Polyester cords and their use in runflat tires

The present invention is directed to a runflat tire (10) having at least one of its components comprising the radial carcass ply (22), the underlay, the overlay, the bead inserts or the chippers, reinforced with polyester cords having a polyepoxide disposed on its surface. The polyester cord is formed by first obtaining a cord through twisting together a plurality of polyester yarns, secondly treating the cord with an aqueous dispersion comprising a polyepoxide, and optionally thirdly treating the cord with an aqueous RFL dispersion comprising a resorcinol-formaldehyde resin, a styrene-butadiene copolymer latex, a vinylpyridine-styrene-butadiene terpolymer latex, and a blocked isocyanate. The inventions also directed to such a cord and to a method to make such a cord.