This invention relates to a friction drive mechanism for a motorized sliding door. The door is suspended by a first rail and its movement guided by a third rail. A second rail is flexibly coupled to the first and biased against a motorized driving roller by a simple tensioning mechanism. The tensioning mechanism maintains the friction contact between the driving roller and the second rail. The flexible coupling joining the first and second rails compensates for any misalignment in the mounting of the componentry. The flexible mounting also allows for the door to be driven around curves.