Pro-Ride Progressive-Rate Rear Suspension: A stronger, stiffer chassis creates less flex, allowing the front end to be planted firmly in the corners, delivering sharper handling, less ski lift and greater control. Pro-Ride Progressive-Rate Rear Suspension: Pro-Ride gets progressively stiffer through its travel for a smoother more controlled ride and protects from bottoming out on big bumps similar to a motocross bike. Liberty 600 CFI Engine: The new Polaris Rush is powered by our proven Liberty 600 Cleanfire Engine, one of the strongest and most highly praised 600s in the industry. Delivering award winning power with class leading acceleration and Polaris quality. Rider Active Control: Introducing true rider active control anticipate and respond to any trail condition or obstacle using body input to affect your sled, slide back on the seat for serious weight transfer, slide forward to set the front end for cornering with maximum bite. You're in control not the terrain. 1.25 Inch Ripsaw Track: The 600 Rush features an upgraded track: The 121 inch Ripsaw track with 1.25 inch lugs.