Patrick Custom Carbon is known for its radical carbon fiber body panels for snowmobiles. But it wants to be known for something more performance-related: clutching.
What is it?
Patrick Custom Carbon sent us a set of clutches for our Polaris 850 Pro RMK 163 test sled last season. This included a P-85 primary clutch and a Team LWT secondary clutch.
But these were no stock clutches. Patrick Custom Carbon gave these clutches the works treatment, doing everything in their power to lighten and balance the clutches and improve their efficiency.
Starting with the P-85 primary, Patrick Custom Carbon machined the fixed sheave to lighten the rotating mass. Then it replaced the aluminum cover with a Patrick Custom Carbon lightweight carbon fiber cover and replaced the original steel bolts with titanium bolts for another reduction in rotating mass.
Finally, Patrick Custom Carbon balanced the P-85 primary. It’s interesting to note that just lightening the fixed sheave and upgrading to the carbon fiber cover puts the clutch more in balance than it was when it came off the sled. That’s cool. The added balancing gets the balance to incredible tolerances (see spin data sheet).
The Team LWT secondary clutch underwent similar treatment. The fixed sheave was machined to make it lighter, and the movable sheave as well. Then the clutch was spin-balanced on Patrick Custom Carbon’s high-tech equipment.
What does it do?
There are three key factors of Patrick Custom Carbon clutch balancing to consider.
1. Reduced rotating mass.
When you reduce the weight of things that spin, you get more horsepower from the engine to the track. The drivetrain responds quicker, so your throttle response is improved and acceleration is better. Your engine and drivetrain efficiency goes way up.
2. Reduced vibration.
A perfectly balanced clutch smoothes out a lot of the vibration you feel in the handlebars and running boards. That also helps with durability, prolonging bearing life.
3. Heat reduction.
Clutches that work more efficiently and don’t vibrate generate less heat. The byproduct of that is longer belt life.