Each of at least two layers of a carcass reinforcement has a breaking force per unit width higher than 2250 daN/dm. The minimum strength per unit width, measured for an elongation of less than 10%, of a second layer of carcass reinforcement is strictly greater than a value equal to 20% of the minimum strength per unit width, measured for an elongation of less than 10%, of a first layer of carcass reinforcement. The reinforcing elements of the two layers of carcass reinforcement have a thread count of less than 750 tex. The elongation of the reinforcing elements of the second layer of carcass reinforcement is greater than 4% under a force of 20 daN, and the secant elastic modulus values under tension at 10% elongation, Mt, Mj, satisfy the relationship Mt/Mj1.

A tire includes tread having at least one ring-shaped steel belt extending in a circumferential direction of the tire, and a pair of beads having bead filler extending to an outer side of a tire-radial direction of the bead core, in which an electronic component is embedded in a region between a tire-radial direction outside end of the bead filler and a tire-width direction outside end of the steel belt.

A ply of a carcass of a pneumatic radial tire includes a turn-up ply and a down ply. The turn-up ply includes: a main body portion disposed between a pair of bead cores; turn-up portions around the bead cores from an inside toward an outside in a tire width direction. The down ply extends up to an inside in a radial direction of the bead cores so as to cover the turn-up ply including the turn-up portions from an outside. A curvature is formed at either one of a down ply predetermined portion of the down ply, which covers a turn-up end portion of the turn-up portion of the down ply from an outside in the tire width direction, and a turn-up ply portion that covers the turn-up end portion of the turn-up portion in the main body portion of the turn-up ply from inside in the tire width direction.

A pneumatic tire includes one carcass including a folded up portion and a reinforcing layer between the folded up portion and a bead filler. The folded up portion has an end portion in a region inward of a belt layer in a radial direction and inward of the belt layer in a lateral direction. The bead filler has an outer end portion distanced from a bead heel portion from 20% or more to 40% or less of a tire cross-sectional height. The reinforcing layer has an outer end portion outward of the outer end portion of the bead filler in the radial direction and inward in the radial direction with respect to a position of a tire maximum width position in the radial direction. A sidewall portion is formed of a side rubber having tan at 60 C. of from 0.04 or more to 0.10 or less.

In a tire 2, a length from a center in an axial direction of a boundary between a core 30 and an apex 32 of each bead 10 to an outer end PA of the apex 32 is not less than 10 mm and not greater than 15 mm In a state where the tire 2 is mounted on a normal rim and an internal pressure of the tire 2 is adjusted to a normal internal pressure, a shape of a main body portion 36, of a carcass ply 34, which is located in a zone from a boundary portion between a tread 4 and each sidewall 6 to the outer end PA of each apex 32 is represented by a single circular arc, and a diameter of the circular arc is not less than 75% and not greater than 90% of a cross-sectional height of a carcass 14.

When a tire that is mounted on a specified rim, inflated to an internal pressure of 50 kPa, and placed in a no-load state is viewed as a cross-section from the tire meridian direction, a position of 1.30Hf on an outer surface of a sidewall portion, taking a rim flange height (Hf) of the specified rim as a reference, is defined as a point (P), a foot of a normal line (L) drawn from the point (P) to a carcass line of a main body portion (131) of a carcass layer (13) is defined as a point (M), and a point of intersection of the normal line (L) and a carcass line of a folded back portion (132) of the carcass layer (13) is defined as a point (T). At this time, a distance (a) mm from the point (M) to the point (T), a distance (b) mm from the point (T) to the point (P), and a specified load (x) kN have relationships such that a=0.019x+13.3 and b=0.052x+21.6, with a tolerance of not less than 0% and not more than 20%.

A tire includes a pair of beads; a carcass that is extended on and between the beads on both sides; and a pair of strips that extend almost outward from the beads along the carcass in the radial direction. The beads include cores, first apexes, and second apexes. The carcass includes a carcass ply, and the carcass ply includes a main portion and turned-up portions. The turned-up portions are disposed between the first apexes and the second apexes. The turned-up portions contact with the main portion in portions radially outward of outer ends of the first apexes. A position of an outer end of each strip is equal, in the radial direction, to a position Pb at which the maximum width is obtained, or the outer end of each strip is disposed radially inward of the position Pb at which the maximum width is obtained.

A tire can include a pair of beads, a carcass, a pair of protective rubber layers, and a pair of reinforcing rubber layers. A carcass ply of the carcass can include a ply body and a pair of turned-up portions. Each reinforcing rubber layer can be between the turned-up portion and the protective rubber layer. An outer end of an apex of each bead can be between an outer end and an inner end of the reinforcing rubber layer in a radial direction. A thickness of the protective rubber layer in a zone from a rim contact end to the outer end of the reinforcing rubber layer can be small at a center portion in the radial direction of the reinforcing rubber layer and can be large at another portion.

A pneumatic tire is provided. A tire outer surface contour line from a sidewall portion to a bead portion has a center on a tire axial line passing a tire maximum width position and has a contour arc, which passes the tire maximum width position and is connected to a bead heel portion of the bead portion; and a contour straight line, which has one end connected to the contour arc and the other end connected to the bead heel portion. A connection part of the contour straight line and the bead heel portion is set such that a height H1 in a tire radial direction from a bead toe to the tire maximum width position and a height H5 in the tire radial direction from the bead toe fall with a range of (0.3H1)H5(0.25H1). A connection part of the contour arc and the contour straight line is set such that a height H2 in the tire radial direction from the bead toe falls within a range of (0.9H1)H2(0.75H1).

The bead portion of the pneumatic tire includes a bead structure having a bead core composed of a bead cord, and an annular plate which extends to the tire circumferential direction and is formed of a resin material. The annular plate has a planar first annular ring portion extending to the tire circumferential direction and a second annular ring portion positioned outside the tire radial direction of the first annular portion and extending to the tire circumferential direction, the first annular portion is provided along the bead structure, and the second annular portion is further inclined to the outside in tire width direction of the first annular portion.