PURPOSE: To restrict the deformation of tires at the time of cornering to enhance the feeling of stiffness, in the tires, each of which is provided with a carcass made up of plural rubber-coated cords by forming the cords by twisting plural thermal contractile organic fibers, and specifying the twist coefficient.
CONSTITUTION: In carcass plies 16, 18 turned up around a bead core 12 from the inside of a tire toward the outside in the radial direction of the tire, rubber- coated cords which are constructed for plural thermal contractile organic fibers such as nylon, polyester to be twisted, are used as the cords, and the direction of the cords directed toward the radial direction. Further, as the cords using such carcass piles 16, 18, the cords with the twist coefficient of 0.1 to 0.5, represented by the following formula, are used: Twist coefficient = N×(0.139×D/ρ)1/2×10-3, where N = twist number per 10cm of the length of thermal contractile organic fiber, D= total denier of thermal contractile organic fiber, ρ= specific gravity of thermal contractile organic fiber.
KODAMA SUNAO
SUGANUMA TOSHIO
HOSOYA YOSHIHIRO
