| 摘要 |
<p>PROBLEM TO BE SOLVED: To greatly reduce the weight and improve the productivity while keeping control stability and comfortableness balanced and maintaining actual performance. SOLUTION: A topping rubber for a carcass ply 6A has an inside topping portion, defining a tire cavity face S, only formed of butyl based rubber. The height (ha) of a bead apex is 10-20 mm and the turnaround height (hb) of a ply turnaround portion 6b is 0.3-0.7 time the sectional height H of a tire. The ply turnaround portion 6b has a proximity area 15 formed in proximity to a ply mainbody portion 6a outward of the outward end 8t of an apex rubber 8. A ply turnaround portion 15 is curved at a radius of curvature R of 5-15 mm in proximity to the outward end 8t. A rubber thickness Tb between the ply mainbody portion 6a and the ply turnaround portion 6b in the proximity area 15 is 0.3-0.8 mm.</p> |
