| 摘要 |
A radial tyre comprising a tread portion (5), a pair of bead portions (3) each with a bead core (2) therein, a pair of sidewall portions (4) extending therebetween, a radial carcass (6) extended between the bead portions (3) and turned up around the bead cores (2), and a belt (7) disposed radially outside the carcass (6), said tread portion (5) provided with a block pattern (P) consisting of blocks (B1,B2) defined by at least one circumferential groove (M) and a plurality of axial grooves (N), characterised by the said block pattern (P) having a land ratio of not less than 0.67, said land ratio being defined as the total (Sb) of the top surface areas of all said blocks (B1,B2) divided by the total area (St) of the tread face, and for blocks BT which exist wholly or partially in the ground contacting part of the tread (5), the total SIGMA (sigma)IX of the second moment of areas IX of all said blocks BT being larger about the axial areas x than the total SIGMA (sigma)IY of the second moment of areas IY about a circumferential axis y of all said blocks BT, wherein each said second moment of area IX is that of the top surface of each block BT about a circumferential line (X) passing through the centre point (O) on the top, ground contacting surface, and the second moment of area IY is that of the top, ground contacting surface about an axial line (Y) passing the centre point (O). <IMAGE> |
