SMC highly recommends cleaning clutch discs mechanically NOT chemically. We have found that brake cleaner and other chemicals are inadequate for removing dirt and other fine particles packed into the tiny voids. A stainless steel utility brush aka plater’s brush with a wire diameter of .006 is ideal for removing the hard-to-get-at dirt. Try this yourself and see the difference with a magnifying glass. Better yet, put a piece of white paper under the disc while brushing it. Check out the dirt!

The friction material is very porous and consequently works very well as a dirt collector. Once the voids are filled and packed, the dirt starts to act as a lubricant (think tiny ball bearings) and causes the clutch to slip for a greater distance.

Clutches like tires get dirty quickly. It is important to clean clutch discs every race weekend if not every heat if you want maximum acceleration. 

Pictured above is a NEW clutch disc. The left side has not been brushed and the right side brushed with a stainless steel utility brush. Even a new friction disc benefits from a light brushing. 

Pictured above is a USED clutch disc. The left side has not been brushed and right side lightly brushed with a stainless steel utility brush.