one carcass ply 2 and a belt layer 8. The ply 2 is composed of ply cords and has end portions. The belt layer 8 is composed of belt cords provided outside of the ply 2. Each belt cord extends in a direction intersecting the ply cord. Each of the end portions is held in the rim 12. The width of the tire is maximum in a circumferential cross section “T” with a cylindrical shape with respect to the center axis “D” of the tire. The cross section “T” extends through the rim 10. When the tire is rolled under a load and a stress is applied on the tire as an arrow “X”, a neighboring portion 2d near the end portions 2a, 2b is considerably bending-deformed as arrows “Y” to absorb the stress. The roundness of the belt layer 8 is thus preserved to reduce the rolling resistance of the tire considerably.

Abstract: In many designs, a tire (14) of a wheel (10) is inadequately restrained with respect to a tire supporting rim assembly (12) of the wheel. Movement of the tire (14) with respect to the rim assembly (12) results in a wastage of energy. In the present invention a wheel assembly (10) has a rim assembly (12) and a tire (14) mounted on the rim assembly (12). The rim assembly (12) has an annular elastic element (22) affixed thereto for increasing the coefficient of friction between said rim assembly (12) and the tire (14).