A tire constructed with a plurality of reinforcement belts is provided. At least one of the reinforcement belts extends along the axial width of the tire summit and is constructed according to an equilibrium curve that is flat throughout the summit. The reinforcement belts include cable reinforcements that are substantially parallel to the equatorial plane. Substantial reductions in the tension experienced by the cables can be achieved to provide, as a result, improvements in e.g., tread wear.

In a pneumatic tire 2, a contour of an outer surface of each side portion includes a first segment that is a straight line or a circular arc, and a second segment that is a straight line or a circular arc and that is connected to an end of the first segment. The contour of the outer surface of the side portion bends outward with a connection point of the first segment and the second segment as a bending point. The first segment and the second segment are preferably straight lines.

A pneumatic tire includes a reinforcing rubber layer disposed in the sidewall portions and having a crescent-like meridian cross-section; wherein when the tire is assembled on a regular rim and in an unloaded state with an internal pressure of 0 kPa, a radius of curvature (RP) is larger than a radius of curvature (RO), an arc of the radius of curvature (RP) joining an intersection (Pa) of a carcass layer and a straight line (La), an intersection (Pb) of the carcass layer and a straight line (Lb), and an intersection (Pc) of the carcass layer and a straight line (Lc), and an arc of the radius of curvature (RO) joining an intersection (Oa) of the straight line (La) and a tire external contour, an intersection (Ob) of the straight line (Lb) and the tire external contour, and an intersection (Oc) of the straight line (Lc) and the tire external contour.

A tire constructed with a plurality of reinforcement belts is provided. At least one of the reinforcement belts extends along the axial width of the tire summit and is constructed according to an equilibrium curve that is flat throughout the summit. The reinforcement belts include cable reinforcements that are substantially parallel to the equatorial plane. Substantial reductions in the tension experienced by the cables can be achieved to provide, as a result, improvements in e.g., tread wear.

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.

The aspect ratio of this tire 2 is not greater than 75%. The tire 2 includes: a carcass 12 extending from one bead 8 to the other bead 8; a belt 14 located between a tread 4 and the carcass 12; and a cushion layer 16 located between an end 54 of the belt 14 and the carcass 12. Each bead 8 includes a core 34 and an apex 36. The zone from the inner end of the cushion layer 16 to the outer end of the apex 36 is a flexible zone. The ratio of a length F in the radial direction of the flexible zone to a cross-sectional height A of the carcass 12 is not less than 0.25 and not greater than 0.4.

A pneumatic tire includes a carcass layer and a belt layer disposed outward of the carcass layer in the tire radial direction, and also includes, in a tread surface thereof, a plurality of circumferential main grooves and a plurality of land portions defined by the circumferential main grooves. In addition, when the tire is mounted on a specified rim, is inflated to 5% of a specified internal pressure, and is in an unloaded state, upon defining points P1, P2, and P3 on a carcass profile, a distance Da in the tire radial direction from an intersection point P1 to a point P2 and a distance Db in the tire radial direction from the point P2 to a point P3 have a relationship of DbDa.

A pneumatic tire is provided where a profile line in a tire meridian cross section of a center land portion defined by circumferential grooves and located on a tire equator is curved projecting outward in a tire radial direction. A carcass layer and a reinforcing layer include a recess portion curved projecting inward in the tire radial direction in a bottom region of the center land portion.

A radial tire for an aircraft, the radial tire having a rim diameter of 20 inches or less includes a pair of bead portions; a pair of sidewall portions extending outward from the bead portions in a substantially radial direction; a tread portion that couples together respective radial outer ends of the sidewall portions; a toroidal carcass layer reinforcing a portion between bead cores embedded in the bead portions; a belt layer and a tread that are sequentially laminated on an outer side of the carcass layer in the radial direction, wherein a value M obtained by dividing a tire external diameter D by a distance L between bead heels of the bead portions is in a range of from 4.1 to 5.4.

Provided is a pneumatic tire having at least one carcass layer as a skeleton extending in toroidal shape over a pair of bead portions, at least one belt layer and a tread disposed on an outer side in the radial direction of a crown portion of the carcass. In a tire section in the widthwise direction in state where the tire is assembled to an application rim, ratio BD/BW of radius difference BD between radius at a center portion and radius at an end portion in the widthwise direction of an innermost layer of the belt layer, to width BW of the innermost layer, ranges from 0.01 to 0.04, and ratio TD/TW of radius difference TD between radius at a center portion and radius at an end portion of the tread in the widthwise direction of a tread ground surface, to tread ground-contact width TW, satisfies BD/BW<TD/TW.