| 摘要 |
A tyre having a ground contacting tread, the tread having a directional tread pattern comprises at least two substantially circumferentially extending grooves (ILG,OLG) disposed one each side of the tread circumferential centreline (C) and a plurality of circumferentially spaced apart and substantially axially extending shoulder grooves (OAG) extending axially outwardly from each circumferential groove to the tread edge (TE) to define a row of tread blocks (OB) in each axially outer tread shoulder part, the axially extending grooves (OAG) having two opposing inclined sidewalls which provide ramp support to the adjacent tread block edge, characterised in that each of the axially extending shoulder grooves (OAG) has a groove depth which reduces from the axially inward part to towards the axially outer part, and each groove (OAG) comprises two groove main portions (OAG2,OAG1) connected end to end, each groove main portion having a varying asymmetric cross-section along its length, each groove main portion having a first groove sidewall (OFT) having a constant first angle of inclination and an opposing second groove sidewall (OTR) having a varying second inclination angle, the constant first angle being greater than the maximum value of the second inclination angle, the first groove sidewall (OFT) of each groove main portion being disposed on the same side of the axial groove. <IMAGE> |
