Taking a groove side-wall to a position at a groove depth from a tread face of lug groove as a tread-in side first inclined portion, and taking a groove side-wall from the position at groove depth to a groove bottom as a tread-in side second inclined portion, then the following A1 is set less than the following B1. When viewed in cross-section orthogonal to a length direction of the lug groove: A1 is an area of a region enclosed by an imaginary line passing through an end portion on a tread face side of the tread-in side first inclined portion and perpendicular to the tread face, by an imaginary line passing through an end portion on a groove bottom side of the tread-in side first inclined portion and orthogonal to the imaginary line, and by the tread-in side first inclined portion; and B1 is an area of a region enclosed by an imaginary line passing through an end portion on a tread face side of the tread-in side second inclined portion and perpendicular to the tread face, by an imaginary line passing through the deepest portion of the lug groove and parallel to the tread face, and by the tread-in side second inclined portion.

By forming a ground contact edge side of lug grooves such that the groove depth becomes shallower in groove depth from the tire equatorial plane side toward the ground contact edge, and by setting an average angle of inclination formed between a tread face and a groove bottom to be not more than 5, water expulsion is performed smoothly in the vicinity of the ground contact edge while securing the rigidity of land portions in the vicinity of the ground contact edge. This enables a high degree of both wet performance and dry performance to be achieved.

The invention relates to a tyre with improved performance in terms of transverse grip on snow-covered surfaces without a resulting impairment in performance in terms of grip on wet and dry surfaces. The tread is obtained by repeating the tread pattern elements (MA, MB) at pitches (PA, PB) over a complete circuit of the tyre, with PA<PB. Each first lateral portion (ZB) of said tread pattern elements contains at least one longitudinal sipe (50) of which the path on the tread surface (15) is a mean plane (53) that makes an angle Beta with the circumferential direction, which angle is comprised within the range [0?, 20?]. This same mean plane (53) also makes an angle Alpha with the direction (Npsup) normal to the tread surface (15), which angle is comprised within the range [3?; 55?], and the sum of the projected lengths of the longitudinal sipes (50) in the circumferential direction onto all of the first lateral portions (ZB) is comprised between 0.5 times and 5 times the circumference of the tyre measured in the equatorial plane.

A tread (10) for a heavy truck tire is provided that has an upper surface for engaging the ground, a leading edge, and a trailing edge forward of the leading edge in a rolling direction. The tread also has a J shaped sipe (30) that has a main portion (32) that extends from the upper surface. The main portion (32) has an opening at the upper surface and a bottom end (36) opposite the opening in a radial direction. A curved portion (38) extends from the bottom end (36) and has a bottom curved wall (40) that has a radius (r1). The curved portion (38) extends from the bottom end (36) forward in the rolling direction (24), and has a curved portion end (42).

The present invention is directed to a pneumatic tire 1, comprising at least one pair of parallel annular beads 3; at least one carcass ply wrapped 5 around said beads 3; a tread 7; and first and second sidewalls 9 disposed between said tread 7 and one of said at least one pair of beads 3. In accordance with an embodiment of the invention, the tread comprises tread blocks 11 and/or tread ribs 12, wherein the tread blocks 11 and/or tread ribs 12 comprise sipes 13 extending essentially in an axial direction A of the tire 1, the sipes 13 consisting of an upper portion 15 essentially aligned with the radial direction R of the tire and a lower portion 17 inclined in the direction of rotation D of the tire 1.

A method of mounting a tire on a vehicle includes providing a tire having a first side, a second side, and a circumferential tread disposed about the tire. The first side defines a first forward rotation direction and the second side defines a second forward rotation direction. The circumferential tread includes a plurality of tread elements, and at least one of the plurality of tread elements includes a sipe arrangement including a plurality of sipes that are angled in a depth direction of the tire. The plurality of sipes are disposed on a first half of the tread element and no sipes are disposed on a second half of the tread element. The sipe arrangement causes the tire to exhibit a first tire performance when the tire is mounted on the vehicle in the first orientation and rotated in the first forward rotation direction, and further causes the tire to exhibit a second tire performance when the tire is mounted on the vehicle in the second orientation and rotated in the second forward rotation direction. The method includes mounting the tire on the vehicle in the first orientation for driving the vehicle in a first set of conditions, and mounting the tire on the vehicle in the second orientation for driving the vehicle in a second set of conditions.

A heavy truck tire tread is provided that has an outer surface and a circumferential groove (24) that extends in the circumferential direction completely around the tread. A rib (26) is present that has a rib element (28) that defines a portion of the circumferential groove (24) and has an upper surface (30) in the radial direction. The upper surface has a leading edge (32) and a tailing edge (34) in the circumferential direction. The leading edge (32) and the tailing edge (34) are at different distances to the central axis in the radial direction. A first micro sipe (40) extends into the rib and opens into the circumferential groove (24), and a second micro sipe (42) extends into the rib (26) and opens into the circumferential groove (24). The rib element (28) extends from the first micro sipe (40)) to the second micro sipe (42) in the circumferential direction.

A heavy truck tire tread is provided that has a rolling direction that is in a longitudinal direction of the tread. A circumferential sipe (20) is present and extends in the longitudinal direction completely around the tread. The circumferential sipe does not bound a sacrificial rib. A plurality of micro sipes (22) engage the circumferential sipe and are located on opposite sides of the circumferential sipe in the lateral direction. The micro sipes extend from the circumferential sipe so as to terminate within rubber of the tread at a terminal end.

A tread for a heavy truck tire is provided that has a shoulder rib (22) with a shoulder rib upper surface (24), and a sacrificial rib (26) with a sacrificial rib upper surface (28). The sacrificial rib (26) is located outboard from the shoulder rib (22) in the lateral direction and engages the shoulder rib (22) such that an interface is present at engagement of the sacrificial rib and the shoulder rib. The sacrificial rib upper surface (28) is located closer to the central axis in the radial direction than the shoulder rib upper surface (24) is located to the central axis in the radial direction. A plurality of decoupling sipes (32) in the shoulder rib (22) extend through the interface and into the sacrificial rib (26). The decoupling sipes (32) are spaced from one another in the circumferential direction such that immediately successive ones of the decoupling sipes (32) are not in engagement at the interface.

A tread profile of a vehicle tire has profile positives such as profile blocks or tread bands that have sipes. The sipes have an approximately -shaped geometry in plan view having two axial sections which are arranged approximately in an axial direction and which are arranged on a common, imaginary straight line with a spacing (a) to one another; a central bulge arranged between the axial sections, wherein the bulge has a maximum extent (b) measured in the axial direction; and, wherein a<b, such that undercuts are formed.