QRS XP4 Progressive Secondary Clutch Helix for Ski-Doo 850 E-TEC (Long Track / Mountain - High Elevation) // SKU: 05-XP4

SKU: 05-XP4

Clutch Compatibility: Ski-Doo OEM QRS Secondary / Driven Clutches

Primary Application: Ski-Doo REV Gen4 & Gen5 850 E-TEC mountain sleds (Summit & Freeride) riding at 6,000+ ft.

Eliminate belt slippage, prevent high-altitude RPM fade, and maximize track horsepower in deep snow with the Bikeman Performance QRS XP4 Progressive Secondary Clutch Helix. In thin mountain air, the factory Ski-Doo secondary helix angle upshifts too aggressively, forcing the clutches apart under heavy load, causing belt slippage, extreme sheave heat, and lost track speed on steep technical climbs.

Our XP4 progressive angle solves this by managing the QRS secondary sheave separation rate throughout the entire shift curve. It starts at an aggressive angle for explosive off-the-line throttle pickup and rapid track speed build, then smoothly transitions to a shallower angle that exerts immense clamping force across the drive belt. The result is continuous belt grip, dramatically cooler clutch operating temperatures, and lightning-fast backshifting the millisecond you let off the throttle in technical tree lines.

Key Performance Features

• High-Elevation Profile: Specifically profiled for the torque curve of the 850 E-TEC twin when fighting deep powder and steep incline resistance above 6,000 feet.
• Progressive Dual-Angle Design: Launches hard off the line and seamlessly transitions into a high-pressure clamp angle to prevent belt slippage during wide-open-throttle climbing.
• Instantaneous Backshifting: Squeezes back down on the belt instantly when you dump and re-engage the throttle, keeping the 850 E-TEC pinned in its 7,900–8,000 RPM sweet spot without bogging.
• Substantial Belt Heat Reduction: Eliminating secondary slip slashes sheave and belt surface temperatures, dramatically extending drive belt lifespan on long mountain pulls.
• Aerospace-Grade Billet Aluminum: Precision CNC-machined from high-tensile billet aluminum to hold micro-tolerances, resist ramp deflection, and prevent roller grooving.
• Essential Kit Component: This is the exact secondary helix included in our Ski-Doo 850 E-TEC Long Track High Elevation Stage 2 Clutch Kit.

Fitment & Installation Notes

• Vehicle Compatibility: Fits all 2017+ Ski-Doo REV Gen4 and Gen5 850 E-TEC mountain models (Summit, Summit Expert, Freeride) equipped with factory QRS driven clutches.
• Recommended Maintenance Upgrade: We strongly advise inspecting your secondary clutch rollers during helix installation. Upgrading to our Heavy-Duty BRP QRS Secondary Clutch Rollers prevents premature flat-spotting and roller failure common to the OEM composite rollers.
• Clutch Tooling: Requires a standard Ski-Doo QRS secondary clutch compression tool for safe disassembly and reassembly.