Pneumatic semi-radial tires for motorcycles

摘要

A pneumatic semi-radial tire for motorcycle is disclosed, which comprises a tread, a pair of sidewalls, a carcass composed of at least one rubberized ply containing organic fiber cords inclined at an angle of 50°-85° with respect to the equatorial plane of the tire, and a belt disposed between said tread and said carcass at a width corresponding to a tread width and composed of at least two rubberized plies each containing cords with a modulus of elasticity of at least 600 kg/mm.sup.2 arranged at an inclination angle of 15°-30° with respect to the equatorial plane of the tire. In the tire, each end of at least one rubberized ply constituting the carcass is wrapped around a bead ring embedded in each radially inner end portion of the sidewalls toward a direction of the tread to form a turnup portion in which cords of the carcass are crossed with cords of the turnup portion in the sidewall; a stiffener inclusive of a tapered rubber filler extending from an upper part of the bead ring toward the tread direction and having a Shore A hardness of at least 60° is disposed between the carcass and the turnup portion thereof or outside the turnup portion; and at least one of radial heights extending from the bead base to ends in the tread direction of the stiffener and turnup portion corresponds to at least 60% of the radial height of the sidewall.