A door operator having a door hanger comprising a pair of double trolley assemblies disposed for linear movement within a hanger rail, wherein each trolley assembly further comprises two rollers mounted substantially opposite one another and engaging roller cavities within said hanger rail. Said door hanger is integrated with the drive system or is mounted independently of the drive system for replacement of the door hanger of the prior art or in new application requiring such independency between the door hanger and drive system.