Abstract: A rubber, radially expansible ring in a tire building drum is provided for gripping the bead of a tire carcass. The ring is radially expansible in a continuous, circumferential channel of the drum. The ring has an outer surface suitably shaped for holding the bead of the tire carcass, and a pair of continuous, circumferential pressure sealing flaps extending inwardly from both sides of the ring. The flaps are adapted for sealing engagement with adjacent side members of the circumferential channel, so that the ring may be radially expanded without the use of an inflatable bladder. This abstract is not to be taken either as a complete exposition or as a limitation of the present invention, however, the full nature and extent of the invention being discernible only by reference to and from the entire disclosure.