TKI Belt Drive fits all 2008-2017 XP, XS, XM chassis sleds except the new T3 Summit (available soon). This is the best belt drive on the market. TKI made us some new sprockets for the higher gear ratios. This belt drive reduces weight by about 7.5 pounds, spools the motor/driveline quicker and eliminates a broken chain exploding your chaincase. These use a Gates poly carbon drivebelt for the greatest durability. Installation requires no modification except slightly moving the battery on electric start models. Top Gears may be purchased separately so you can change ratios and are $79.95 each. The combos we use for the short trackers have a 54T or 58T bottom gear and 25 - 31t top gears are available. We also stock extra belts which can be purchased separately. Please call to order any extra gears or if you need help selecting gearing or clutching suggestion.