Radial tire having a highly durable bead structure

A radial tire having a highly durable bead structure, comprising a carcass ply composed of a rubberized layer containing a plurality of cords parallel to one another and disposed in radial relationship with respect to the equatorial line of the tire and at least two inner reinforcing cord layers covering that portion of the carcass ply which is wound about a bead core from the inside toward the outside thereof and extended upwardly to form a turn up portion and each composed of a plurality of cords inclined with respect to tangential lines touching at a circle formed by the bead core, in the tire the upper end of at least one of the inner reinforcing cord layers is located at a position which is lower than the upper end of the turn up portion of the carcass ply by (1/10 to 1/2)h.sub.0 where h.sub.0 is a vertical height of the upper end of the turn up portion of the carcass ply measured from a base of the bead, a space formed between the turn up portion of the carcass ply and a reinforcing cord layer exclusive of said reinforcing cord layer has an interlayer gauge d measured on a line passing through the upper end of the turn up portion of the carcass ply and perpendicular to the carcass ply and defined by d = (1/30 to 1/5)D where D is a thickness of that portion of the bead which is measured on said line, where h.sub.0, d and D are measured after the tire has been mounted and normally inflated, and a rubber having a modulus of elasticity of 20 to 100 Kg/cm.sup.2 at 100% elongation is inserted into said space.