Patent ID: 7387146

Claim:
A heavy duty tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a carcass ply of cords extending between the bead portions, the carcass ply comprising a main portion extending between the bead portions through the tread portion and sidewall portions and a pair of edge portions which wind around the bead cores from the axially inside to the axially outside of the tire, wherein the wound edge portion comprises a turnback part extending from a position on the axially outside of the bead core, radially outwardly and away from a radial outer surface of the bead core, and axially inwardly towards the main portion, terminating before the main portion of the carcass, and an auxiliary cord layer disposed on the radially outside of the turnback part, whereby an end of the turnback part is positioned at a distance of from 2.0 to 8.0 mm from the radially outer surface of the bead core and wherein the turnback part is, in a tire meridian section, curved toward the radially outer surface while extending from said position on the axially outside of the bead core towards the carcass ply main portion, a space defined by the turnback, part, the bead core, and the carcass ply main portion having a generally triangular cross sectional configuration, said space being filled with a bead apex made of a low-modulus rubber having a complex elastic modulus of not more than 15 MPa, and an anchor rubber having a complex elastic modulus of not less than 20 MPa disposed in a space having a crescent sectional configuration and formed between the bead core and a base part of the carcass ply wound portion disposed under the bead core.