A pneumatic tire comprising circumferential main grooves, a land portion defined by the circumferential main grooves, and a plurality of lug grooves disposed in the land portion that open to the circumferential main grooves. The land portion comprises notch portions formed on opening portions of the lug grooves and chamfered portions formed on edge portions of the notch portions. The notch portions have an edge portion with a V-shape projecting in a tire circumferential direction. A maximum width W2 of the notch portions and a width W3 of the chamfered portions have the relationship 0.30≦W3/W2≦1.80.

An object of the invention is to provide a tire having little change in riding comfort performance and wet performance before and after wear of the tread part and in which riding comfort performance and wet performance as when the tire is newly used are maintained. The fire comprises a tread being composed of a rubber layer in which there is little change in hardness after thermal deterioration and having a groove shape such that a sea ratio after wear with respect to a sea ratio as when the tire is newly used is within a predetermined range.

An object of the invention is to provide a tire having good steering stability performance after wear and in which a decrease in wet performance after wear is suppressed. The tire comprises a tread being composed of a rubber layer in which change in hardness after thermal deterioration is within a predetermined range and having a groove shape such that a sea ratio after wear with respect to a sea ratio as when the tire is newly used.

A pneumatic tire is provided. A tread portion includes shallow grooves formed in a road contact surface of each of shoulder blocks, intermediate blocks, and center blocks, defined by a plurality of longitudinal grooves extending in a tire circumferential direction and a plurality of lateral grooves extending in a tire lateral direction, the shallow groove having a smaller groove depth than the longitudinal groove and the lateral groove. The shallow groove extends along the tire lateral direction, and at least one end thereof communicates with the longitudinal groove or the lateral groove. A contour line of the shallow groove is provided with at least one bend point. A sipe is provided in a flat bottom surface of the shallow groove extending along the shallow groove. Among the shallow grooves, center shallow grooves formed in the center block are each provided with a terminating end portion terminating in the center block.

A tire includes, in a tread portion, a pair of shoulder main grooves, a crown region between the shoulder main grooves, and shoulder regions disposed outside of the shoulder main grooves in a tire axial direction. Land ratios of the crown region and the shoulder regions are respectively 40%-60%. In the crown region, a plurality of middle blocks are arranged on both sides of a tire equator, and each middle block has a longitudinal shape in which a length in the tire circumferential direction is larger than a length in the tire axial direction.

A tire comprises a tread provided with two edges (25A, 25B) and with a center (C) dividing it into two parts of equal width with sets of blocks (21A, 21B). Each set of blocks (21A, 21B) comprises three zones: at the edge (211), at the center (213) and intermediate (212). Each set of blocks (21A, 21B) comprises a set of chamfers (26A, 26B, 26C) which extends over at least the edge zone (211) and the central zone (213) of the set of blocks (21A, 21B). The width LC1 of the set of chamfers (26A, 26B, 26C) over the edge zone (211) is different from the width LC2 of the set of chamfers (26A, 26B, 26C) over the intermediate zone (212), the widths LC1 and LC2 being comprised between 0.5 mm and 2.5 mm.

A tire comprises a directional tread provided with two edges (25A, 25B) and with a center (C) dividing it into two parts of substantially equal width. The tread comprises, on one of these two parts, blocks (21A, 21B) succeeding one another in a circumferential direction. Each block (21A, 21B) has a leading-edge face (26) and a trailing-edge face (27). The tire comprises, for at least one set of blocks (21A, 21B), at least one set of cavities (29) extending over the trailing-edge face (27) of the set of blocks (21A, 21B). The tread has a bottom surface (24) radially on the inside of the tread, the set of blocks (21A) having a height H, wherein the set of cavities (29) is between the bottom surface (24) of the tread and half of the height H.

A tire includes a tread portion provided with at least one circumferentially extending zigzag main groove having a groove bottom, the at least one main groove including first inclined portions, second inclined portions each inclined in an opposite direction to the first direction, and first intersections where the first inclined portions and the second inclined portions are communicated with each other. The first inclined portions and the second inclined portions are arranged alternately in the tire circumferential direction. The first inclined portions are longer than the second inclined portions. The groove bottom of the at least one main groove is provided with at least one protruding part extending in a width direction of the at least one main groove, and a distance between the at least one protruding part and one adjacent first intersection is equal to or less than 2 times groove widths of the first intersections.

A pneumatic tire can suppress uneven wear of the tire and improve the performance on snow. A plurality of inner side circumferential grooves (11a, 11b, 11c) arrayed between a pair of outermost side circumferential grooves (11d, 11d) have a groove width that is smaller than that of the outermost side circumferential grooves (11d) to such a degree allowing land portions on the opposite sides thereof to come into contact with each other upon grounding. A plurality of recessed portions (S) of a shape cut in a radial direction from a tread face are formed along the tire circumferential direction on opposing block wall faces (14Af, 14Bf) of blocks (14A, 14B) on the opposite sides of at least one (11b) of the inner side circumferential grooves.

A tire for running on rough terrain has a tread portion provided with crown blocks, middle blocks, and groove portions. Each of the crown blocks includes a ground contacting surface and a first wall surface located on a heel side in a tire rotational direction. The first wall surface is inclined to a toe side in the tire rotational direction as it goes inward in a tire radial direction from the ground contacting surface. Each of the groove portions has a length in the tire axial direction of 5% or more and 70% or less of a length in the tire axial direction of each of the middle blocks.