Method of manufacturing pneumatic tubular tires

A method of manufacturing a pneumatic tubular tire having a tubular cross section in a radial direction of the tire and comprising a tread portion, side portions and a bottom portion, comprising the steps of:

• 1. coaxially aligning a core of a split mold assembly having an outer peripheral surface coincident with an inner profile of a base tire composed of the bottom portion, contiguous side portions and a continuous opening corresponding to the tread portion in a circumferential direction of the tire, within separable mold members of the split mold assembly having an inner peripheral surface coincident with an outer profile of the base tire to define a first molding cavity therebetween;
• 2. molding a fluidizable high polymer material, selected from the group consisting of polyurethane-based polymers, thermoplastic resins, thermoset resins, natural rubbers and synthetic resins, in the first molding cavity to form the base tire;
• 3. separating the separable mold members and core to remove the molded base tire;
• 4. setting the molded base tire within a tread ring of a centrifugal molding machine having an inner peripheral surface corresponding to an outer peripheral surface of the tread portion and part of the side portions to define a second molding cavity in the continuous opening;
• 5. pouring a fluidizable high polymer material of a low viscosity thermoset resin selected from the group consisting of polyether urethane resins and polyester urethane resins into the second molding cavity by centrifugal force to mold the tread portion and hence produce a final tire;
• and
• 6. removing the tire product having a desired tubular cross section from the tread ring.