A tread for a tire includes a first circumferential main groove, a second circumferential main groove, a third circumferential main groove, and a fourth circumferential main groove. The fourth main groove has a stabilizing structure for increasing tread stiffness. The stabilizing structure has a circumferentially extending subgroove in a radially innermost bottom of the fourth circumferential main groove. The subgroove is axially offset a predetermined amount from a centerline of the fourth circumferential main groove.

The tire has a tread portion axially divided into two shoulder land regions, two middle land regions and one crown land region by two shoulder circumferential grooves and two crown circumferential grooves. The middle land regions are each provided with a single longitudinal sipe, and first and second middle transverse grooves extending from the adjacent shoulder circumferential groove and crown circumferential groove, and terminated without being connected to the longitudinal sipe. The shoulder land regions are each provided with shoulder transverse grooves extending from tread edges and terminated within the respective shoulder land regions.

A pneumatic tire is provided with, in the tread surface, land portions that include a rib or a plurality of blocks. The land portions are provided with a plurality of narrow shallow grooves and a plurality of recessed portions in a contact patch. Additionally, the opening area ratio Sc of the recessed portions in the central portion region in the tire lateral direction of one continuous contact patch and the opening area ratio Se of the recessed portions in the end portion regions in the tire lateral direction have the relationship Se<Sc, where the central portion region is defined as the region in the central portion in the tire lateral direction occupying 50% of the continuous contact patch of the land portions, and the end portion regions are defined as the regions in the left and right end portions in the tire lateral direction occupying 25%.

A pneumatic tire has inner mediate land portions and center land portion(s) that are divided into a plurality of blocks by lateral grooves. Each of the lateral grooves includes a pair of wide portions opening to a main groove and a narrow portion coupling the pair of the wide portions. one-side-closed sipes are formed in a bottom of each of the lateral grooves formed in the inner mediate land portions. The one-side-closed sipes are open at the wide portions and close at the narrow portion. a both-sides-open sipe is formed in a bottom of each of the lateral grooves formed in the center land portion or portions. The both-sides-open sipe is open at the wide portions and at the narrow portion.

A tread made of rubber-like material for a tire for winter travel having a plurality of blocks of a height H, each block comprising a contact face designed to come into contact with the ground when the tire travels and at least one lateral face, said lateral face being covered by a layer of covering material over at least 50% of the surface thereof, and a leading zone designed to come into contact first with the ground when the tire travels, and said block has an oblique direction of extension (J) such that the leading zone of said block is a leading corner, and a part which is not covered by the covering material, said covering material having a modulus of elasticity which is greater than the modulus of elasticity of the rubber-like material forming the block, said uncovered part extending from the leading corner over at least ⅓ of the height H of the block.

A passenger vehicle tire having rolling resistance without negatively affecting the grip and behaviour. The tread (2) has a radial height H.sub.S between 5 mm and 8 mm, a volumetric void ratio T.sub.EV between 22% and 30%, a total volume V.sub.CP of the main voids (241) at least equal to 80% of the total volume V.sub.C of the voids (24), and comprises an elastomeric compound having a glass transition temperature T.sub.g between 22° C. and 5° C., a Shore A hardness between 45 and 65, and a dynamic loss tgδ at 23° C. at least equal to 0.13 and at most equal to 0.39. The metal reinforcers of the working layers (41, 42) are steel monofilaments having a cross section S with a smallest dimension Dmin between 0.20 mm and 0.50 mm. The monofilaments distributed at a density d.sub.T between 100 threads/dm 200 threads/dm, each working layer (41, 42) having a mean radial thickness E.sub.T between D+0.1 mm and D+0.6 mm.

A tire has a carcass with a tread, a bead, a shoulder, and a sidewall. The bead, shoulder, and sidewall partially define a first internal cavity. At least one stiffening line for a pressurized fluid with a second cavity is within the carcass. The second cavity is aligned in an approximately transverse direction relative to the periphery of the tire. The second cavity is connectable to pressurized fluid supply system and can be inflated or deflated to adjust the stiffness of the tire. The stiffening lines may be inflated using a hydraulic fluid to increase the stiffness of the tire. Related wheels, vehicles, and methods are also disclosed.

A tyre includes a tread portion including a tread surface which is provided with grooves. At least one of the grooves includes a widening-width portion at least partially. The widening-width portion includes a first groove portion extending inwardly in a tyre radial direction from the tread surface, and a second groove portion located inwardly in the tyre radial direction of the first groove portion and having a groove width greater than that of the first groove portion.

A motorcycle tyre for traveling on rough terrain, the tyre includes a tread portion provided with blocks. The at least one of the blocks includes a ground contact surface having a pair of lateral edges extending in a tyre axial direction. The at least one of the blocks is provided with a pair of lateral narrow grooves extending in the tyre axial direction on the ground contact surface to form a pair of edge-side portions defined between the pair of lateral narrow grooves and the pair of lateral edges. The at least one of the pair of edge-side portions includes a neck portion having a minimum circumferential length thereof, wherein a circumferential length of the at least one of the pair of edge-side portions increases toward axially both sides from the neck portion.

A tyre includes a tread portion including a first middle land portion, a second middle land portion, a first shoulder land portion, and a second shoulder land portion. The first middle land portion is provided with first middle lateral grooves terminating within the first middle land portion, the second middle land portion is provided with second middle lateral grooves terminating within the second middle land portion, the first shoulder land portion is provided with first shoulder lateral grooves, and the second shoulder land portion is provided with second shoulder lateral grooves. The first middle lateral grooves and the second middle lateral grooves are inclined in a first direction with respect to the tyre axial direction, and the first shoulder lateral grooves and the second shoulder lateral grooves are inclined in a second direction opposite to the first direction with respect to the tyre axial direction.