| 摘要 |
PROBLEM TO BE SOLVED: To take a balance between the high-speed performance and comfortableness of riding by spirally winding a band-like ply provided with a compound cord, which is obtained by twisting aramid strand and nylon strand and of which dynamic elastic modulus is restricted in a specified range, in nearly parallel with a tire equator so as to form a band layer. SOLUTION: As a cord 9 of a band layer, a compound cord obtained by twisting an aramid strand 9A, which is formed by twisting an aramid filament, and a nylon strand 9B, which is formed by twisting a nylon filament, is used. This compound cord has a viscoelasticity characteristic that dynamic elastic modulus E* thereof per each one cord at 80 deg.C is 340 kgf or more and that dynamic elastic modulus E* per each one cord at 120 deg.C is 290 kgf or less. Since the dynamic elastic modulus E* in the high temperature condition is set low, this cord is soft in a practical traveling speed area corresponding to a low frequency, and comfortableness of riding is obtained. |
