A conveyor belt roller having a pair of opposed double tracks or threads formed on the surface thereof. Each pair of tracks spirals around the roller a plurality of times to provide a respective double helix pattern track running left and right from the midpoint of said roller. Each respective double helix pattern track commences upon the roller surface at starting points positioned 180. degree. apart about the circumference of the roller, and extends to the respective ends of the roller. The roller also is provided with interchangeable bearing and shaft housings for mounting at the respective ends of the roller to maintain the same in desired disposition during operation of the conveyor belt associated with the roller.