Abstract: A pneumatic radial tire including at least one ply of carcass layer comprising a number of cords disposed at right angle with respect to a circumferential direction of the tire and anchored at a pair of beads, said cords of the carcass layer being treated with adhesive treating agents, i.e. an epoxy treating agent and a RFL treating agent, at the stage of both yarns and cords, said cords being formed by twisting at least two treated strands which are formed by twisting yarns treated with both the epoxy treating agent and the RFL treating agent and said cords being further treated with at least the RFL treating agent.

Abstract: Highly durable radial tires, particularly highly durable radial tires hav a plurality of carcass plies of organic fiber cords and used for light trucks as well as heavy duty vehicles wherein at least one of the plies is composed of polyamide cords having superior heat resistance in a rubber and the remaining plies or ply are composed of polyester cords.

Abstract: Reinforcing layers for bias tires comprising a laminated structure of a steel cord ply and composite cord plies made of aramid yarns and nylon yarns, said composite cord plies being disposed radially outwardly of the steel cord ply maintaining a full space between steel cords and composite cords and a nominal total denier of said composite cords being in the range of 4,000-10,000.

Abstract: A radial tire improved in steering stability, durability and appearance comprising a nylon cord of high modulus and excellent dimensional stability obtained by impregnating a nylon cord substantially composed of polytetramethyleneadipamide with an adhesive and heat setting the nylon cord under a stretch state.