| 摘要 |
<p>A pneumatic tire (1) comprises a radial carcass (3) of at least one carcass ply (4) wound around each of bead cores (2) from the inside toward the outside to form a turnup portion (6), an outer ply (10) inclusive of the turnup portion containing cords each having a modulus of elasticity of not less than 2500 kg/mm<2> and a diameter d, and a rubber stiffener (20) arranged at its radially inward portion between the carcass ply and the outer ply. In a bead structure (7) of such a pneumatic tire, the stiffener (20) is divided into an inner stiffener portion (21) and an outer stiffener portion (22) around a specified boundary plane (X), and each of these stiffener portions (21,22) is comprised of rubber having a given Shore A hardness of 58 DEG to 68 DEG and of not more than 55 DEG respectively, and a volume ratio of the outer stiffener portion in the stiffener is not less than 10%. <IMAGE></p> |
