Abstract: A pneumatic radial tire including one or more belt layers, wherein cords are used as cords for reinforcing at least one belt layer. These cords are formed by impregnating and attaching a resin having a modulus in tension of not more than 150 kg/mm.sup.2 to bundles of cord-like fibers composed of a number of filaments having a tensile strength of not less than 15 g/d and a fineness of 1-15 deniers, an impregnated and attached amount of the filaments being in a range of 30% to 70 wt % relative to a weight of the filaments, and each of the cords has an elliptical or rectangular cross-section shape having an aspect ratio of a major axis (b)/a minor axis (a) being 1.5 to 5. Each of the bundles of the fibers are not twisted.

Abstract: A pneumatic radial tire comprises a belt comprised of plural belt layers, in which at least one belt layer is formed by arranging particular twisted cords, which are obtained by twisting particular filament-resin composite bodies, at a particular end count. In this tire, the weight is light, the rolling resistance and steering stability as well as the resistances to bending of belt cord in the rapid turning and breaking of belt cord in the running on bad road are considerably excellent.

Abstract: A pneumatic radial tire is disclosed. This tire is reinforced with steel cords, each of which has such a flat or elliptic section that two or three strands, each strand being produced by twisting plural filaments, are arranged in parallel with each other so as to make the twisting directions of the adjoining strands opposite to each other to form a core and plural filaments are twisted around the core and wrapped with a spiral filament.