Tire tread and a tire comprising a tread

A tire tread having circumferential grooves, each circumferential groove having a bottom, and an outer radial surface, the tread further comprising:

• a tread cap comprising a first rubber compound which is adapted to be ground contacting when driving, at least one circumferential groove reinforcement forming at least one reinforced groove in the tread cap, the groove reinforcement comprising a second rubber compound for reinforcing an area adjacent the grooves formed by the groove reinforcement, wherein the groove reinforcement comprises for at least one reinforced groove formed by the groove reinforcement:
• two groove sidewall layers, each of the two groove sidewall layers extending from the outer radial surface of the tread down into the direction of the bottom of the groove formed by the groove reinforcement and wherein each of the two groove sidewall layers of the groove reinforcement has an essentially uniform thickness along its length, and
• a groove support portion forming a bottom portion of the groove and having a radially inner base side as well as a radially outer top side, wherein the groove support portion tapers from its base side to its top side, wherein the groove support portion has an essentially trapezoidal shape tapering from the base side to the top side wherein the base side and the top side are interconnected at their lateral edges by lateral sides, wherein the lateral sides are at an angle α to the base side which is smaller than 90°, wherein the support portion has a radial height which is at least 15% of the distance between the bottom of the groove and the inner radial side of the tread base layer as measured radially below the reinforced groove, and wherein the angle θ between the lateral side of the support portion and each of the two groove sidewall layers of the groove reinforcement is smaller than 180°.