Patent ID: 7270164

Claim:
A pneumatic tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, a carcass extending between the bead portions, and a belt disposed radially outside the carcass in the tread portion and comprising a breaker and a band, wherein (1) the breaker comprises two cross plies of steel cords laid at an angle of from 10 to 35 degrees with respect to the tire equator, (2) the band is disposed radially outside of the breaker to cover at least the axial edges of the breaker, the band comprising a PEN cord ply of at least one polyethylene-2,6-naphthalate fiber cord which is wound spirally around the breaker at an angle of not more than 5 degrees with respect to the tire equator, wherein the polyethylene-2,6-naphthalate fiber cord has a total denier number of from 2500 to 3600, a twist number of from 30 to 40 turns/10 cm, an initial stage modulus at 25 deg. C. which is in a range of from 50 to 65 gf/d, and a variation of the initial stage modulus in a temperature range between 25 deg. C. to 70 deg. C. which is not more than 20% in absolute value, and (3) the carcass comprises a PEN cord ply of polyethylene-2,6-naphthalate fiber cords each having a loss tangent of from 0.06 to 0.09, a complex elastic modulus of from 2800 to 4000 N/cord, a variation of the loss tangent in the temperature range between 25 deg. c. and 70 deg. c. which is not more than 20% in absolute value, a variation of the complex elastic modulus in the temperature range between 25 deg. c. and 70 deg. c. which is not more than 20% in absolute value, and the polyethylene-2,6-naphthalate fiber cords are arranged radially at an angle of from 70 to 90 degrees with respect to the tire equator, and each of the cords has a total denier number of from 2500 to 3600, a twist number of from 30 to 40 turns/IO em, an initial stage modulus of 25 deg. c. which is in a range of from 50 to 65 gf/d, and a variation of the initial stage modulus in a temperature range between 25 deg. c. to 70 deg. c. which is not more than 20% in absolute value.