A pneumatic radial tire includes belt layers disposed on an outer circumferential side of a carcass layer in a tread portion. The belt layers are formed of steel cords in a N+M structure in which the number of wire strands N of an inner layer is 2 to 4 and the number of wire strands M of an outer layer is 2 to 7. A twist direction of the inner layer is different from a twist direction of the outer layer. The steel cords are inclined with respect to a tire circumferential direction to intersect each other in layers of the belt layers. A belt cover layer disposed on an outer circumferential side of the belt layers is formed of organic fiber cords having elongation of 2.0% to 4.0% under 2.0 cN/dtex load. The organic fiber cords are wound spirally along the tire circumferential direction.

A pneumatic tire comprises a carcass layer, a belt layer radially outward of the carcass layer, and a tread rubber radially outward of the belt layer. The belt layer includes an angle belt having a belt angle ≥45° and ≤70° in absolute values, a pair of cross belts having belt angles of ≥10° and ≤45° in absolute values and having belt angles of mutually opposite signs, and a reinforcing layer having a belt angle within ±5° relative to a circumferential direction. A width Ws of the reinforcing layer and a cross-sectional width Wca of the carcass layer satisfy 0.60≤Ws/Wca≤0.70. The cross belts are radially outward of the large angle belt. The reinforcing layer is radially inward of the pair of cross belts. A width Wb2 of a wider cross belt of the pair and Wca satisfy 0.79≤Wb2/Wca≤0.89.

Provided is a pneumatic tire. A belt cover layer made of an organic fiber cord spirally wound along the tire circumferential direction is provided on the outer circumferential side of a belt layer in a tread portion, and a polyethylene terephthalate fiber cord of which the elastic modulus under a load of 2.0 cN/dtex at 100° C. is in the range of 3.5 cN/(tex.Math.%) to 5.5 cN/(tex.Math.%) is used as the organic fiber cord. The coating rubber covering the organic fiber cord contains one or more of natural rubber, styrene-butadiene rubber, or butadiene rubber as a rubber component. The coating rubber is formed of a rubber composition in which the content of natural rubber in the rubber component is 50 mass % or more, and 5.0 parts by mass to 9.0 parts by mass of zinc oxide is blended per 100 parts by mass of the rubber component.

In a pneumatic tire, a belt cover layer is provided on an outer circumferential side of a belt layer in a tread portion and includes organic fiber cords helically wound along a tire circumferential direction. As the organic fiber cord, a polyethylene terephthalate fiber cord is used which has a single yarn size fineness of 700 dtex or less and in which the number of twists is 30 twists or more/100 mm. A layer thickness of the belt cover layer is 1.6 times or more as large as a cord diameter of the organic fiber cord.

A radial tire (1) for a heavy-duty vehicle of construction plant type, and aims to increase the rupture strength of the hoop reinforcement thereof having circumferential layers, ensuring satisfactory endurance of the crown reinforcement thereof. According to the invention, the at least one circumferential hooping layer (71, 72) comprises a median portion (711, 721) having a median width (L11, L21) and a median tensile elastic modulus (E11, E21), and two lateral portions (712, 722) that axially extend the median portion (711, 721) on either side and each have a lateral width (L12, L22) and a lateral tensile elastic modulus (E12, E22), the lateral width (L12, L22) is at least equal to 0.05 times the median width (L11, L21), and the lateral tensile elastic modulus (E12, E22) is at most equal to 0.9 times the median tensile elastic modulus (E11, E21).

Provided is a pneumatic tire that includes a belt reinforcing layer formed of an organic fiber cord. A belt layer disposed on an outer circumferential side of a carcass layer in a tread portion is formed of monofilament wires having a wire diameter of 0.30 mm or more and 0.45 mm or less. The belt reinforcing layer is disposed on an outer circumferential side of the belt layer, is formed of an organic fiber cord that is made of a polyethylene terephthalate fiber and has an intermediate elongation under 2.0 cN/dtex load of from 2.0% to 4.0%.

A pneumatic tire for use on trucks, the tire comprising: a tread which includes a belt reinforcement structure, the belt structure including a pair of working belts, wherein the angle of the working belts range from about 10 degrees to about 50 degrees, and wherein the first working belt has an angle of the reinforcements different that the angle of the belt reinforcements of the second working belt. The belt package further includes a low angle belt that is preferably positioned between of the working belts, wherein the angle of the low angle belt is less than 5 degrees. The working belts and the low angle belt are extensible, and preferably made of high elongation wire. The pneumatic tire further includes a wherein the tread is formed of a treadcap compound having a tensile at break greater than 18 MPa, and an elongation at break greater than 450%.

A pneumatic tire for use on trucks, the tire comprising: a tread which includes a belt reinforcement structure, the belt structure including a pair of working belts, wherein the angle of the working belts range from about 10 degrees to about 50 degrees, and wherein the first working belt has an angle of the reinforcements different that the angle of the belt reinforcements of the second working belt. The belt package further includes a low angle belt that is preferably positioned between of the working belts. The pneumatic tire further includes a tread having a groove reinforced with a tread compound having a tensile at break greater than 18 MPa, and an elongation at break greater than 450%.

A pneumatic radial tire is provided that includes belt layers disposed on an outer circumferential side of a carcass layer in a tread portion, and a belt cover layer disposed on an outer circumferential side of the belt layers, the belt cover layer including organic fiber cords helically wound along a tire circumferential direction, the belt layers including steel cords arranged at an incline with respect to the tire circumferential direction in such a manner as to intersect one another between the layers, each of the belt layers having a bending rigidity of 16500 N.Math.mm.sup.2/.sub.50 mm or less per 50 mm width in a direction orthogonal to a longitudinal direction of the steel cords, and the belt cover layer including organic fiber cords having an elongation of 2.0% to 4.0% under a load of 2.0 cN/dtex, the organic fiber cords being helically wound along the tire circumferential direction.

A tire (1) for an agricultural vehicle, having a crown reinforcement (3), with at least two crown layers (31, 32), each having metal reinforcers which are coated in an elastomer material. Any metal reinforcer of a crown layer (31, 32) has a law, known as a bi-modulus law, governing its elastic behaviour under tension, comprising a first portion having a first extension modulus MG1 at most equal to 30 GPa, and a second portion having a second extension modulus MG2 at least equal to 2 times the first extension modulus MG1, and any metal reinforcer of a crown layer (31, 32) has a law governing its behaviour under compression that is characterized by a critical buckling strain EU at least equal to 3%.