Abstract: A radial collapse tire building drum having a hub, a plurality of axially extending cylindrical body segments disposed around the hub, a first radial support at one axial end of the hub and supporting one axial end of the segments, a second radial support at the other axial end of the hub and supporting the other axial ends of the segments, and a collapsing mechanism disposed within the drum between the first and second radial supports and operable to move the segments either radially outwardly with respect to the hub to form a cylindrical body concentric with the hub, or radially inwardly towards the hub to collapse the cylindrical body of the drum. A main drive shaft is secured to the hub with its axis co-extensive with the hub axis and there is a hollow shaft through which the main drive shaft extends.