Abstract: A runflat tire system which comprises a wheel rim, a pneumatic tire and a support ring is disclosed. The support ring comprises a radially inner annular portion, a radially outer annular portion, and a supporting wall extending from the inner annular portion to the outer annular portion, wherein the supporting wall comprises a main wall extending continuously in the circumferential direction in a trapezoidal waveform, and axial walls extending axially outwardly from the main wall.

Abstract: A support ring for a runflat tire system which comprises an annular body made of an elastic material having a radially inner circumferential surface which fits to a mounting portion of a wheel rim when mounted thereon, and a radially outer circumferential surface which comes into contact with the inside of the tread portion of a pneumatic tire mounted on the wheel rim when the tire is deflated and loaded, wherein the outer circumferential surface is wider in the axial width than the inner circumferential surface, and in a cross section including the central axis of the support ring, the outline of the annular body is substantially a trapezoidal shape of which two parallel long and short sides are the outer and inner circumferential surfaces, respectively, and the remaining two sides are inclined at acute angles with respect to the long side.