Tire with crown reinforcement including half-plies

A tire with a form ratio smaller than 0.80, comprising a radial carcass reinforcement consisting of at least one ply of non-extensible metallic reinforcement elements, and covered radially by a working crown reinforcement consisting of at least two working crown plies which are axially continuous and are formed of non-extensible metallic reinforcement elements parallel to one another within each ply and crossed over from one ply to the next such that they make angles α, α′ relative to the circumferential direction between 10° and 45°, the tire characterized in that the two working plies have axial widths, respectively, in the ranges 0.65SO to 0.80SO and 0.35SO to 0.45SO, SO being the maximum axial width of the median line of the carcass reinforcement, the working crown reinforcement being completed by the presence of at least two half-plies of non-extensible metallic elements which make an angle β relative to the circumferential direction, β being smaller than the angles α and α′, by at least 2°, and in the direction opposite to that of the angle α of the widest axially continuous working ply, the said half-plies being positioned on either side of the equatorial plane XX′ with axial widths between 0.22SO and 0.35SO, such that their axially inside edges are separated from the equatorial plane XX′ by a distance equal to half the width of the narrower working ply less an amount at least equal to 0.05SO.