Crown reinforcement for a radial tire

A tire, comprising a radial carcass reinforcement surmounted by a crown reinforcement formed of at least one working reinforcement formed of two working plies of inextensible metallic reinforcement elements, which working plies are parallel to each other within each ply and are crossed from one ply to the next, forming with the circumferential direction angles α1 and α2 of between 10° and 45°, the radially inner and the radially outer of said working plies having axial widths L1 and L2, respectively, and of at least one protective ply of axial width L3 wherein L3<L2<L1, said at least one protective ply being radially outward of said radially outer working ply and having reinforcement elements inclined in the same direction as the reinforcement elements of the radially adjacent outer working ply, wherein there is arranged on either side of the equatorial plane XX′ of the tire, in the axial extension of the at least one protective ply, at least one additional ply of inextensible metallic reinforcement elements of the same direction as that of the reinforcement elements of the radially outer working ply and forming with the circumferential direction an angle α4 greater in absolute value than the angle α2 of the elements of the radially outer working ply by at least 5°, the axial width LA of each said additional ply being such that its axially outer end is distant from the equatorial plane XX′ by an amount greater than half the width of the least wide and radially outer working ply, and such that the additional ply does not cover the axial end of the widest and radially inner working ply, said axially outer end of said at least one additional ply being located at a distance from the equatorial plane XX′ of the tire of between 42.5% and 47.5% of the axial width L1 of the radially inner working ply.