| 摘要 |
The ride comfort and driving performance of a pneumatic tire 11 are improved while maintaining the high-speed durability and steering stability, in which an inclination angle A of steel cords 26, 27 in all belt plies 24, 25 constituting a belt layer 23 is not less than 45° with respect to an equator S of the tire, and a belt reinforcing layer 35 embedded with reinforcing cords substantially in parallel to the equator S is arranged between a belt layer 23 and a carcass layer 18, whereby an out-of-plane bending rigidity of the belt layer 23 in a circumferential direction can be lowered to make a longitudinal spring constant of the pneumatic tire 11 and uniformize the diameter of the belt reinforcing layer 35, and further a deformation amount of a tread portion 15 having a high bending rigidity can be made small. |
