A bond of a rubbery component to a virgin surface of a tire's cured innerliner which virgin surface has never been contaminated by the remnants of a release agent left after buffing with a wire brush and solvent-cleaning the cured innerliner, is unexpectedly stronger than a bond of the component to the contaminated but "cleaned surface", cleaned as indicated. As an alternative, buffing with a wire brush results in a textured surface that impairs adhesion of a balance pad. Therefore, a pneumatic tire is provided with a virgin surface protected against contamination by a release agent at the curing temperature of the tire; protection is provided by a self-supporting barrier film of sulfur non-vulcanizable, expandable, thermoformable synthetic resinous material; and, a method is provided for maintaining a virgin cured surface within all or part of either the exterior or interior of a pneumatic tire's rubber carcass which is conventionally cured. The barrier film which is substantially inextensible at ambient temperature, is removable without tearing into pieces from the protected surface of the cured tire. When the interior surface is provided by an innerliner, any component to be included within the interior of the carcass may be adhesively secured to the virgin surface of the innerliner more securely than has been heretofore possible.