An improved belt and tread drum incorporating an improved segment is disclosed. Segments are mounted in side-by-side relationship about a central axis for radial movement inwardly and outwardly with respect to the central axis and include arcuate outer surfaces that collectively define an outer circumferential working surface of the drum. The segments each define an arcuate outer surface defining a circumferential dimension, the outer surface having varied curvature along the circumferential dimension.