Aluminum versus Steel Friction Plates

[Northracing]

I see Surflex sells clutch plate kits with steel or aluminum friction plates. Is there any downside to using the aluminum ones in a single, like increased expansion or rapid wear of the tangs on the clutch basket?

I figure less reciprocating mass is a good thing but don't want to bring any problems with the lighter friction plates.

Thanks.

[IanHood]

I would be wary of the aluminium plates in a single. They do tend to wear out more quickly than steel plates (unsurprisingly) and aluminium particles will end up in the oil. Pretty sure that’s not a good thing for an engine without any really effective filtering.

Ian

[themoudie]

Aye Northracing,

In the clutch there shouldn't be any "reciprocating mass"!

The aluminium alloy clutch plates that you speak of, are I think, the alloy cored friction plates (Surflex 274 M 19), rather than the more commonly used steel cored friction plates (Surflex 34 M 34)?

Whether the tangs of the alloy friction plates would notch and not freely slide, along the clutch basket tangs, when operating the clutch is a bit "Suck it and see"!

Yes, their reduced weight would reduce the mass of the clutch as a whole, theoretically reducing the inertia in the clutch to rotate and requiring less power to achieve a specific engine RPM. But, whether it would be a noticeable advantage on a road engine would be debateable, I think.

Sparkly oil, due to increased wear on the plate tangs and increased maintenance, along with a potential reduced service life, would dissuade me from going down the route of using the alloy cored friction plates. The coarse gauze oil strainer is unlikely to strain out the fine aluminium flakes, if they are allowed to build up in the oil they are likely to become smeared in the ball bearings and across the bushes in the engine and that doesn't make sense to me either.

However, if racing is the goal and you are changing the oil after every meeting and the monetary pit that is racing beckons, only you know how deep your pit is.

This is the link to the current (2025) Surflex catalogue, and pages 19 to 21 are the pages to view, if you wish to see my reference. I use Google translater to translate the pdf catalogue descriptions: 2025_Surflex_Ducati_clutch plates_catalogue_listings_Italian

Good health, BillR