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).

A pneumatic vehicle tire, in particular a commercial vehicle tire, includes a tread which has a profile and has at least one circumferential groove (1) which is encircling in the circumferential direction, is embodied to a profile depth (P.sub.T) and in the cross section, starting at the tread external face, is composed of three adjoining groove portions, one outer groove portion (2) that expands in a funnel-shaped manner toward the outside, one 1 mm to 3 mm wide contracted groove portion, and one inner groove portion (4) which lies radially inward, is expanded in relation to the contracted groove portion (3) and has the largest cross-sectional face of all portions, and which is delimited by two cover flanks (4a), lateral groove flanks (4′b, 4″b) that adjoin said cover flanks (4a), and a groove base (4c).

A pneumatic tire includes rib-shaped land parts adjacent to each other with a circumferential groove therebetween, and raised-row-shaped projections projecting toward each other from both mutually opposed side wall surfaces of the adjacent rib-shaped land parts are provided to extend in the tread circumferential direction. As compared to a raised-row-shaped projection in an outermost-side circumferential groove located on a tire width direction outermost side, a raised-row-shaped projection in an inner adjacent circumferential groove located on tire width direction inner side of and adjacent to the outermost-side circumferential groove is formed at a shallower position near a tread surface between the tread surface and the groove bottom. As a result, it is possible to obtain suitable drainage properties according to the tire width direction positions of the circumferential grooves, while restraining an increase in rolling resistance, and to realize improved wet grip performance owing to an enlarged grounding area.

A lateral groove provided in a tread portion has: an opening formed in a tread surface; a minimum portion having the smallest groove width, positioned radially inside the opening; and a maximum portion having the largest groove width, positioned radially inside the minimum portion. The width of the opening increases toward the outside in the tire axial direction.

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 circumferential main groove has a stabilizing structure for increasing tread stiffness. The stabilizing structure is axially offset a predetermined amount from a centerline of the fourth circumferential main groove. The fourth circumferential main groove has an angled axially inner sidewall, an angled axially outer sidewall, and a curved base surface. The stabilizing structure extends radially inward from the curved base surface of the fourth circumferential main groove.

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.

A tire includes a circumferential narrow main groove extending in a tire circumferential direction provided in a tread portion. The circumferential narrow main groove includes a narrow groove portion having a groove width W1 in a range of 1.0 mm≤W1≤4.0 mm in a region where a groove depth from a road contact surface of the tread portion is less than 30%, and a widened portion having a maximum groove width W2 more widened than the groove width W1 in a region where the groove depth is 30% or more.

A circumferential narrow main groove extending in a circumferential direction in a tread of a pneumatic tire. The circumferential narrow main groove includes a narrow portion opening to a road contact surface of the tread and a widened portion having a wider groove width than the narrow portion. The widened portion is at a groove bottom. A groove width ratio (W2/W1) of a maximum groove width W2 of the widened portion to a groove width W1 of the narrow groove portion is in a range 1.5≤(W2/W1)≤4.0, and a cross-sectional area ratio (A2/A1) of a groove bottom-side cross-sectional area A2 to a groove opening-side cross-sectional area A1 in a meridian cross-section is within a range 1.2<(A2/A1)<4.0 when the circumferential narrow main groove is divided into two parts at 50% of a maximum groove depth of the circumferential narrow main groove. The cross-sectional area ratio changes along the circumferential direction.

A tread for a heavy goods vehicle tire, the tread having a surface when new suitable for coming into contact with a road surface, this tread having a plurality of optimized incisions opening onto its tread surface when new, each incision made of at least two narrow portions and wide portions, each narrow portion surrounded by wide portions, the sum of the areas of narrow portions representing at least 40% of the total surface of the incision (and the width being less than 0.4 mm, each portion having a width at least equal to 0.4 mm, this tread being such that for each optimized incision each of the wide portions extending between two narrow portions includes at least one section inclined in a plane parallel to the mid-plane of the optimized incision, and forming an angle at least 15 degrees with the direction of the tread thickness.

A tire having a tread portion provided with a first circumferential groove and a second circumferential groove each extending in the tire circumferential direction, and lateral grooves connecting between the first circumferential groove and the second circumferential groove. The first circumferential groove extends zigzag and comprises a radially outer first portion having the smallest width and a radially inner second portion having a width larger than that of the first portion.