A tire design for a heavy-duty vehicle of construction plant type has a crown reinforcement (40) radially on the inside of a tread (10) and radially on the outside of a carcass reinforcement (70). The carcass reinforcement (70) has at least two carcass layers (50, 60) having metal reinforcers coated in an elastomer compound. The carcass layers (50, 60) have respective stiffnesses per unit width R1, R2. Metal reinforcers of a first carcass layer (50) form, with the circumferential direction (XX′), an angle A1, and those of the second carcass layer form an angle A2, such that the angles A1 and A2, and the stiffnesses R1 and R2, simultaneously satisfy the following three relationships: R1*sin 2(2*A1)+R2*sin 2(2*A2)≥(R1+R2)*) sin 2(30°), and ∥A1|-|A2∥<10°, and 0.7≤R1/R2≤1.3. The metal reinforcers have a critical compression buckling deformation DF at least equal to 2.5% and a compression elastic modulus MC at least equal to 10 GPa.

In a pneumatic tire, at least one carcass layer mounted between a pair of bead portions is formed from a carcass cord formed of an organic fiber cord having filament bundles of organic fibers intertwined together, a fineness based on corrected mass of the carcass cord is from 4000 dtex to 8000 dtex, an intermediate elongation of the carcass cord at a sidewall portion under 1.0 cN/dtex load is from 3.3% to 4.2%, and a ratio G/R of an interlayer rubber gauge G between a body portion and a folded back portion to a cord diameter R of the carcass cord, at a contact region where the body portion and the folded back portion are in contact in the carcass layer, is from 0.50 to 0.60.

To provide a tire that is not only improved in durability, steering stability, and low rolling resistance in high-speed driving but also excellent in tire productivity. A tire including a pair of bead cores (11), a carcass including at least one carcass ply (12) extending between the pair of bead cores (11), a belt (13) including at least one belt layer placed outward in a tire radial direction of the carcass, and at least one belt reinforcement layer (14) placed outward in a tire radial direction of the belt (13), in which a reinforcement cord of at least one of the carcass ply (12) and the belt reinforcement layer (14) includes a cord using a polyamide multifilament including a polycondensate of a dicarboxylic acid including an aromatic dicarboxylic acid with a diamine.

A rubberized reinforcing ply (1) for articles consisting of an elastomeric material, preferably for vehicle tires, wherein the reinforcing ply (1) has a multiplicity of textile strengthening members (2) which are arranged parallel to and spaced apart from one another, wherein each textile strengthening member (2) is composed of at least one twisted multifilament yarn, and wherein the textile strengthening member (2) is not composed of the material rayon. The reinforcing ply (1) satisfies the following condition: (D.sup.2/E.sub.0) in mm corresponds to a value in a range from 0.22 mm to 0.38 mm, and the reinforcing ply (1) has a strength of >10 kN/dm, where D is the diameter of the textile strengthening member (2) in mm and lies in a range from 0.38 mm to 0.52 mm, and where E.sub.0=100/epdm.

The invention relates to a multi-strand cord (50) comprising an internal layer (CI) of the cord made up of K=1 three-layer (C1, C2, C3) internal strand (TI), with the internal layer (C1) being made up of Q internal metallic threads (F1), the intermediate layer (C2) being made up of M intermediate metallic threads (F2) and the external layer (C3) being made up of N external metallic threads (F3), and an external layer (CE) of the cord made up of L>1 three-layer (C1′, C2′, C3′) external strands (TE) wound around the internal layer (CI) of the cord, with the internal layer (C1′) being made up of Q′ internal metallic threads (F1′), the intermediate layer (C2′) being made up of M′ intermediate metallic threads (F2′) and the external layer (C3′) being made up of N′ external metallic threads (F3′).

The cord (50) has: an endurance criterion SL≤40 000 MPa.Math.mm with

[00001]$SL=\max \left(\frac{\Delta {\sigma }_{\mathrm{bending}\_\mathrm{CI}}}{\mathrm{Cp}};\frac{\Delta {\sigma }_{\mathrm{bending}\_\mathrm{CE}}}{C_r\times \mathrm{Cp}}\right);$  and a size criterion Ec≥0.46 with Ec=Sc/Se.

In a pneumatic tire, a plurality of belt layers disposed on an outer circumferential side of a carcass layer in a tread portion are formed of steel cords each having a 1×M structure formed of a number of wire strands. The number of wire strands corresponds to one to six wire strands. A tensile modulus of elasticity of the steel cords under 5 N to 50 N load is 130 GPa or more. The steel cords are arranged inclined with respect to a tire circumferential direction to intersect each other in layers of the belt layers. The 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 helically along the tire circumferential direction.

In a pneumatic tire, at least one carcass layer mounted between a pair of bead portions is formed from a carcass cord formed of an organic fiber cord having filament bundles of organic fibers intertwined together, a fineness based on corrected mass of the carcass cord is from 4000 dtex to 8000 dtex, an intermediate elongation of the carcass cord at the sidewall portion under 1.0 cN/dtex load is from 3.3% to 4.2%, and an elongation at breakage of the carcass cord is 20% or more, and a ratio G/R of an interval between adjacent carcass cords within the carcass layer at a tire maximum width position to a cord diameter of the carcass cord is from 0.35 to 0.60.

A tyre for vehicle wheels comprises a support structure and a tread band arranged in a radially outer position with respect to the support structure. The support structure comprises a plurality of hybrid reinforcing cords (10). Each of the hybrid reinforcing cords (10) has at least two strands (20) twisted together with a predetermined twisting pitch. Each of said at least two strands (20) comprises at least one monofilament textile wire (21) and at least one multifilament textile yarn (22) comprising a plurality of textile filaments (22a). In any cross section of the hybrid reinforcing cord (10), said at least one monofilament textile wire (21) is at least partially embedded in the filaments (22a) of said at least one multifilament textile yarn (22).

A tyre (1) for motorcycles comprises a carcass structure (2), a belt structure (10) applied in radially outer position with respect to the carcass structure (2), a tread band (11) applied in radially outer position with respect to the belt structure (10), wherein the carcass structure (2) comprises at least one carcass ply (3). The carcass ply (3) comprises a plurality of reinforcing cords (20) comprising a first end (21) and a second end (22) twisted together, wherein the first end (21) is a hybrid yarn (23) comprising a plurality of first filaments (24) mixed with a plurality of second filaments (25), wherein the filaments of the plurality of first filaments (24) are made from a single material having a first modulus and wherein the filaments of the plurality of second filaments (25) are made from a single material having a second modulus different from the first modulus. The second end (22) is a textile yarn (28) comprising a plurality of third filaments (29) made from at least one material having a third modulus.

In a pneumatic tire, at least one carcass layer mounted between a pair of bead portions is formed from a carcass cord formed of an organic fiber cord having filament bundles of organic fibers intertwined together, a fineness based on corrected mass of the carcass cord is from 4000 dtex to 8000 dtex, an intermediate elongation of the carcass cord at a sidewall portion under 1.0 cN/dtex load is from 3.3% to 4.2%, and a ratio G/R of an interlayer rubber gauge G between a body portion and a folded back portion to a cord diameter R of the carcass cord, at a contact region where the body portion and the folded back portion are in contact in the carcass layer, is from 0.50 to 0.60.