A tire can include beads, a carcass, sidewall layers, a tread, a belt, and a band. A carcass ply of the carcass can include a ply body and a pair of turned-up portions. An end of each turned-up portion can be located axially inward of an end of the belt. A ratio of a thickness from the carcass to an outer surface of the tire along a first normal line to a thickness from the carcass to the outer surface of the tire along a second normal line can be not less than 1 and not greater than 2.

A multi-strand cord (50) comprises 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 SL40 000 MPa.Math.mm with $SL=\max \left(\frac{{}_{\mathrm{bending}\_\mathrm{CI}}}{\mathrm{Cp}};\frac{{}_{\mathrm{bending}\_\mathrm{CE}}}{C_r\mathrm{Cp}}\right);$
and a size criterion Ec0.46 with Ec=Sc/Se.

The present invention relates to an eco-friendly tire cord and a tire using the eco-friendly tire cord, in which use of a recycled polyethylene terephthalate (PET) fiber reduces environmental load and also provides physical properties equivalent to or better than those of a tire cord that is produced by application of a virgin PET fiber and particularly, excellent heat resistance equivalent to or better than that of a tire cord produced by application of a virgin PET.

A tire can include beads, a carcass, sidewall layers, a tread, a belt, and a band. A carcass ply of the carcass can include a ply body and a pair of turned-up portions. An end of each turned-up portion can be located axially inward of an end of the belt. A ratio of a thickness from the carcass to an outer surface of the tire along a first normal line to a thickness from the carcass to the outer surface of the tire along a second normal line can be not less than 1 and not greater than 2.

In a tire, a point (Au) on a side profile at the same position in a radial direction as an end portion of an innermost layer of a belt layer is defined in a cross-sectional view in a meridian direction. A distance (Hu) from a maximum width position (Ac) to the point (Au) in the radial direction is defined. A point (Au) on the side profile at the radial position of 70% of the distance (Hu) from the maximum width position is defined. A point (An) on the side profile at the radial position of 35% of the distance (Hu) from the maximum width position is defined. A radius of curvature (RP) (mm) of an arc passing through the maximum width position, the point (Au), and the point (An) with respect to a cross-sectional height (SH) (mm) is in a range 0.20RP/SH1.80.

An aircraft radial tire, having a radial carcass reinforcement with a plurality of carcass layers made up of textile reinforcing elements oriented substantially radially, which is to say making an angle of between 75 and 105 with the circumferential direction, the radial reinforcing elements of the carcass layers are composite cords having at least one aramid filament yarn and of which the rupture force is FR, measured in accordance with the standard D885/D885M-10A (2014) and these elements exhibit a deformation at least equal to 4.6% and at most equal to 6.5% for an applied force equal to FR/4. The tenacity of these reinforcing elements is at least equal to 80 daN/mm.sup.2, and the linear density of the aramid filament yarn or yarns exceeds 210 tex.

In a pneumatic tire provided with a carcass layer and a belt layer, the carcass layer is formed of an organic fiber cord having an elongation at break of 20% to 30%, an elongation in a sidewall portion under a load of 2.0 cN/dtex of 5.5% to 8.0%, and a product A=DEc of a fineness based on corrected mass D (unit: dtex/piece) and a count Ec (unit: piece/50 mm) of 1.810.sup.5 dtex/50 mm to 3.010.sup.5 dtex/50 mm, and the belt layer is formed of a steel cord having a stress at break of 3300 MPa or more and a product B=SEb of a cross-sectional area S (unit: mm.sup.2/piece), and a count Eb (unit: piece/50 mm) is from 6.0 mm.sup.2/50 mm to 7.5 mm.sup.2/50 mm.