A support assembly is provided for a roller tube having a sheet material wound therearound. The support assembly has opposed first and second mounts adapted to support the roller tube, which is rotatably coupled to the mounts. At least one support cradle is disposed between the first and second mounts. The support cradle is configured to support the roller tube along a length thereof A biasing member is arranged to reduce a force of the roller tube in a direction toward the support cradle, thereby preventing the sheet material from binding against the support cradle as it winds and/or unwinds.