A mold (22) includes a bead ring (32). The bead ring (32) includes a side
forming surface (34), a bottom forming surface (36), a support surface
(38) for a bladder, and a guide surface (40) for a bladder. The support
surface (38) is positioned on an inside in a radial direction of the
bottom forming surface (36). The support surface (38) is extended in the
radial direction. A distance (L2) of the support surface (38) is equal to
or smaller than 5.0 mm in the radial direction. The guide surface (40) is
positioned on an inside in the radial direction and an outside in an
axial direction from the support surface (38). The guide surface (40) is
inclined inward in the axial direction from the inside in the radial
direction toward an outside in the radial direction. An angle .theta. of
the guide surface (40) to the radial direction is equal to or greater
than 15 degrees and is equal to or smaller than 75 degrees. In an
expansion, a bladder (B) is erected by the guide surface (40). By a
further expansion, the bladder (B) is supported by the support surface
(38).