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 ¼ 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 ¼ 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 θ.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 θ.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 θ.sub.A>θ.sub.B.

A tire includes a tread portion that includes a center main groove, an outer main groove provided on an outer side in a tire width direction of the center main groove, and a lug groove extending in a direction intersecting with both main grooves. The center main groove has a zigzag shape in which a first linear portion and a second linear portion are alternately connected. The outer main groove has a zigzag shape in which a long linear portion and a short linear portion are alternately connected. The lug groove has a groove center line intersecting with the short linear portion in the zigzag shape of the outer main groove.

In a tire, a main groove has a bend where the groove wall angle relative to the tread surface normal line changes in a meridian cross-section. In first and second blocks adjacent in a width direction with the main groove therebetween, an angle between a line extended from a ridge line formed by a bend of a first block side groove wall and a line extended from a lug groove wall defining the first block is larger than an angle between a line extended from the ridge line formed by a bend of the second block side groove wall and a line extended from a lug groove wall defining the second block, and an angle of the first block side groove wall to the tread surface normal line is smaller than an angle of the second block side groove wall to the tread surface normal line.

In a tire including a block having an edge along a main groove closer to an equatorial plane and a block having an edge along a main groove farther from the equatorial plane, the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in a circumferential direction with the edge interposed therebetween are an acute angle (θa) and an obtuse angle (θb), and the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in the circumferential direction with the edge interposed therebetween are an acute angle (θc) and an obtuse angle (θd), with a relationship (θd−θc)<(θb−θa).

In a pneumatic tire, an inner second land portion includes chamfered portions and lug grooves. The chamfered portions are on an edge portion on a tire ground contact edge side of the inner second land portion and widen chamfer widths on a road contact surface of the inner second land portion in a tire circumferential direction. The lug grooves terminate in the inner second land portion at one end portion and open to central portions in a longitudinal direction of the chamfered portions at another end portion. An outer second land portion and an outer shoulder land portion include closed lug grooves terminating in the outer second land portion at one end portion. The closed lug grooves extend in the tire width direction and penetrate a circumferential narrow groove. The closed lug grooves terminate in a ground contact surface of the outer shoulder land portion at another end portion.

A tire comprises a tread portion whose shoulder land part is provided with a narrow circumferential groove having an axially inner wall surface, an axially outer wall surface and a groove bottom including a deepest point. The axially inner wall surface has a radially inner curved portion concaved toward the axially inside, and the axially outer wall surface has a radially inner curved portion concaved toward the axially outside. the radially outer end of the radially inner curved portion of the axially inner wall surface is positioned radially inside the radially outer end of the radially inner curved portion of the axially outer wall surface.

A tire includes a tread portion being provided with circumferential grooves extending continuously in a zigzag manner. One of the circumferential grooves includes first inclined elements inclined in a first direction with respect to the tire circumferential direction, second inclined elements inclined in a second direction opposite to the first direction with respect to the tire circumferential direction, and intersections where the first inclined elements and second inclined elements intersect. Each of the first inclined elements and the second inclined elements is provided with at least one first protrusion that projects outwardly in a tire radial direction from the groove bottom and connects the pair of groove walls. At least one of the intersections is provided with a second protrusion that projects outwardly in the tire radial direction from the groove bottom and is separated from the pair of groove walls.

A pneumatic vehicle tire, in particular utility vehicle tire, having a tread (2) which has a profiling and which has at least one circumferential groove (1) which runs in encircling fashion in the circumferential direction of the pneumatic vehicle tire and is formed to a profile depth PT.

At least over part of the circumference of the pneumatic vehicle tire, at least one circumferential groove (1) has a cross section perpendicularly to the circumferential direction that is made up of at least two groove portions adjoining one another in a radial direction R of the pneumatic vehicle tire. A first groove portion (4) is symmetrical with respect to the radial direction R of the pneumatic vehicle tire. The width of said groove portion in the axial direction A of the pneumatic vehicle tire is less than 3 mm and does not vary by more than 10%. A second radially inner groove portion (5) is made wider in the axial direction A in comparison with the first groove portion (4). It has the largest cross-sectional area of all the groove portions. Its cross-sectional area is asymmetrical to the radial direction R, extends on both sides of the radial direction R and has an edge without corners in the bottom region of the circumferential groove (1).

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.

A tyre for running on rough terrain includes a tread portion. The tread portion includes a crown region, middle regions, and shoulder regions. The crown region is provided with a plurality of crown blocks. The middle regions are provided with a plurality of middle blocks. The shoulder regions are provided with a plurality of shoulder blocks. Each of the middle blocks is connected with at least one of the crown blocks by a crown tie bar and connected with at least one of the shoulder blocks by a shoulder tie bar. A land ratio of the shoulder regions is 90% or more and 115% or less of a land ratio of the crown region.