A layer of cellular material forms a running layer (14A) of a tread (14) in which tread pattern elements (20, 22, 26) are made. In order to form the cellular material, an uncured blank is provided with a mass of material comprising p,p-oxybis(benzenesulphonyl hydrazide) that forms a pore-forming agent. The uncured blank is placed in a vulcanization mold (28) comprising molding elements (30, 32, 34). At least 95% of the molding elements (30, 32, 34) each satisfy the following two conditions: a) the molding element (30, 32, 34) is separated from at least one other molding element (30, 32, 34) by a distance, expressed in millimeters, of less than or equal to
DM=6.85+0.0065T3, T, greater than or equal to 3 phr, being the amount of p,p-oxybis(benzenesulphonyl hydrazide) in the mass of material intended to form the cellular material, b) the molding element (30, 32, 34) is intended to form a tread pattern element (20, 22, 26) having a depth at least equal to 80% of the thickness of the running layer (14A).

A tire for two-wheeled motorized vehicle having tread connected by sidewalls to beads, each having circumferential reinforcing bead wire, each contacting a rim on which the tire is mounted, the tire has an indicator system of a plurality of cavities formed on tread surface, each cavity having maximum depth less than 1 mm and average width of less than 3 mm, and arranged in a plurality of circumferential sets of cavities) representing different camber angles of the tire, each circumferential set having plurality of cavities arranged in circular arc, wherein two adjacent cavities are spaced along circular arc by circumferential pitch (Pc) between 1 mm and 10 mm, the circumferential sets arranged in specific radial pattern defined by a radial pitch (Pr) corresponding to spacing in radial direction between circular arcs of two adjacent circumferential sets of cavities, the radial pitch (Pr) being between 1 mm and 10 mm.

Tire for a heavy goods vehicle comprising a tread of total thickness E and total volume V, having a tread surface intended to come into contact with a roadway, at least one cavity or groove that is continuous in a main direction, and delimited by side walls connected by a bottom, a cross section, the points furthest towards the inside of the bottom of each cavity defining a bottom line, wherein each cavity or groove comprises a plurality of open sections open onto the tread surface in the new state and a plurality of closed sections, connected to the open sections being arranged in alternation, each closed section being spaced away from the tread surface by a bridge of rubber, wherein the points on the bottom line of said cavity or groove lie at distances between a minimum distance Dm and a maximum distance DM with respect to the tread surface, the bottom line of each cavity or groove following a wavy geometry of positive amplitude equal to the difference (DMDm).

A two-wheel vehicle tire has a tread portion. The tread portion includes a plurality of grooves. The grooves include crown grooves arranged on a tire equator, middle grooves, and shoulder grooves. Each of the crown grooves is bent in a V-shape so as to be convex to one side in a tire circumferential direction. Each of the grooves has the shortest distance from 5% to 30% of a tread development half width between another one of the grooves immediately adjacent to the each of the grooves.