The present invention relates to self-supporting tyres for vehicle wheels having sidewall reinforcement inserts (113) with reduced rigidity. These tyres have a good mileage in flat running conditions, greater comfort and significantly reduced rolling resistance compared to known self-supporting tyres, with higher modulus sidewall reinforcement inserts.

The present invention relates to a self-supporting tire for vehicle wheels comprising a carcass structure comprising at least one carcass ply having a plurality of hybrid reinforcing cords (10) each comprising at least two strands (20) twisted to each other with a predetermined stranding pitch (P), wherein each of said at least two strands (20) comprises at least one monofilament textile thread (21) at least partially embedded in the filaments (22a) of at least one multifilament textile yarn (22) and a pair of sidewall reinforcement inserts (113), where at least one of said sidewall reinforcement inserts comprises a vulcanised elastomeric compound which has a dynamic shear modulus value G equal to or less than 1.25 MPa measured at 70° C., 10 Hz, 9% deformation according to the RPA method reported in the present description.

In a pneumatic tire including an annular tread portion extending in a tire circumferential direction, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on an inner side of the sidewall portions in a tire radial direction, a load support body is disposed extending along the tire circumferential direction on an inner side of each of the sidewall portions, and the load support body is removably mounted to an inner surface of the sidewall portion via a mechanical engagement device.

Provided is a run flat tire comprising a side reinforcing layer on a sidewall part, wherein a rubber composition of the side reinforcing layer has a complex elastic modulus at 100° C. (E*.sub.100) of 5.0 to 17 MPa and a loss tangent at 60° C. (60° C. tan δ) of 0.020 to 0.100 MPa, and wherein, where a tire cross-sectional width is defined as Wt (mm) and a tire outer diameter is defined as Dt (mm), Wt and Dt satisfy any of the following inequality (1), (2), and (3):

Wt<225 and Dt≥59.078×Wt{circumflex over ( )}0.460  (1)

225≤Wt<235 and Dt≥59.078×Wt{circumflex over ( )}0.620−967.673  (2)

235≤Wt and Dt≥Wt{circumflex over ( )}0.6+750  (3)

A tire includes a tread portion. The tread portion has a main groove extending continuously in a tire circumferential direction, and a land portion adjacent to the main groove. The land portion has lateral grooves extending from the main groove in a tire axial direction. Each of the lateral grooves has a first portion communicating with the main groove, and a second portion connected to the first portion. The first portion has a larger groove width than the second portion and has a smaller groove depth than the second portion.

A run flat tire having improved run flat durability is provided. The run flat tire has a side wall part reinforced by a side reinforcing rubber part, and the side reinforcing rubber part is formed by a rubber composition which comprises 100 parts by mass of a diene rubber containing natural rubber and polybutadiene rubber, and from 0.1 to 4.0 parts by mass of a mercaptobenzimidazole compound.

The run-flat tire of this disclosure includes a tread portion, a pair of sidewall portions continuous, bead portions, side reinforcing rubbers with crescent-like cross section, and a carcass, wherein: when the tire is mounted to a rim, and an internal pressure of 250 kPa or more is applied, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; and in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD≧2.135×SW+282.3 (mm); and when H1 is a tire radial maximum length of the side reinforcing rubber in a tire widthwise cross section in a reference state, a relation expression 10 (mm)≦(SW/OD)×H1≦20 (mm) is satisfied.

The run-flat tire of this disclosure includes a tread portion, a pair of sidewall portions, bead portions, side reinforcing rubbers with crescent-like cross section, and a carcass formed of plies of radially arranged cords, wherein: when the tire is mounted to a rim, and an internal pressure of 250 kPa or more is applied to the tire, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD≧2.135×SW+282.3 (mm); and the relation expression 0.5≦WG/WB≦0.8 is satisfied.

The run-flat tire of this disclosure includes a tread portion, a pair of sidewall portions, bead portions, side reinforcing rubbers with crescent-like cross section, a carcass formed of plies of radially arranged cords, wherein: when the tire is mounted to a rim, and an internal pressure of 250 kPa or more is applied to the tire, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD≧2.135×SW+282.3 (mm); the bead portions have bead cores, and further have bead fillers; and the relation expression 1.8≦H1/H2≦3.5 is satisfied.

A run-flat tire includes a side reinforcing rubber layer, a first bead filler on an inner side of a carcass turned-up portion in a width direction, and a second bead filler on an outer side of the carcass turned-up portion in the width direction. A first bead filler height is 30% or less of a tire cross-sectional height SH. A second bead filler height is 50% or greater of the height SH. A cross-sectional area of the second bead filler is from 150% to 400% of a cross-sectional area of the first bead filler. A relationship (0.16×SH×LI−1100)≤S.sub.ALL≤(0.16×SH×LI−800) is satisfied, where S.sub.ALL represents a sum of cross-sectional areas of the side reinforcing rubber layer and the first and second bead fillers, and LI represents a load index.