A runflat safety insert and safety tire and wheel assembly which include a take-apart multi-piece wheel rim and safety inserts extending circumferentially around the rim to clamp the tire bead toes against the rim bead flanges. The insert is a sheet metal annulus of generally channel shape in radial cross section open at its radially inner periphery between its side edges. The annular has a central bight portion extending generally axially and bounded by radially in-turned leg portions. The leg portions diverge relative to one another radially inwardly towards the tire bead toes and terminates in toe portions bearing generally flat against the interior surfaces of the tire toe beads. An elastomeric tread is bonded to the outer surface of the central bight portion. The annulus is made up of a pair of semi-circular members having interengageable mating ends releasably interconnected to form a complete annulus. The insert tread extends radially outwardly therefrom a predetermined distance to have a clearance with the interior surface of the tire under normal running conditions. The sheet metal annulus is axially compressed by the engagement of the tire bead toes with the channel toes so that the channel is stressed in direct opposition to stresses imposed on the same when the tire and rim combination is operated without inflation pressure in the tire chamber.