Abstract: A device for preventing a pinch puncture of an inner tube of a pneumatic tire, which is disposed within a tire casing fitted over a wheel rim, includes a resiliently deformable ring disposed between the inner tube and the rim. The ring includes a flat base section positioned within a radially outwardly facing channel of the rim, an intermediate section which extends from the base section radially outwardly substantially beyond an outer periphery of the rim, and an outer section which defines an inner tube supporting cradle. The intermediate section of the ring includes a neck having a reduced width relative to the base section. The outer section has a width greater than that of the base. A radial aperture is provided through the ring for a valve stem, and a valve stem extension is provided to extend from the inner tube valve stem radially inwardly through the rim. The ring is preferably formed of a polyurethane material having a 90 Shore A durometer hardness.