| 摘要 |
A pneumatic tyre (1) comprising a tread part (2) having two circumferential grooves (5,5) continuously extending in the circumferential direction in either side of the tyre's equator so as to divide the tread part (2) into a pair of shoulder parts (4,4), which are located outside outer bottom edges (6b) of the circumferential grooves in the axial direction of tyre, and a central part (9), which is located between inner bottom edges (6a) of the circumferential grooves in the axial direction of tyre; characterised in that the central part (9) has a surface comprising successive convex curves composed of a pair of inner groove walls (9A) extending inside, in the axial direction of tyre, along a curve convex outwardly in the radial direction from the inner bottom edges (6a) of the circumferential grooves (5) and a central ground-contacting surface (9B) smoothly connected between the pair of the inner groove walls (9A), the central ground-contacting surface (9B) is substantially in contact with a virtual tread line (7) between outer surfaces (10) of the shoulder parts, the surface of the central part (9) is asymmetrical about the tyre equatorial plane CL, and when the tyre (1) is mounted on a regular rim R, inflated with regular internal pressure and applied with normal load, the circumferential grooves (5) have a groove width GW being not less than 35 mm and not more than 0.35 times a ground-contacting width TW of the tread. <IMAGE> |
