Method and apparatus for stabilizing a tire building drum wherein the tire building drum has two ends, is permanently supported at a single cantilever support end, and the remaining end is a free end. The method comprises providing a free end support engaged with the free end to stabilize the tire building drum by restricting lateral movement of the free end; and freeing the free end by temporarily retracting the free end support when desired, e.g., to enable application of annular tire components on the tire building drum, or to enable removal of a built tire from the tire building drum. Preferably, the free end support allows rotation of the tire building drum while the free end support is engaged with the free end. A preferred embodiment uses overtravel of actuator linkages stopped against an extension stop to lock the free end support in place, engaged with the free end, to stabilize the tire building drum without requiring continued power input.