BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: DAVE BRADY on 17 Apr, 2025, 17:21

Title: sintered clutch plate
Post by: DAVE BRADY on 17 Apr, 2025, 17:21
Hi,

Does or has anyone used sintered plates, as pictured, in their clutch?
If so, what is the advantage?

Dave.
Title: Re: sintered clutch plate
Post by: DAVE BRADY on 18 Apr, 2025, 10:23
Hi,

The image is from ebay and is listed for Triumph/BSA.  It definitely looks like a replacement for a plain plate that is slotted on the clutch hub.
Some Nortons use these but with a different centre and are described a friction plates.
If they are a friction plate for a Norton why would they be available to replace a plain plate in a Triumph or BSA?
If I fitted them in an A65 clutch in place of plain plates what would happen?

Dave.
Title: Re: sintered clutch plate
Post by: iansoady on 18 Apr, 2025, 13:15
I had a Commando with sintered plates and as you say they replaced the Feroso friction plates. It was a great clutch provided it was correctly built and adjusted - very light but no slip or drag.

I can see no point in replacing plain plates with them and indeed could foresee problems.
Title: Re: sintered clutch plate
Post by: DAVE BRADY on 18 Apr, 2025, 13:35
Hi,

I agree. It looks like they could cause a problem but I wonder why they are even available.
There must be some logic to it. I think I have four of these.

Dave.
Title: Re: sintered clutch plate
Post by: cdsdorset2 on 18 Apr, 2025, 16:17
At a guess its a form of oil flinger.
Title: Re: sintered clutch plate
Post by: DAVE BRADY on 18 Apr, 2025, 17:11
Hi,

I would think that the groove is there to serve perhaps to clear any excess oil. 
This is being sold as a clutch plate but to what advantage over a normal plain driven plate?

Dave.
Title: Re: sintered clutch plate
Post by: DAVE BRADY on 23 May, 2025, 10:20
Hi,

Update on the bronze clutch plates.

I tried using one of these sandwiched between two modified friction plates.  I removed the friction material from two friction plates and inserted the bronze plate between them so that the now smooth surfaces were against the bronze plate.
After a short road test I concluded that the bronze plates are not friction plates at all but replacements for the plain steel plates.
The only advantage that I could find is that they are more heat tolerant.
Sometimes when doing this sort of thing I think that perhaps BSA did have a bit of a clue and that 99% of the time standard is best.

Dave.
Title: Re: sintered clutch plate
Post by: V500 on 23 May, 2025, 11:12
I reckon the Ebay seller just posted the wrong pic...
Title: Re: sintered clutch plate
Post by: DAVE BRADY on 23 May, 2025, 11:39
Hi,

I think the pic. was correct but he did not necessarily know what they are.  I asked and He said friction but not the case.
No body seems to know anything about about these so the mystery remains.

Dave.