A radial tire carcass fabricated by a first stage process has bead portions which are placed over a pair of spaced-apart coaxial bead seats. The bead seats may be segmented radially expandable rings which are expanded by fluid pressure into engagement with the bead portions. The tire carcass is initially positioned on the drum with the bead seats at a spaced-apart distance so that upon expansion of the segments of the bead seats at a low pressure and axial movement apart of the bead seats the ply of the tire carcass is stretched and the bead portions moved into register on the bead seats. The fluid pressure expanding the segments of the bead seats is then increased to secure the bead portions on the bead seats at predetermined positions with a predetermined diameter. Annular sealing members may be mounted on the segments of the bead seats at the tire-supporting surfaces of the segments for compression upon application of high pressure. The sealing members may also have flaps for bridging the space between the bead portions of the tire and mounting rings for the segments of the bead seats so that the tire may be inflated after registration of the bead portions and while the bead seats are moved axially together for the application of the tread and belt ply.