Motorradluftreifen

摘要

A pneumatic motorcycle tyre comprising a tread portion (2) with axial edges (E1,E2), said tread portion (2) being curved so that the maximum cross sectional width of the tyre lies between the tread edges (E1,E2), a pair of axially spaced bead portions (4), a pair of sidewall portions (3) extending between the tread edges and the bead portions (4), a pair of bead cores (5) one disposed in each bead portion (4), a carcass (6) having a main portion (6a) extending between the bead portions (4) and a pair of turned up portions (6b) each turned up around each said bead core (5), a belt (7) disposed radially outside the carcass (6) and inside the tread portion (2), said belt (7) being formed by spirally winding a ribbon-shaped strip (10) of rubber in which a single cord or a plurality of parallel cords are embedded along the longitudinal direction thereof, at a small angle to the tyre equator (C), characterised by a pair of axially spaced reinforcing cord layers (9) disposed radially inside of the belt (7) and outside of the carcass (6), each reinforcing cord layer (9) extending from a point (P1) in the tread portion (2) on each side of the tyre equator (C) towards the sidewall portion (3) over the belt edge, said point (P1) being spaced apart from the tyre equator (C) such that, when a straight line is drawn normal to the tread surface through the point (P1), the distance measured along the tread surface (2) from the tyre equator (C) to the normal line is in the range of from 0.2 to 0.3 times the tread surface width WT measured along the tread surface from one tread edge (E1) to the other tread edge (E2), each reinforcing cord layer (9) comprises a ply of parallel organic fibre cords (14) inclined at an angle of 20 to 70 degrees to the tyre equator, said ply being rubberised with a topping rubber having a 100% modulus of 25 to 55kgf/cm<2>.