The present invention provides a pneumatic tire and a rubber composition for tires, which have improved durability at high temperatures and during high-speed running while ensuring good ice performance. The present invention relates to a pneumatic tire, including a tread, the tread including blocks having an average ripe density of 1.0 cm/cm.sup.2 or higher and an average height of 0.6 to 2.0 cm, the blocks containing a rubber composition having a tan δ at 100° C. of 0.179 or less as determined at an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz, and has a ratio of the modulus at 100° C. to the modulus at room temperature of 69% or greater as determined in accordance with JIS K6251:2010.

Crown of a tire for a heavy vehicle that is desensitized to attacks. The tire (1) comprises tread (2) having a median degree of surface siping TL.sub.C, expressed in m/m.sup.2, equal to the ratio between the cumulative length L.sub.DC of the cuts (21), present in a median portion of tread of axial width W.sub.C, and the median area A.sub.C of the radially outer surface (23) of the tread (2), and protective reinforcement (4) comprising at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength R.sub.max, expressed in daN/m, such that the median degree of surface siping TL.sub.C of tread (2) is at least equal to 5 m/m.sup.2 and a coupling ratio C.sub.C, equal to the ratio between the maximum breaking strength R.sub.max and the median degree of surface siping TL.sub.C, is at least equal to 18 000 daN.

In a pneumatic tire, a center land comprises a plurality of center sipes, all of the center sipes are respectively contiguous with a first end and a second end in a tire axial direction of the center land, a first shoulder land comprises a plurality of first shoulder sipes, and all of the first shoulder sipes are contiguous with an outer end in the tire axial direction of the first shoulder land but are separated from an inner end in the tire axial direction of the first shoulder land.

The present invention provides for a heavy truck tire tread having a shoulder edge, shoulder groove, and shoulder rib therebetween. A plurality of sipes are in the shoulder rib and are oriented less than 20 degrees to the lateral direction. The sipes are spaced from one another between 5 to 18 millimeters in the longitudinal direction. Additionally or alternatively, the sipes are arranged so that a reference plane extends through a sipe bottom point and a sipe top point at the average sipe line. A sipe inclination line extends from the sipe bottom point to the sipe top point, and a reference line extends through the sipe bottom point. A sipe inclination angle is defined by the reference line and the sipe inclination line and is greater than 0 degrees.

Provided in a tread portion of a tire are main grooves, lug grooves intersecting the main grooves, and land portions defined by the main grooves. A specific one of the land portions includes, in a ground contact surface, sipes and narrow grooves intersecting the main grooves, the narrow grooves having a depth of 1.50 mm or less. When extending from one side toward another side in the width direction, the sipes and the narrow grooves have different directions extending in the circumferential direction in the central region and have the same direction extending in the circumferential direction in both edge regions on an outer side from the central region in the width direction. The specific one of the land portions includes at least one land portion on the outer side in the width direction.

A tire comprises a directional tread (10), said tread comprising a central axis (12) and two edges (14A, 14B) a tread width W being greater than or equal to 140 mm, said tread (10) comprising a plurality of patterns (13) which succeed one another in the circumferential direction, each pattern having a pitch P, the patterns (13) delimiting a plurality of oblique grooves (16A, 16B), each oblique groove extending from one of the edges (14A, 14B) of the tread as far as the central axis (12). In a central part of the tread centered on the central axis (12) and of a width corresponding to 80% of the width W of said tread, all or some of the oblique grooves (16A, 16B) of the plurality of oblique grooves have a prescribed slenderness ratio, and all or some of the patterns comprise at least one sipe and have a prescribed sipes density SD.

A pneumatic tire includes an inclined groove disposed in a first land portion and/or a second land portion which includes at least two bent portions. A sipe is disposed in the first land portion and/or the second land portion so as to intersect the inclined groove at 90°±30°. The sipe includes at least one bent portion.

The disclosure improves the wear resistance without impairing the on-ice performance. A tire is provided with a block divided by a lateral groove on a ground-contacting part. The block is provided with a plurality of sipes. The plurality of sipes are arranged in a thickness direction of the sipes. Each sipe has a pair of sipe walls that are separated in the thickness direction. Each sipe includes a protrusion that protrudes in a taper shape from one toward the other of the pair of sipe walls.

A tire has, on a tread surface of the tire, five land portions, an installation direction of the tire to a vehicle is designated, intermediate land portions respectively have a communicating sipe 40, the communicating sipe is constituted by a first sipe 41 at a vehicle-installed outside and a second sipe 42 at a vehicle-installed inside, the first sipe and the second sipe have an intersection point P on the vehicle-installed outside of a center line in a tire width direction of the corresponding intermediate land portion, the distance between the intersection point and a land portion edge at the vehicle-installed inside is the largest in an innermost intermediate land portion of the intermediate land portions, and an angle θ1 of the first sipe to a tire circumferential direction is larger than an angle θ2 of the second sipe to the tire circumferential direction.

In a pneumatic tire, a block includes recess/protrusions on a road contact surface. Additionally, a recess/protrusion content of the recess/protrusions is from 0.1 mm to 1.0 mm. A width of the recess/protrusions is from 0.1 mm to 0.8 mm. A recess/protrusion region is where an arrangement interval between adjacent recess/protrusions is not greater than 1.2 mm. A smooth region other than the recess/protrusion region has an arithmetic mean roughness of the road contact surface of the block not greater than 50 μm. A lateral length of the road contact surface of the block in a tire lateral direction is defined. In this case, the block includes the recess/protrusion region and the smooth region in an optional cross-section in a lateral range of not less than 40% of a lateral length of the road contact surface of the block.