High-Performance Clutch Kit with Extra Plate / '98-'17 Big Twin

An extra friction plate over stock, 11 percent more surface area and a stronger diaphragm spring, for big twins making more than they left the factory with.

A clutch slips when the torque coming through it exceeds what the friction area and the spring can hold. Belt Drives attacks both. This kit runs ten friction plates instead of the stock count, on 6061-T6 aluminum cores, which puts 11 percent more friction surface in the same basket, and it adds a diaphragm spring rated 10 percent stronger than stock to clamp it. That is the combination that keeps a big bore or a cammed motor from cooking a stock pack, and the plates are supplied at a pre-measured stack height so the assembly goes in without shimming.

Features of the High-Performance Clutch Kit

• Ten friction plates on 6061-T6 aluminum cores
• Nine tempered steel drive plates
• Diaphragm spring 10 percent stronger than stock
• 11 percent more friction surface area for more positive engagement
• Suited to big bore builds and other high torque applications
• Pre-measured stack height for straightforward installation
• Made in the U.S.A.

High-Performance Clutch Kit Fitment

• '98-'17 Harley-Davidson Big Twin

Not for models with the slipper or assist clutch.

⚠️ VERIFY whether your bike has an assist and slip clutch before ordering. Harley-Davidson phased the assist clutch in on some models late in this range, and the pack is not interchangeable.

Common Questions About the Belt Drives Clutch Kit

Will the lever pull get heavier?
Slightly. The diaphragm spring is 10 percent stronger than stock, and that is felt at the lever. If you want the holding power without the extra effort, a ramped or hydraulic assist is the usual answer.

Do I need to measure the stack height?
Belt Drives supplies the plates pre-measured as a set. Check the total against your service manual spec anyway before the pressure plate goes on; basket wear on a high mileage bike can change the answer.

Is a stronger spring enough on its own?
Not usually. Spring pressure without added friction area drives lever effort up and wears plates faster. This kit adds the tenth plate first, then backs it with the spring, which is why the surface area figure matters more than the spring figure.

Works With

Refresh the release side at the same time with the Heavy Duty Throwout Bearing Kit, and hold the pack with a Billet Pressure Plate.