Patent ID: 7828028
Filing Date: 2010-11-09
Classification: B60C,Y10T

Abstract:
1. A pneumatic tire for a two-wheeled vehicle, comprising: bead cores embedded in a right and left pair of bead parts; a semi-radial bias carcass layer which extends from one bead part to the other bead part in the shape of a toroid, end portions of which are rolled up around the bead cores to be latched at the bead cores; a radial reinforcement band layer which is disposed only at an inner side of tread ends in a tire width direction, and is disposed at a tire radius direction outer side of a crown part of the semi-radial bias carcass layer, comprising at least one ply at which a plurality of reinforcement cords extending in a radial direction are arranged; a belt layer which is disposed at an outer side of the radial reinforcement band layer in the tire radius direction, comprising at least one belt ply at which a plurality of reinforcement cords are arranged; and a tread layer which is disposed at an outer side of the belt layer in the tire radius direction, wherein, in the semi-radial bias carcass layer, at least two carcass plies in which a plurality of reinforcement cords extending in a direction of 50 deg to 80 deg with respect to a tire equatorial plane are arranged are provided such that the reinforcement cords of the respective carcass plies are crossed with each other, and assuming that the absolute value of the total sum of rigidity components in a circumferential direction of the belt layer is |ΣFb| and the absolute value of the total sum of rigidity components in a width direction of a case made up of the semi-radial bias carcass layer and the radial reinforcement band layer is |ΣFc|, |ΣFb|/|ΣFc|=1.3 to 3.0 in a case in which the reinforcement cord constituting the belt layer is a textile cord, and |ΣFb|/|ΣFc|=0.03 to 0.1 in a case in which the reinforcement cord constituting the belt layer is a steel cord, provided that where Mbi: the initial modulus of elasticity at 0.5% elongation for the reinforcement cord constituting the respective belt layers (the unit is cN/dtex for the textile cord, and is kN/mm Nbi: end count (cords/cm) for the reinforcement cord constituting the respective belt layers αbi: inclination angle (deg) with respect to the circumferential direction for the reinforcement cord constituting the respective belt layers and where Mpi: the initial modulus of elasticity (cN/dtex) at 0.5% elongation for the reinforcement cord constituting the carcass ply Msi: the initial modulus of elasticity (cN/dtex) at 0.5% elongation for the reinforcement cord constituting the radial reinforcement band layer Npi: end count (cords/cm) for the reinforcement cord constituting the carcass ply Nsi: end count (cords/cm) for the reinforcement cord constituting the radial reinforcement band layer αpi: inclination angle (deg) with respect to the circumferential direction for the reinforcement cord constituting the carcass ply αsi: inclination angle (deg) with respect to the circumferential direction for the reinforcement cord constituting the radial reinforcement band layer.