I found that Gates has a belt that works just great # 1632v210. To replace the belt just loosen set screw on the spindle and then remove the plate on the drive shaft and pull the upper pulley off the spindle. You can now remove belt. You now need someone with strong fingers to compress the spring so you can insert a small 5/8 x 5/8 block of wood between the sides of the movable spindle pulley. Place belt over both pulleys and slide the spindle pulley on then and remove the block of wood. This might take 10 minutes to complete. Good luck.