A process of manufacturing tires having a crown reinforcement from one or more liquid or pasty materials which solidify in a core mold is improved due to the fact that prior to the filling of the mold there is placed in the mold an elastically deformable annular net formed of two superimposed plies of parallel wires crossed from one ply to the other at an angle at most equal to 90.degree. with respect to the circumferential direction of the tire, at least the outside of the wires being formed of an elastic and weldable material permitting welding of the wires of one ply to those of the other ply at the points where they intersect, the net being placed in the mold with its edges equidistant from the equatorial plane of the tire.