A pneumatic tire includes a tread portion including an inboard tread region between a tire equator and an inboard tread edge, and an outboard tread region between the tire equator and an outboard tread edge. The inboard tread region is provided with a first main groove extending and a second main groove each extending continuously in the tire circumferential direction. The outboard tread region is provided with a plurality of recesses that are not in communication with other grooves. The recesses include a plurality of deep bottom recesses having depths equal to or more than 5 mm. A total of opening areas of the deep bottom recesses on a ground contact surface of the tread portion is equal to or less than 5% of a surface area of the outboard tread region that is obtained by filling up all grooves and recesses provided thereon.

The device for monitoring the wear of a tread during running comprises at least one internal cavity intended to form a void opening on to a tread surface after predefined partial wearing of the tread, this tread comprising a wear limit corresponding to a maximum thickness of wearable material, this device comprising a measurement well opening on to the tread surface, this measurement well having a bottom formed of a first part and of a second part which are offset from one another in the depth, these two parts of the bottom being situated at different distances with respect to the tread surface when new.

In a tire having composite grooves provided on a shoulder land portion, dry performance and wet performance are improved. The tire includes a tread portion 2. The tread portion 2 includes a first shoulder land portion 13. The first shoulder land portion 13 has shoulder lateral grooves 15 and shoulder composite grooves 20. The shoulder lateral grooves 15 and the shoulder composite grooves 20 are each curved so as to be convex in a tire circumferential direction. Each shoulder composite groove 20 includes, in a cross section thereof, a sipe element 21 having a width not greater than 1.5 mm and extending from a tread surface of the first shoulder land portion 13 in a tire radial direction, and a groove element 22 connected to an inner side in the tire radial direction of the sipe element 21 and having a width greater than 1.5 mm.

In a tire having a composite groove provided on a shoulder land portion, the durability of the shoulder land portion is improved. The tire includes a tread portion. The tread portion includes a first shoulder land portion including a first tread edge. The first shoulder land portion has a shoulder composite groove, and a recess formed on a buttress surface. The recess includes an opening edge on the buttress surface, a bottom surface along the buttress surface, and an inner wall surface connecting the opening edge to the bottom surface. The shoulder composite groove includes, in a transverse cross section thereof, a sipe element having a width not greater than 1.5 mm and extending in a tire radial direction, and a groove element connected to an inner side in the tire radial direction of the sipe element and having a width greater than 1.5 mm. The groove element is open at the bottom surface of the recess.

A pneumatic tire has a tread having adjacent rib-shaped land portions (4) with circumferential grooves (3) therebetween. Annular elongate projection portions (5, 5) project toward each other from adjacent rib-shaped land portions (4). The elongate projection portions (5, 5) confronting each other are disposed with a spacing therebetween such that their mutually confronting tip surfaces (5s, 5s) make contact with each other due to elastic deformation of the rib-shaped land portions (4, 4) at the time of grounding of the tire. An inside groove space (6) is formed on a radially inner side of the confronting elongate projection portions (5, 5) and an outside groove space (7) is formed on a radially outer side of the elongate projection portions (5, 5). The tip surfaces (5s) of the elongate projection portions (5) are formed with a plurality of communication recesses (9) providing communication between the inside and outside groove spaces (6, 7). The communication recesses (9) are formed at intervals in a tread circumferential direction. It is thus possible to enhance rigidity of the rib-shaped land portions over the whole tread at the time of grounding of the tire, thereby to suppress elastic deformation of the rib-shaped land portions and to reduce rolling resistance, while securing a draining property attributable to the circumferential grooves.

Embodiments of the disclosure include a tire tread having tread blocks (24) each defined by a pair of lateral grooves (20) each being asymmetric whereby a first portion (26) of a trailing side (TS24) the tread block is inclined and extends to a peak (28), and whereby a recess (38) projects into tread block below the first portion. Each tread block also includes a sipe (22) extending into the tread thickness from the outer, ground-engaging side of the tread, where the sipe is generally inclined relative to the direction of the tread thickness, such that as the sipe extends into the tread thickness from the outer, ground-engaging side, the sipe extends towards the trailing side (TS24) of the corresponding tread block, the sipe including a groove (40) arranged along the sipe within the tread thickness and spaced below the outer, ground-engaging side of the tread. The groove being asymmetric relative to a centerline (CL22) of the sipe.

Tread for heavy-duty vehicle tire, having tread surface in the new state, having a first volume of cavities opening onto the tread surface, a second volume of cavities formed entirely under the tread surface and having at least one channel of height Hc delimited by two main walls spaced apart from one another by a width Lc and connected together by a lower part and by an upper part, this channel intended to form, after partial wear corresponding to a thickness Lu, an additional groove, such that each channel has a plurality of extensions forming cavities extending between this channel and the tread surface over a height He at least equal to 20% and at most equal to 75% of the thickness Lu, each extension opening at least into the upper part of the channel through an opening having a cross-sectional area Sa at least equal to 0.8*(Hc*Lc).

Tire tread (1) comprising a tread surface intended to come into contact with a road surface, this tread (1) having main groove (2) that, when new, opens onto tread surface (10). Main groove (2) has a maximum depth (P), and comprises a plurality of first groove portions (21) and a plurality of second groove portions (22) arranged alternately such that a first portion (21) is followed by a second portion (22). Each first groove portion (21) has a width that decreases with wear, each first groove portion (21) having a maximum width (L1) measured on the tread surface when new and a maximum width (L1) at the depth (P), the maximum width (L1) at the depth (P) being less than the maximum width (L1). Each second groove portion (22) has a width that increases with wear, each second groove portion (22) having a maximum width (L2) measured on the tread surface when new (10) and a maximum width (L2) at the depth (P), the maximum width (L2) being less than the maximum width (L2). The first and second groove portions are arranged so as to form a void passage (3) between the volumes delimited by the first and second groove portions over the whole length of the groove (2), this passage (3) having a cross section, the maximum width of which is located between 30% and 85% of the depth (P) of the groove (2).

The tread has four grooves that delimit a central, intermediate and edge regions. Each intermediate region is divided into elongated raised elements that delimit oblique grooves which open into the circumferential grooves and are inclined at an average angle of between 30 and 60 degrees relative to the circumferential direction. The raised elements have an average circumferential length of between 50 and 70 mm. The depth of the oblique grooves is at least 30% of the depth of the circumferential grooves. Each raised element has a plurality of sipes that open into the oblique grooves. Each raised element also has an internal and oblique cut that has a total depth at least equal to 75% of the thickness PMU to be worn away. The oblique cut has a wide part and a part that forms a sipe that extends by a channel that forms a new groove after wear.

The tread has main grooves that delimit a central region of a width comprised between 15 and 25% of a total width W and that define the wearable thickness of the tread. The tread also has lateral regions on each side of the central region, and the lateral regions are divided into raised elements. The elongate elements are delimited by oblique secondary grooves which are inclined by a mean angle of between 35 degrees and 55 degrees with respect to the circumferential direction and have a depth P5 which is between 30% and 60% of the depth P. Each elongate raised element has an oblique cut which divides the element into two elongate element halves, and each oblique cut is formed by a sipe extended by an internal canal. The internal canal forms a new groove once the tread is partially worn before the oblique secondary grooves completely disappear.