Tread (1) for a heavy-duty vehicle tire having a total thickness corresponding to the thickness of material to be worn away during running, this tread having, in the new state, a tread surface (10) intended to come into contact with a roadway when running. The tread comprises at least one hidden cavity (2) forming a new groove opening onto the tread surface after a predetermined amount of partial wear. Cavity (2) comprises two opposite lateral walls (21, 22) connected together by bottom (23) radially towards the inside and by crown part (24) radially towards the outside. Crown part (24) is provided with a plurality of fine grooves (25) extending radially towards the outside from crown part (24) delimiting the cavity and extending in a direction that makes an angle at least equal to 40 degrees with the main direction of cavity (2).

A tyre includes a crown land portion, an outboard middle land portion, an outboard shoulder land portion, an outboard crown circumferential groove, an outboard shoulder circumferential groove, an inboard middle land portion, an inboard shoulder land portion, an inboard crown circumferential groove, and an inboard shoulder circumferential groove. The outboard middle land portion is provided with full-opened outboard middle sipe that are inclined to a tyre axial direction. The outboard middle sipes each have two opposite sipe-edge portions provided with chamfer portions. In each chamfer portion of each outboard middle sipe, chamfer widths at both ends of the outboard middle sipe are larger than a chamfer width of a central portion of the outboard middle sipe. The outboard shoulder land portion is provided with outboard shoulder sipes that are inclined in the same direction as the outboard middle sipes to the tyre axial direction.

A car tyre having a tread that extends in axial direction for a width the tread including a central portion arranged across an equatorial plane, and two lateral portions opposed with respect to the central portion. The central portion is separated from the lateral portions of the tread by two circumferential grooves. The circumferential grooves have a width greater than about 6 mm. The central portion extends in axial direction for a width less than 20% of the width of the tread and includes a plurality of first sipes. Each lateral portion has a width greater than 30% of the width of the tread, and each lateral portion includes, furthermore, a plurality of transversal grooves. The transversal grooves of a lateral portion include at least a first inclined length that extends from a zone proximal to the respective circumferential grooves, moving away from the equatorial plane. The first inclined length has an inclination 60 with respect to equatorial plane. Each lateral portion includes a plurality of sipes. The density of the sipes decreases moving away from the equatorial plane.

In a pneumatic tire, land portions have a plurality of sipes and at least one row of land portions in an inner side region is provided with sipes having a 3D structure. Also, the snow traction index (STI) with respect to the tire circumferential direction throughout the entire tread portion is in the range of 100STI. Also, the sipe component (STI_s_out) of the snow traction index (STI) in an outer side region and the sipe component (STI_s_in) of the snow traction index (STI) in the inner side region have the relationship of 1.1STI_s_in/STI_s_out. Also, the peripheral length ratio PLR_out of the three-dimensional structure portion in the outer side region and the peripheral length ratio PLR_in of the three-dimensional structure portion in the inner side region have the relationship of 1.1PLR_in/PLR_out.

A car tire having a tread that extends in axial direction for a width the tread including a central portion arranged across an equatorial plane, and two lateral portions opposed with respect to the central portion. The central portion is separated from the lateral portions of the tread by two circumferential grooves. The circumferential grooves have a width greater than about 6 mm. The central portion extends in axial direction for a width less than 20% of the width of the tread and includes a plurality of first sipes. Each lateral portion has a width greater than 30% of the width of the tread, and each lateral portion includes, furthermore, a plurality of transversal grooves. The transversal grooves of a lateral portion include at least a first inclined length that extends from a zone proximal to the respective circumferential grooves, moving away from the equatorial plane. The first inclined length has an inclination 60 with respect to equatorial plane. Each lateral portion includes a plurality of sipes. The density of the sipes decreases moving away from the equatorial plane.

A tyre comprises a tread portion comprising a shoulder main groove and a shoulder land region. The shoulder land region includes an outer region, a middle region, and an inner region. The shoulder land region is provided with a plurality of shoulder sipes having components in a tyre axial direction. A sipe ratio of the middle region is smaller than the sipe ratio of the outer region and the sipe ratio of the inner region.

A tread pattern of a pneumatic tire includes three or more circumferential main grooves extending in a tire circumferential direction, a plurality of lug grooves provided in a land portion defined by two circumferential main grooves, and a sipe provided between adjacent lug grooves. The sipe is a composite sipe having a two-dimensional portion and a three-dimensional portion. Among open ends on both sides of the lug groove, an open end on an identical side to an end portion of the sipe at which the two-dimensional portion is provided is provided with a raised bottom portion.

In a pneumatic tire, a tread rubber includes a vehicle inner side region, a vehicle outer side region, first stereoscopic sipes, and second stereoscopic sipes. The first stereoscopic sipe has a sipe wall surface of a shape bent in a sipe width direction as viewed in cross section perpendicular to a sipe length direction, the first stereoscopic sipe having a fixed sipe width over a sipe depth direction. The second stereoscopic sipe has large width portions having a sipe width wider than a sipe width of the second stereoscopic sipe on a surface of the tread rubber in the inside of the tread rubber. Rubber hardness of the tread rubber in the vehicle outer side region is larger than rubber hardness of the tread rubber in the vehicle inner side region. Accordingly, it is possible to enhance dry steering stability performance while suppressing lowering of ice braking performance.

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 that is a rotation of the tire in a counterclockwise direction when the tire is mounted on a vehicle in a first orientation and viewed from the first side. The second side defines a second forward rotation direction of the tire that is a rotation of the tire in the counterclockwise direction when the tire is mounted on the vehicle in a second orientation opposite the first orientation and viewed from the first side. The circumferential tread includes a plurality of tread elements. At least one of the tread elements includes a sipe arrangement that 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. The sipe arrangement causes the tire to exhibit a second tire performance that is different from the first tire performance when the tire is mounted on the vehicle in the second orientation and rotated in the second forward rotation direction. The method further 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.

Provided is a pneumatic tire 1 on which mediate land portions 23a, 23a are formed. Sipes 24 are formed in the mediate land portions 23a, 23b respectively. The mediate land portion 23a disposed inside in a vehicle width direction in a state where the pneumatic tire 1 is mounted on a vehicle has larger sipe density and projects more outwardly in a tire radial direction than the mediate land portion 23b disposed outside in the vehicle width direction in a state where the pneumatic tire 1 is mounted on the vehicle.