The present invention is directed to a method of constructing a tire, comprising:constructing a coated filament, the coated filament constructed by coating a filament with a coating material, the coating material comprising at least one diene based elastomer and heat expandable thermoplastic resin particles containing therein a liquid or solid capable of generating a gas upon vaporization, decomposition, or a chemical reaction under heating;encasing the coated filament into containment within an uncured or pre-cured flexible tire component;building a green tire from tire components including the uncured or pre-cured flexible tire component and the encased coated filament;curing the green tire including the flexible tire component containing the coated filament;removing the filament from the cured flexible tire component to leave within the flexible tire component a substantially unobstructed air passageway.