A tire comprising: a tread portion having a pair of tread edges (Te), a tread surface extending between the tread edges (Te) and a pair of buttress surfaces extending axially outwardly from the respective tread edges (Te), the tread portion comprising a tread rubber including a radially outermost first rubber layer forming the tread surface and made of a first cap rubber compound, and a second rubber layer disposed on the radially inside of the first rubber layer and made of a second cap rubber compound, wherein the buttress surfaces have inclinations such that the tread edges (Te) shift axially outwards as the tread rubber is worn off, characterized in that a loss tangent δ2 of the second cap rubber compound is larger than a loss tangent δ1 of the first cap rubber compound, one of, or alternatively, each of the buttress surfaces is provided with an outer lateral groove extending in a tire axial direction, and the outer lateral groove is arranged axially outside the tread edge (Te) from which the buttress surface extends axially outwards so that, when the tread edge (Te) shifts axially outwards due to wear of the tread rubber, the outer lateral groove is at least partially positioned axially inside the tread edge (Te), with the loss tangent values (tanδ) measured according to JIS K6394 under tensile deformation at an initial strain of 5%, with a dynamic strain amplitude of +/-1%, at a frequency of 10Hz, at a temperature of 30° Celsius. the tread portion comprising a tread rubber including a radially outermost first rubber layer forming the tread surface and made of a first cap rubber compound, and a second rubber layer disposed on the radially inside of the first rubber layer and made of a second cap rubber compound, wherein the buttress surfaces have inclinations such that the tread edges (Te) shift axially outwards as the tread rubber is worn off, characterized in that a loss tangent δ2 of the second cap rubber compound is larger than a loss tangent δ1 of the first cap rubber compound, one of, or alternatively, each of the buttress surfaces is provided with an outer lateral groove extending in a tire axial direction, and the outer lateral groove is arranged axially outside the tread edge (Te) from which the buttress surface extends axially outwards so that, when the tread edge (Te) shifts axially outwards due to wear of the tread rubber, the outer lateral groove is at least partially positioned axially inside the tread edge (Te), with the loss tangent values (tanδ) measured according to JIS K6394 under tensile deformation at an initial strain of 5%, with a dynamic strain amplitude of +/-1%, at a frequency of 10Hz, at a temperature of 30° Celsius. the buttress surfaces have inclinations such that the tread edges (Te) shift axially outwards as the tread rubber is worn off, characterized in that a loss tangent δ2 of the second cap rubber compound is larger than a loss tangent δ1 of the first cap rubber compound, one of, or alternatively, each of the buttress surfaces is provided with an outer lateral groove extending in a tire axial direction, and the outer lateral groove is arranged axially outside the tread edge (Te) from which the buttress surface extends axially outwards so that, when the tread edge (Te) shifts axially outwards due to wear of the tread rubber, the outer lateral groove is at least partially positioned axially inside the tread edge (Te), with the loss tangent values (tanδ) measured according to JIS K6394 under tensile deformation at an initial strain of 5%, with a dynamic strain amplitude of +/-1%, at a frequency of 10Hz, at a temperature of 30° Celsius.