| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire which uses a cord including aramid fibers as a reinforcing cord of a carcass ply, and is made compatible in both the weight reduction of the tire and high-speed durability.SOLUTION: A pneumatic tire 10 has a carcass which is composed of at least one piece of a carcass ply 4 as a skeleton. A reinforcing cord of the carcass ply 4 contains alarmed fibers, an over-twinning coefficient T expressed by the following formula T=N×√{(0.125×D/2)/&rgr;}×10(in the formula, N is a twinning number of the cord (10 cm per one round), D is the total fineness of the cord, and &rgr; is the density of the cord) is not larger than 0.4, the total fineness is not higher than 1,800 dtex, and the number of times of the implantation of the reinforcing cord at the carcass ply is not smaller than 55 pieces per 5 cm. |
