 The first CMTs were commercially-available Goodyear Custom Steelguards, and Goodyear Tire and Rubber Company produced all CMT tires from 1975 until 1984.From 1984 to 1991, the CMT tires were produced by Uniroyal.CMT tires are now "specially designed and built to American Society for Testing and Materials (ASTM) standard E1136 to have particularly narrow limits of variability."