| 摘要 |
PROBLEM TO BE SOLVED: To improve abrasion resistance and steering stability while maintaining run-flat durability and riding comfortableness.SOLUTION: A run-flat tire includes side reinforcement rubber parts 8 in which the ratio of a tensile stress (M50H) at the time of 50% elongation at 100°C to a tensile stress (M50N) at the time of 50% elongation at 23°C is 1.0 to 1.3. Belts 13 are formed of a steel cord 20 having an n+1 structure by winding a wrapping filament 23 around a main filament bundle 22 in which main filaments are arranged in a row, and the ratio of a cord short diameter (Da) after pressing to a cord short diameter (Db) before pressing is 0.80 or less. In a tread rubber part 9, the rubber hardness (Hc) of a cap rubber layer 10 at 60°C is greater than the rubber hardness (Hb) of a base rubber layer, and Hc-Hb is 5 to 15. The volume ratio of the cap rubber layer is more than 50% in the shoulder area, and the volume ratio in the shoulder area is higher than the volume ratio in the center area. |
