TIRE TREAD WITH CIRCUMFERENTIAL TREAD GROOVE

A tire (1) is disclosed comprising a tread (10) having a tread groove (30) extending continuously in the circumferential direction, wherein the tread groove (30) as a top portion (31), a bottom portion (33) and a transition portion (32) located radially between the top portion (31) and the bottom portion (33). In one aspect, a maximum axial width of the tread groove (30) in the top portion (31) is 2 mm, wherein the tread groove (30) has axially opposed sidewalls (25, 26), and wherein the axially opposed sidewalls are tapered towards each other in the bottom portion (33) when moving radially inwards, and wherein the opposed sidewalls in the transition portion (32) are tapered away from each other when moving radially inwards, In another aspect, the tread groove (30) has over most of its circumferential length a cross-section in which a maximum axial width in the top portion (31) is at least 5% smaller than an axial width in the bottom portion (33), as measured at 5% of a total radial height of the tread groove (30) from the bottom of the tread groove (30), in which the axial width in the bottom portion (33) is at least 5% smaller than a maximum axial width of the tread groove (30) in the intermediate portion (32), and in which the maximum axial width of the tread groove (30) in the intermediate portion (32) is within a range of from 15% to 50% of the total radial height of the tread groove (30).