V-belts used for racing have a grater amount of their weight to the outside. Ones that don't want to flip-over to get the heaviest part outward. The greater the RPMs, the greater the tendency to flip. Pulley misalignment just makes the situation worse, as the belt tends to crawl up one side of the the sheave, giving clearance for the belt to try flipping. Of course, improper tension is the most common issue, as too tight fries your bearings, and too loose allows belts to slip and flip at speed. Worn pulleys are another contributor to flipping.What is a outside-mass belt?