| 摘要 |
A pneumatic tyre comprising a tread portion (5), said tread portion (5) provided with a main groove (10) extending continuously in the circumferential direction of the tyre and circumferentially spaced lateral grooves (11A,11B) each extending axially from the main groove (10) to one side of the main groove, defining pitches between the intersections of said lateral grooves (11A,11B) with the main groove (10), the pitches including at least two different length pitches (P1,P2), the width (GW) of the main groove (10) at the groove top being substantially constant along its length, and characterised in that the sectional area of the main groove is changed along its length such that <MATH> is 0.5 to 1.5 times <MATH> wherein S(i) is the sectional area in one pitch having a length P(i) and S(i+1) is the sectional area in the next longer pitch having a length P(i+1). <IMAGE> |
