Abstract: A suspension system for a heavy duty industrial door has a double guide track system which provides smoother operation and resistance to jamming due to the effects of wind or negative air pressure. Respective guide tracks can be disposed at 90.degree. angles, and a similarly designed support carriage having a pair of traveling support devices disposed at right angles engage each of the guide tracks for supporting associated sections of a flexible door. The suspension system according to the invention is particularly adapted for use with folding industrial doors which comprise a series of overlapping flexible plastic strips which depend from hinged rack sections.