ROTAX 850 E-TEC ENGINE: The most powerful 2-stroke engine in the industry. * It pumps out 10 more horsepower (165 hp) than its predecessor, but its responsiveness is what really shines. With the new pDrive primary clutch, it’s 30% quicker responding than the 800R E-TEC giving you the instant control you demand. *Observed HP measured on internal dyno test in optimal conditions for 2-stroke engines. REV GEN4 PLATFORM: The 4th generation of the REV platform is designed around aggressive trail riders with a narrow, compact package giving the rider more freedom to move and influence the sled. More centralized masses (especially side-to-side), light weight and industry-leading suspensions make the vehicle ultra responsive. PDRIVE CLUTCH: A major factor in the quickness of REV Gen4 sleds is the new pDrive clutch. Fast and friction-free dual rollers transfer torque in place of traditional sliding buttons on this 100% new clutch. The oversize rollers with needle bearings, wide flyweights and shaft-on-shaft design emphasize smooth operation and long life. Ultra-responsive shifting, impressive RPM consistency and 2.8 lb./ 1.3 kg lighter than the TRA VII. RS RUNNING BOARDS: Designed for aggressive stand-up riding, they are flatter for most of their length, wider and strong. Thicker aluminum sheet (3 mm vs. 1.8 mm), plus front and rear reinforcements to withstand tough landings. RMOTION 129 REAR SUSPENSION: The standard for control, capability, comfort and adjustability – with added traction, better braking and more bump filtration in 129-inch (327 cm) version. Separate spring and shock dynamics, plus the most rising-rate/progressive motion ratio in the industry give the rMotion suspension its supple ride in small bumps with added capability in large ones. Easy adjustments for shocks, springs and coupling block. RAS 3 FRONT SUSPENSION: Precise, predictable handling and outstanding bump absorption, even in harsh conditions, with State-of-the-art unequal length A-arm front suspension with rack steering. ERGO-STEP SIDE PANELS: Design enables you to slide naturally to three different cornering styles, including a new, extreme-forward position. KYB PRO SHOCKS: Designed to the same high standards as the MXZx 600RS race sled - so you know they're extremely capable and durable for control in the toughest conditions. Remote reservoir design performance and they are rebuildable/revalvable. Easy Adjust compression damping knob requires no tools; rebound adjustments are standard on front shocks also.