A pneumatic tire has a non-stretchable tread (30) flanked by two shoulder regions (34), and two non-stretchable bead regions (36) for mounting the tire to a wheel, each bead region being connected via a sidewall to the corresponding bead region. Each sidewall has a first portion (38) extending inwardly relative to a width of the tire from one of the bead regions (36) to a deflection region (40), and a second portion (42) extending outwardly relative to the width of the tire from the deflection region (40) to a corresponding one of the shoulder regions (34). A non-stretchable girth-limiting configuration (44, 46, 56) and a radial reinforcing structure (48, 50, 52) are associated with the first portion (38) of each of the sidewalls, thereby limiting radial flexing of first portion (38) and maintaining an annular concavity between the bead region (36) and the shoulder region (34).

A ground contact region of the tread portion of a studdable tire includes a center region located over a range corresponding to a length of 5 to 25% of a ground contact width from a tire centerline on each of both sides of the tire centerline in a tire width direction; and two shoulder regions located on both sides of the center region in the tire width direction. In each of the center region and the shoulder regions, a plurality of the stud pin installation holes are disposed along each of four or more pin arrangement lines extending in a tire circumferential direction. An average value of adjacent intervals between the pin arrangement lines in the center region is larger than an average value of adjacent intervals between the pin arrangement lines in each of the shoulder regions.

A tire comprises a tread provided with two edges (25A, 25B) and with a center (C) dividing it into two parts of equal width with sets of blocks (21A, 21B). Each set of blocks (21A, 21B) comprises three zones: at the edge (211), at the center (213) and intermediate (212). Each set of blocks (21A, 21B) comprises a set of chamfers (26A, 26B, 26C) which extends over at least the edge zone (211) and the central zone (213) of the set of blocks (21A, 21B). The width LC1 of the set of chamfers (26A, 26B, 26C) over the edge zone (211) is different from the width LC2 of the set of chamfers (26A, 26B, 26C) over the intermediate zone (212), the widths LC1 and LC2 being comprised between 0.5 mm and 2.5 mm.

A tire comprises a directional tread provided with two edges (25A, 25B) and with a center (C) dividing it into two parts of substantially equal width. The tread comprises, on one of these two parts, blocks (21A, 21B) succeeding one another in a circumferential direction. Each block (21A, 21B) has a leading-edge face (26) and a trailing-edge face (27). The tire comprises, for at least one set of blocks (21A, 21B), at least one set of cavities (29) extending over the trailing-edge face (27) of the set of blocks (21A, 21B). The tread has a bottom surface (24) radially on the inside of the tread, the set of blocks (21A) having a height H, wherein the set of cavities (29) is between the bottom surface (24) of the tread and half of the height H.

Tire with a tread provided with two edges (25A, 25B) and with a centre (C) dividing it into two parts of equal width with sets of blocks (21A, 21B). Each set of blocks (21A, 21B) has three zones: at the edge (211), at the centre (213) and intermediate (212). Each set of blocks (21A, 21B) has a set of chamfers (26A, 26B, 26C) which extends over at least the edge zone (211) and the central zone (213) of the set of blocks (21A, 21B). The width LC2 of the set of chamfers (26A, 26B, 26C) over the intermediate zone (212) is different from the width LC3 of the set of chamfers (26A, 26B, 26C) over the central zone (213), said widths LC2 and LC3 being comprised between 0.5 mm and 2.5 mm.

A tire comprises a directional tread of width (W), having a total volume VT, comprising voids (221, 211, 212) defining a voids volume VE. There is defined a volumetric voids ratio TEV=VE/VT, part of the voids (211) delimits blocks (21A, 21B) which are organized into patterns (26) of blocks of pitch P succeeding one another in the circumferential direction (X). Part of the voids forms sipes (211, 212) in one of the patterns. The sipes density SD corresponds to the ratio of a sum of the projected lengths (lpyi) of the sipes in an axial direction to the product of the pitch P of the pattern times the width (W), all multiplied by 1000. SD in any pattern of pitch P is comprised between 10 mm.sup.−1 and 70 mm.sup.−1. TEV is at least equal to 0.29 and at most equal to 0.35.

A tire comprises a directional tread which forms a contact patch AC during running. The tread comprises a plurality of blocks (21A, 21B) which form a contact surface SC. The surface voids ratio is defined by TES=(AC−SC)/AC. The blocks (21A, 21B) are organized into patterns (26) of blocks of pitch P which succeed one another in the circumferential direction (X), in a pattern comprising at least one sipe. The sipes density is defined by the formula

[00001]$\mathrm{SD}=\frac{{.Math.}_{i=1}^n\mathrm{lpyi}}{P*W}*1000,$

where n is the number of sipes, lpyi is the projected distance of the sipe i in the axial direction (Y), and W is the width of the tread. Simultaneously, SD is at least equal to 10 mm-1 and at most equal to 70 mm-1, and TES is at least equal to 0.40 and at most equal to 0.70.

A tire comprises a tread of width (W), having a total volume VT, comprising voids (221, 211, 212) defining a voids volume VE. There is defined TEV=VE/VT. Voids (211) delimit blocks (21A, 21B) organized into patterns (26) of pitch P succeeding one another in the circumferential direction (X). Part of the voids forms sipes (211, 212) in one of the patterns. SD corresponds to the ratio of a sum of the projected lengths (lpyi) of the sipes in an axial direction (Y) to the product P times W, multiplied by 1000. The tread forms a contact patch AC and blocks (21A, 21B) form a contact surface SC: TES=(AC−SC)/AC. For the tread when new, SD in any pattern of pitch P is comprised between 10 mm.sup.−1 and 70 mm.sup.−1, and TES/TEV is comprised between 1.5 and 1.9.

A non-pneumatic tire (10) comprising a tread band having a ground engaging surface, a first reinforcement layer (250) comprised of at least one reinforcement (251) oriented in the tire's circumferential direction, a second reinforcement layer (254), located radially outward from said first reinforcement layer (250), said second reinforcement layer (254) comprised of a plurality of reinforcements oriented at an angle in a first direction to said tire's circumferential direction, a third reinforcement layer (258), located radially outward from said second reinforcement layer (254), said third reinforcement layer (258) comprised of a plurality of reinforcements oriented at an angle in a second direction to said tire's circumferential direction and a fourth reinforcement layer (262), located radially outward from said third reinforcement layer (258), comprised of at least one reinforcement oriented in the tire's circumferential direction.

A tire (10, 10′) for rotation about an axis of rotation (12) has a first wall portion (14) having a partially conical form, and a second wall portion (16) integrally formed and interconnected with the first wall portion at a transition region (18) so as to define an annular recess. A closure-limiting configuration includes a number of tubular reinforcing elements (20) arrayed around the annular recess. Each tubular reinforcing element has a wall with a closed cross-section. The tubular reinforcing elements (20) are spaced around the annular recess such that deformation of a compressed region of the tire under a load causes a change in shape of the tubular reinforcing elements in the compressed region.