A pneumatic tire comprises a tread portion provided with a central main groove, an outboard shoulder main groove and an inboard shoulder main groove extending continuously in the tire circumferential direction. The central main groove and the inboard shoulder main groove are each connected to grooves and/or sipes. The outboard shoulder main groove is widest and not connected to any grooves inclusive of a sipe or a very narrow groove. On both sides of the outboard shoulder main groove, there are formed sloping surfaces extending from the respective groove edges and merging into the tread surface. The width of each sloping surface is more than the depth thereof.

In the tire (1), a region of the tread portion (10) overlapping with a range of 80% of a length of the circumferential belt layer (40) in a tread widthwise direction around a tire equator line CL is a central region CR in the tire radial direction trd, and a remaining region of the tread portion (10) is a terminal region TR, a maximum curvature radius of the arc portion of the central circumferential groove 50a is R1, a minimum curvature radius of the arc portion of the terminal circumferential groove 50b is R2, a maximum depth in the tire radial direction trd from the tread surface (11) to a groove bottom 55a of the central circumferential groove 50a is D1, a maximum depth in the tire radial direction trd from the tread surface (11) to a groove bottom 55b of the terminal circumferential groove 50b is D2, and a relationship of R1/D10.130 and a relationship of R2/D2>0.195 are satisfied.

A precured tread assembly for mounting on a tire casing is provided. The precured tread assembly includes a tread portion having a mounting surface and an opposing ground-engaging surface with a plurality of grooves therein. A reinforcing fabric layer is attached to the mounting surface of the tread portion.

Tire (1) for a heavy vehicle of construction plant type with tread (2) comprising raised elements (3), separated by grooves (4), extending radially outwards from a bottom surface (5) as far as a contact face (6) over a height (H) and comprising base compound (9) and coating compound (10). Coating compound (10) has a constant maximum thickness (e.sub.max), at the contact face (6) of each raised element (3), at most equal to 0.15 H, the coating compound (10) has a constant minimum thickness (e.sub.min), at each groove bottom (8), at least equal to 0.04 H, and the elongation at break at 23 C. A.sub.R2 of the coating compound (10) is at least equal to 1.05 times the elongation at break of 23 C. A.sub.R1 of the base compound (9).

A tire 1 includes a pair of shoulder block rows 4, 4 and a plurality of crown blocks 5. The crown blocks 5 include a plurality of first crown blocks 7 and a plurality of second crown blocks 8 which are disposed such that a second crown block pair 9 having the two second crown blocks 8 disposed adjacent to each other in the tire axial direction repeatedly appears in the tire circumferential direction. Each first crown block 7 is disposed one by one between the second crown block pairs 9 adjacent to each other in the tire circumferential direction. The first crown block 7 has a laterally elongated tread surface 7a in which the maximum length L1 is less than the maximum width W1. The second crown block 8 has a longitudinally elongated tread surface 8a in which the maximum length L2 is greater than the maximum width W2.

A tire includes main grooves and rows of lands. At least one of the main grooves has a groove wall angle on a vehicle inner side smaller than a groove wall angle on a vehicle outer side. The rows of lands include center, intermediate, and shoulder lands. Shoulder lug grooves in at least one of the shoulder lands communicate with the main groove. The intermediate lands include intermediate lug grooves opening to the main groove and terminating within the intermediate lands, first sipes opening to the main groove and to the intermediate lug grooves, and second sipes opening to the main groove located opposite to the main groove to which the intermediate lug grooves open and opening to the intermediate lug grooves. The first and second sipes each include a chamfer on only one of a step-in side edge or a kick-out side edge.

A belt layer includes an inner cross belt having a belt cord angle with an absolute value of 45 degrees or more relative to the circumferential direction, an outer cross belt having a belt cord angle with an absolute value of 45 degrees or less relative to the circumferential direction with an opposite sign as the belt cord angle of the inner cross belt and outward of the inner cross belt in the radial direction, and a circumferential reinforcing layer including a belt cord having a belt angle within 5 degrees relative to the circumferential direction and disposed between the inner and outer cross belts. A width W1 of the circumferential reinforcing layer in the width direction, a width W2 of the inner cross belt in the width direction, and a width W3 of the outer cross belt in the width direction satisfy a relationship W1<W3<W2.

A tread block arrangement is suitable for a tire or for a tread band for a tire. The tread block arrangement includes a tread block having a first sipe delimited by a first sipe wall, a second sipe wall and a bottom of the sipe. The first sipe wall and the second sipe wall are arranged parallel to each other and define a width of the sipe. At least the first sipe wall has an indentation to increase an empty volume of the sipe at the location of the indentation. The first sipe wall has an inclined section to form the indentation, wherein a distance between the first sipe wall and the second sipe wall increases towards the bottom of the sipe at the location of the inclined section. A tire has the tread block arrangement and a lamella plate for forming sipes of the tread block arrangement.

Provided is a pneumatic tire. A chamfered portion and a non-chamfered portion are provided in each of an edge on a leading side and an edge on a trailing side of a sipe. In a meridian cross-sectional view, a profile line of a rib projects further to an outer side in a tire radial direction than a reference tread profile line. A radius of curvature TR of the reference tread profile line and a radius of curvature RR of the profile line satisfy TR>RR. Only one of the chamfered portions on the leading side and the trailing side is disposed so as to straddle a maximum projection position. A maximum projection amount D of the rib with respect to the reference tread profile line and a maximum width W of the chamfered portion satisfy 0.05 mm.sup.2<WD<1.50 mm.sup.2.

An object of the present invention is to improve propulsion performance on a snow-covered road surface, and provided is a tire with a tread portion having a groove, wherein the cap rubber layer forming the tread portion contains 40 parts by mass or more and 80 parts by mass or less of styrene-butadiene rubber (SBR) having a styrene content of 25% by mass or less in 100 parts by mass of its rubber component, and 60 parts by mass or more of a filler with respect to 100 parts by mass of the rubber component, and is formed from a rubber composition having a loss tangent 10 C. tan measured under the conditions of temperature of 10 C., frequency of 10 Hz, initial strain of 5%, and dynamic strain rate of 1% and in deformation mode; tensile of less than 0.28, and a glass transition temperature Tg ( C.) of 40 C. or lower; and the glass transition temperature Tg ( C.) and the depth G (mm) of the groove satisfy Tg0.5G35.