A tire comprises a tread portion 2 comprising a shoulder main groove 5 extending on a side of a tread edge Te and comprising inner and outer groove walls 11 and 12. The inner groove wall 11 has an angle 1 with respect to a tread normal line in a cross section of the shoulder main groove 5 periodically increasing and decreasing in a tire circumferential direction so as to comprise concave and convex wall portions 16 and 17 arranged alternately in the tire circumferential direction. The outer groove wall 12 has an angle 2 with respect to a tread normal line in the cross section periodically increasing and decreasing in the tire circumferential direction so as to comprise convex and concave wall portions 22 and 21 arranged alternately in the tire circumferential direction. The angle 2 is larger than the angle 1 in any cross section of the groove.

A tire comprises a tread portion 2 comprising a shoulder main groove 5 extending on a side of a tread edge (Te). The shoulder main groove 5 comprises an inner groove wall 11 having an angle with respect to its tread normal line in a cross section of the shoulder main groove 5 periodically increasing and decreasing in a tire circumferential direction so that the inner groove wall 11 comprises concave wall portions 16 and convex wall portions 17 arranged alternately in the tire circumferential direction. The concave wall portions 16 are provided at inner end portions thereof in a tire axial direction with recess portions 20 locally recessed inwardly in the tire axial direction and having openings at a ground contacting surface of the tread portion 2.

A tread includes a plurality of circumferential grooves. Each of the plurality extends continuously in a tire circumferential direction. The plurality of circumferential grooves defining a circumferentially extending main rib and a circumferentially extending curtain rib axially separated by a curtain groove. The curtain groove having an axial width between 4% and 40% of a minimum axial width of a main groove of the plurality of circumferential grooves. The main groove is disposed axially opposite the curtain groove and adjacent to the curtain rib.

A heavy-duty tire includes a tread part formed such that the tread part includes a crown profile including tire equator, and a pair of shoulder profiles extending from outer sides of the crown profile to tread edges. In a tire cross section including tire rotation axis in 5% internal pressure state in which the tire is mounted to a normal rim, filled with air at internal pressure of 5% of normal internal pressure and loaded with no load, each of the crown and shoulder profiles has an arc shape convex toward tire radial direction outer side such that ratio Rc/Rs of curvature radius Re of the crown profile to curvature radius Rs of each shoulder profile is 7.0 or more, and a tire axial direction distance from the equator to a connecting point between the crown profile and each shoulder profile is 0.70 or more times a tread half width.

A tread pattern of a pneumatic tire includes one center continuous land portion and two intermediate continuous land portions that are divided by four circumferential main grooves and that are not provided with lug grooves. Edges on both sides of one center main groove include groove chamfered portions having a chamfered width changing in the circumferential direction in a zigzag shape. In the regions of the intermediate continuous land portions, first sipes extending inward in the lateral direction from shoulder main grooves of the main grooves, which are positioned on outer sides in the lateral direction, are provided. The first sipes each include a sipe main body portion having a constant distance between sipe wall surfaces on a sipe bottom side and a sipe chamfered portion inclined so that the sipe wall surfaces are open toward the tread surface.

Tire tread including one or more tread elements arranged between a pair of discontinuities extending in a direction of the tread width. The first and second longitudinally-spaced sides of the tread element are spaced-apart in a direction of the tread length. The first longitudinally-spaced side is oriented at an average first-side angle relative to the depthwise direction of the tread and the second longitudinally-spaced side is oriented at an average second-side angle relative to the depthwise direction of the tread. An average inclination angle comprising a combined average of the average first side-angle and the second side-angle for all of the one or more tread elements along the first and second longitudinally-spaced sides is substantially greater than zero.

A tire comprises a tread portion for which an intended tire rotational direction is specified. The tread portion comprises rows composed of blocks circumferentially divided by lateral grooves. Each block has a ground contacting top surface, and a first side wall surface and a second side wall surface located on a heel-side and a toe-side, respectively, in the intended tire rotational direction. In a cross section of each block which is parallel with the tire circumferential direction, the first and second block-side wall surfaces are both inclined, and the angle 2 of the second side wall surface is larger than the angle 1 of the first side wall surface with respect to the tire radial direction. The difference 21 between the angles 2 and 1 increases toward one side in the tire axial direction.

Provided is a motorcycle pneumatic tire in which the wet grip performance is improved while the steering stability during turning is ensured. The motorcycle pneumatic tire includes, on its ground-contact surface: a first inclined groove (21) that extends on a tire width-direction outer side from the vicinity of a tire equator and is inclined in the same direction as a tire rotation direction; and a short groove (22) that is arranged on the extension of a tire width-direction outer end of the first inclined groove (21). The tire width-direction outer end of the first inclined groove is positioned in the vicinity of a point at of a tread width (TW) from the tire equator on the tire width-direction outer side, while a tire width-direction inner end of the short groove is positioned in a range of to 5/16 of the tread width (TW) from the tire equator on the tire width-direction outer side; an inclination angle of the first inclined groove with respect to a tire circumferential direction increases toward the tire width-direction outer side; and an angle .sub.A formed by a groove wall of the tire width-direction outer end of the first inclined groove with respect to the direction perpendicular to the tire surface, and an angle .sub.B formed by a groove wall of the tire width-direction inner end of the short groove with respect to the direction perpendicular to the tire surface, satisfy a relationship of .sub.A>.sub.B.

A shoulder land portion is sectioned into a main land portion and a sacrificed land portion by a narrow groove extending in a tire circumferential direction. A groove bottom portion of the narrow groove is formed by depressing a groove wall in the tread center side. A contour of the main land portion is formed by a first circular arc in a tread center side and a second circular arc in a tread end side. A radius of curvature R1 of the first circular arc is less than a radius of curvature R2 of the second circular arc. A ratio W/d satisfies a relationship 2W/d6. The d is a depression width of a groove bottom portion. The W is a distance from a tread end side edge of the main land portion to a boundary between the first circular arc and the second circular arc.

A pneumatic tire includes a shoulder land portion and a narrow groove in a tread surface. The narrow groove extends in the tire circumferential direction and sections the shoulder land portion into a main land portion and a sub land portion. A first groove portion extends in parallel to the tire equator surface from the tread surface toward an inner side in a tire radial direction. A second groove portion is provided closer to the inner side in the tire radial direction and the tire equator surface side than the first groove portion, and extends in parallel to the tire equator surface. A connection portion is connected to the first groove portion and the second groove portion. A groove bottom portion is provided in an end portion of the second groove portion and has a widened groove width by depressing a groove wall of the second groove portion.