In a side reinforcing type tire 2, when a cross-sectional height of the tire 2 is denoted by L, a height in a radial direction from a bead base line to an outer edge of a core 34 is denoted by HC, a point on a turned-up portion 42 of a carcass ply 38 at which point a height in the radial direction from the bead base line is 0.35 times of the height L is denoted by P1, and a point on the turned-up portion 42 at which point the height in the radial direction from the bead base line is equal to the height HC is denoted by P2, the turned-up portion 42 has, between the point P1 and the point P2, a shape that is a curved line projecting inward in an axial direction, a straight line, or a combination thereof.

In a pneumatic tire 2 according to the present invention, in the vicinity of a bead 10 portion, a main portion 42 of a carcass ply 40 is passed through the vicinity of a neutral surface. A tensile force and a compressive force applied to the main portion 42 are small. In the tire 2, occurrence of pinch cut is suppressed. In addition, this structure alleviates a force applied to the main portion 42 even during run-flat running. In the tire 2, damage is less likely to occur even during run-flat running for a long period of time. The tire 2 has excellent run-flat durability. Furthermore, in the tire 2, an increase in the vertical stiffness constant or weight thereof is suppressed.

A run-flat tire comprises a tread portion, sidewall portions, bead portions, and a carcass ply extending between the bead portions. The sidewall portions are each provided therein with a sidewall reinforcing rubber layer having a crescent-shaped cross sectional shape and disposed on the axially inside of the carcass ply. The sidewall portions are each provided in the axially outer surface thereof with a rim protector which projects radially outward most on the radially outside of the radially inner edge of the sidewall reinforcing rubber layer. The bead portions are each provided therein with an axially inside core and an axially outside core between which each radially inner edge portion of the carcass ply is secured. When measured along a normal line drawn normally to the carcass ply from an apex of the rim protector, the thickness of the sidewall reinforcing rubber layer is in a range of from 29% to 35% of the thickness of the tire.

A run-flat radial tire having a tire cross-section height of 115 mm or greater including: a carcass spanning between a pair of bead portions; a vehicle mounting direction outer side side-reinforcing rubber layer that is provided to a tire side portion at a vehicle mounting direction outer side and that extends in a tire radial direction along an inner face of the carcass; and a vehicle mounting direction inner side side-reinforcing rubber layer that is provided to a tire side portion at a vehicle mounting direction inner side and that extends in the tire radial direction along an inner face of the carcass, a tire radial direction outer side end portion of the vehicle mounting direction inner side side-reinforcing rubber layer being closer to a tire equatorial plane than a tire radial direction outer side end portion of the vehicle mounting direction outer side side-reinforcing rubber layer.

A run-flat radial tire is provided with a side reinforcement rubber layer that extends in the tire radial direction along an inner face of a carcass and an angled belt layer that is provided at the tire radial direction outer side of the carcass. An overlap length L between a maximum width angled belt layer and the side reinforcement rubber layer satisfies the relationship L>0.14 SH with a tire section height SH. A thickness GD of the side reinforcement rubber layer at a position that is 14% of the tire section height to the tire axial direction inner side from a tire axial direction end portion of the maximum width angled belt layer and a thickness GA of the side reinforcement rubber layer at a maximum width position of the carcass satisfy the relationship GD/GA0.3.

A pneumatic tire comprises a carcass formed of a carcass ply extending between a pair of bead portions in a toroidal shape, and a bead core disposed in a respective one of the bead portions, the bead core comprising an axially inner core and an axially outer core respectively disposed on an axially inner side and the axially outer side of the carcass ply. The bead portion comprises an inner bead apex rubber extending radially outward from the inner core, and an outer bead apex rubber extending radially outward from the outer core. An outer apex height Ho from a bead base line to a outer end of the outer bead apex rubber is in a range of from 120% to 150% of an inner apex height Hi from the bead base line to the outer end of the inner bead apex rubber.

A run-flat radial tire has a tire section height SH equal to or greater than 115 mm and is equipped with a side-reinforcing rubber layer extending along an inner surface of a carcass from one tire side portion to another tire side portion wherein a tire equatorial plane CL is sandwiched in between the one tire side portion and the another tire side portion, wherein a thickness GE of the side-reinforcing rubber layer at the position of the tire equatorial plane and a thickness GA of the side-reinforcing rubber layer at positions where the carcass reaches its maximum width satisfy the relational expression GE0.6GA.

Provided is a run-flat tire. A first bead filler is disposed on an outer circumferential side of a bead core, a second bead filler is disposed on an outer side in a tire width direction of a turned up portion of the carcass layer along the turned up portion of the carcass layer, and a thickness G on a first reference line of a side reinforcing layer, a thickness G1 on a second reference line of the side reinforcing layer, and a thickness G2 on a third reference line of the side reinforcing layer satisfy the relationships of 0.8GG11.0G and 0.5GG20.7G.

The tire maximum width in the reference condition is the center value or more and the upper limit or less of the tire maximum width specified in the standard, and the tire maximum width position in the reference condition is located at the position, with a distance of more than 50% of the tire cross-sectional height, outward in the tire radial direction from the bead baseline.

A tire (10) comprises a crown block (12), two beads (32), and two sidewalls (30) connecting each bead (32) to the crown block (12). The crown block (12) comprises a crown reinforcement (16) comprising a corrugated crown layer (24, 26, 28) comprising corrugations. The tire (10) comprises a sidewall insert (90) comprising a rigid elastomeric composition (92, 93, 94) of which the radially exterior end (96) is arranged: radially to the outside of the equator (E) of the tyre, and axially to the inside of the axial end (241, 242) of the radially innermost crown layer (24) of the crown reinforcement (16) and at an axial distance ENG20 mm from the axial end (242).