Nonreinforced tire

In a nonreinforced inflated tire mounted on a wheel rim, said tire consisting of at least one elastic material and having a tread-forming crown extended on both sides by a sidewall terminating in a bead, each sidewall as seen in radial section having an outer wall and an inner wall and a median line which is the line of the centers of circles which are tangent both to said outer wall and to said inner wall, each circle being entirely included within said radial section, the improvement which comprises each sidewall has at least one sequence of zones A, B, C, D without interruption of continuity, formed of a zone C of substantially constant thickness, and, on opposite sides of the zone C, a zone B in which the thickness of the tire increases as it moves away from the zone C, the thickness of this zone B at its end opposite zone C being at least two times the thickness of the zone C, and a terminal zone D in which the thickness of the tire increases as it moves away from the zone C, the ratio of the increase in thickness of the zone D per unit of length of the median line being less than the ratio of increase in thickness of the zone B per unit of length of the median line, and finally a terminal zone A following the zone B and whose maximum thickness is equal to at least the greatest thickness of the zone B, said median line having a reversal of curvature which is located in a zone C in the vicinity of the junction between zones B and C.