A tire comprising: a tread portion with a groove portion formed to extend in a tire circumferential direction (tcd); a plurality of protrusion portions provided on a groove bottom (50B2) of the groove portion, each of the protrusion portions extending from one side walls forming the groove portion to the other side wall (50B3) opposed to the one side wall (50B1), the protrusion portions arranged at predetermined intervals in the groove portion, wherein a relationship of 0.75L ≤ P ≤ 10L is satisfied when a length of the protrusion portion along a groove center line passing through a center in a width direction of the groove portion is L, and the predetermined interval is P, in a tread surface view of the tire, further comprising a plurality of belt layers arranged in the tread portion and extending in a tire circumferential direction (tcd); a pair of bead cores; and a carcass layer which extends across the pair of the bead cores and has a toroidal shape, wherein the plurality of belt layers include a shortest belt layer whose length in a tread width direction (twd) is smallest, characterised in that, a length along the tread width direction (twd) from an end of the shortest belt layer in the tread width direction (twd) to the groove center line is not more than 200 mm, and the plurality of belt layers comprises an inner crossing belt group comprising a set of two belt layers (31, 32) and located outside the carcass layer in a tire radial direction (trd), an intermediate crossing belt group comprising another set of two belt layers (33, 34) and located outside the inner crossing belt group in the tire radial direction (trd), and an outer crossing belt group comprising still another set of two belt layers (35, 36) and located outside the intermediate crossing belt group in the tire radial direction (trd), and the inner crossing belt group includes the shortest belt layer. a tread portion with a groove portion formed to extend in a tire circumferential direction (tcd); a plurality of protrusion portions provided on a groove bottom (50B2) of the groove portion, each of the protrusion portions extending from one side walls forming the groove portion to the other side wall (50B3) opposed to the one side wall (50B1), the protrusion portions arranged at predetermined intervals in the groove portion, wherein a relationship of 0.75L ≤ P ≤ 10L is satisfied when a length of the protrusion portion along a groove center line passing through a center in a width direction of the groove portion is L, and the predetermined interval is P, in a tread surface view of the tire, further comprising a plurality of belt layers arranged in the tread portion and extending in a tire circumferential direction (tcd); a pair of bead cores; and a carcass layer which extends across the pair of the bead cores and has a toroidal shape, wherein the plurality of belt layers include a shortest belt layer whose length in a tread width direction (twd) is smallest, characterised in that, a length along the tread width direction (twd) from an end of the shortest belt layer in the tread width direction (twd) to the groove center line is not more than 200 mm, and the plurality of belt layers comprises an inner crossing belt group comprising a set of two belt layers (31, 32) and located outside the carcass layer in a tire radial direction (trd), an intermediate crossing belt group comprising another set of two belt layers (33, 34) and located outside the inner crossing belt group in the tire radial direction (trd), and an outer crossing belt group comprising still another set of two belt layers (35, 36) and located outside the intermediate crossing belt group in the tire radial direction (trd), and the inner crossing belt group includes the shortest belt layer.