Radial tire sidewall reinforcement

A radial tire comprising a crown reinforced by a crown reinforcement comprising at least two plies of rubber reinforced by cables or wires crossed from one ply to the next and surmounted radially by a tread designed to be in contact with the ground, two beads designed to be in contact with seats of a mounting rim, each bead being extended by a sidewall comprising a radial carcass reinforcement formed of at least one ply of rubber reinforced by a plurality of cables or wires, the said carcass reinforcement extending into the crown and being anchored in each bead to at least on element that is inextensible in the circumferential direction, the said tire comprising in at least one sidewall a supplementary reinforcement, wherein, when viewed in meridian cross-section:

• the supplementary reinforcement comprises at least two groups each formed of at least two strips that extend in the circumferential direction;
• each strip, of width Li essentially equal to or greater than the total width Lt of the supplementary reinforcement divided by the total number of strips in the group concerned, is formed of rubber reinforced by a plurality of cables or wires inclined at an angle α between 30° and 90°, the angle being measured on a new tire relative to the circumferential direction;
• within any one group, each circumferential strip is superimposed partially over an adjacent strip, to avoid gaps between the strips;
• the supplementary reinforcement is arranged radially on the inside of the carcass reinforcement in the at least one sidewall, and a layer of rubber mixture separates the carcass reinforcement from the supplementary reinforcement, the rubber mixture having a modulus at 10% elongation that is lower than the modulus at 10% elongation of a rubber mixture of the carcass reinforcement.