A method of forming a reinforcing fabric and in particular a body ply for a radial tire. A continuous narrow ribbon, which is formed of an uncured elastomeric material having a plurality of spaced substantially parallel reinforcing means, preferably individual steel filaments, embedded in the elastomeric material and extending along the length of the ribbon, is helically wound on a cylindrical drum with successive turns of the ribbon overlapping one another to form a cylinder whose wall thickness is greater than the thickness of the ribbon. The helical winding of the ribbon is continued until the length of the wound cylinder is approximately equal to the circumference of the bead of the radial tire to be produced. The wound ribbon is removed from the drum, flattened to form a sheet of material of the length of the wound cylinder, formed into a further cylinder whose longitudinal axis is transverse to the longitudinal axis of the sheet, and the two juxtaposed ends of the sheet are joined to form the body ply of the radial tire.