A tire comprising a tread (10) is disclosed. The tread (10) comprises a plurality of circumferential grooves (20, 24) separating circumferential ribs, each groove (20, 24) comprising a bottom (21) and two sidewalls (22, 23); and one or more groove reinforcements (30, 31, 33, 34, 130). Each groove reinforcement is laterally spaced from any other of said one or more groove reinforcements. Each groove reinforcement (30, 31, 33, 34, 130) is arranged adjacent one circumferential groove (24). At at least one circumferential groove (20) has no groove reinforcement adjacent to it. Each groove reinforcement (30, 31, 33, 34, 130) extends from a radially inner surface of the tread (10) in a radially outward direction at least to the bottom (21) of the adjacent circumferential groove (20) to form at least part of the bottom (21) of that groove (20).