Method of providing an air passage in a tire and coated filament

A method of providing a passageway in a tire is disclosed. The method comprises providing a filament (58) coated with a coating material (92), the coating material (92) comprising at least one diene based elastomer and a material containing therein a liquid or a solid capable of generating a gas upon vaporization, decomposition, or a chemical reaction under heating; encasing the coated filament (104) into containment within an uncured or a pre-cured flexible tire component (70); building a green tire from tire components including the uncured or pre-cured flexible tire component (70) and the encased coated filament (104); curing the green tire including the flexible tire component (70) containing the coated filament (104); and removing the filament (58) from the cured flexible tire component to leave within the flexible tire component a substantially unobstructed air passageway (80). Furthermore, a coated filament comprising a filament (58) and a coating material (92) coating the filament (58) is disclosed. The coating material (92) comprises at least one diene based elastomer and a material containing therein a liquid or a solid capable of generating a gas upon vaporization, decomposition, or a chemical reaction under heating.