I have come up with a combination of clutching and gearing that improves the performance and belt life of the new XP's. I am not the guy who will bore you with the theories and reason's why this clutching works. I will bore you with I rode the sled stock and realized that the clutching was way off. I have tried many combinations and can tell you that this combo was a big improvement. This kit will work at 3-7K feet and I am pretty sure it would work at higher elevations with a pin adjustment but I have not tested it there so I will not claim that it works at higher elevations. The kit would cost $250 and would include a helix, primary spring, Adjustable pin kit, and chaincase gear. PM me to express interest. Thanks