BRP Reveals New Vibration Damping Clutch Technology
There has been a flurry of allegations circulating the internet lately about supposed poor quality control of clutch components manufactured by BRP and installed in Ski-doo Gen4 850 sleds from 2017, including the Summit.
The speculation seems largely based on the findings of a few individuals who have discovered—upon close inspection of clutch sheave components—the existence of a measurable offset on the sheave faces.
As a result, BRP has released the following information with regards to its patent pending process which intentionally engineers a .024″ offset into the clutch sheave as an innovative way to reduce engine vibration from its high output E-TEC 850cc displacement engine.
Brp Reveals New Vibration Damping Clutch Technology
Since the launch of the REV Gen 4 platform, BRP has been using a Patent Pending technology on the pDrive clutch to minimize engine vibration. This unique new solution adds no weight but solves the vibration issue many large displacement two-cylinder snowmobile engines experience.
To minimize vibration from the extra 50cc’s, extra 10 horsepower and 30% faster response of the Rotax 850 E-TEC, Ski-Doo engineers designed an industry first, counterbalancing pDrive fixed clutch sheave.
Those with a keen technical eye will notice the D-Shaped crankshaft alignment and the twenty four thousandths (.024) of an inch (.6mm) precise offset or runout built into the clutch sheave. This runout keeps the belt more perfectly tensioned within the primary and secondary clutches to reduce vibrations sent into the chassis through the secondary clutch.
The timing of the runout’s high spot meeting the belt is synchronized with the engine’s firing to offer a counterbalancing effect without added weight or complexity. The net result is less vibration transferred into the chassis and the rider.
Because of reduced vibration transferred to the belt, the belt temperature remains stable or even cooler, compared to not having this runout.