Patent ID: 6736177
Filing Date: 2004-05-18
Classification: B60C,Y10T

Abstract:
A pneumatic tire comprisinga pair of bead portions each with a bead core therein, a carcass comprising one ply of cords extending between the bead portions through a tread portion and sidewall portions and turned back in each said bead portion from the axially inside to the axially outside of the tire and wound around the bead core in each said bead portion so as to form a pair of wound portions and a main portion therebetween, each said wound portion having a radially outer part extending axially inwards along the radially outer face of the bead core to have a length not less than 0.5 times the width of said radially outer face when measured along the radially outer face, each said bead portion provided between said radially outer part and the radially outer face of the bead core with an organic fiber cord layer, a distance between the carcass cords in said radially outer part and the radially outer face of the bead core being in a range of to not more than 1.0 times the section height of the bead core when measured in a normal direction to the radially outer face of the bead core, wherein in each said bead portion, a reinforcing layer of cords is disposed radially outside the radially outer part so as to secure the radially outer part between the reinforcing layer and the bead core, a bead apex rubber is disposed radially outside the reinforcing layer, and a chafer rubber is disposed axially outside the bead apex rubber along an axially outer surface and bottom surface of the bead portion, and the bead apex rubber has a 100% modulus in a range of from 6.3 to 8.6 MPa, the chafer rubber has a 100% modulus in a range of from 5.4 to 8.2 MPa, and the 100% modulus f the chafer rubber is less than the 100% modulus of the bead apex.