New clutch plates or not?

I am performing a complete engine overhaul on my 74' Commando, top and bottom end. Replacing all the service wear items I can, swing arm bushes and spindle, isolastics etc. When it comes to my clutch, I am not sure if I need to replace plates or not. These old bronze plates and the plain plates are flat and seemed to work well before tear down. Will I see better clutch performance from a New bonded Barnett set up? Thank you for your replies!

Those bronze plates hardly ever wear out. They should be .125" thick.

Same thing with swing arm bushings they don’t usually wear out the play is usually in the cradle.

I am still running my stock bronze and steel plates from new and my clutch is light one finger pull if i want, all i do with them every year or so i pull them out and give them a good clean and inspection, depends on the miles i clock up each year, my Norton was a everyday rider till 2013 but still regularly ridden and has over 160k miles on the clutch, been running ATF in the primary since 1982 have never had sticking plates since, have never checked stack height since new, i can't work out why do many have problems using bronze plates as my clutch has always been light and smooth from new, coming up to 50 years in my hands this June.
I even used my bronze plates ehen i ran a belt drive and no oil for 3 years before going back to chain.

Ashley

Jonez69 said:

I am performing a complete engine overhaul on my 74' Commando, top and bottom end. Replacing all the service wear items I can, swing arm bushes and spindle, isolastics etc. When it comes to my clutch, I am not sure if I need to replace plates or not. These old bronze plates and the plain plates are flat and seemed to work well before tear down. Will I see better clutch performance from a New bonded Barnett set up? Thank you for your replies!
View attachment 123266

Click to expand...

You need to read and understand all that is at play.

One man, has done untold hours of research and testing, and is kind enough to make the information available.
If you follow this info, you will have a great clutch.



The information on DynoDave's website is accurate technical data, and not to be confused with anecdotal fluff as compiled on other self proclaimed "expert" web sites.

I chose to use the Barnett plates based on wisdom from poster "bill".
The no slip, no drag, buttery smooth & linear clutch is perfect.

The bronze plates are resting comfortably in a box, as new thickness. While durable, I found them grabby.

My 850 Roadster has a belt drive and Barnett clutch plates. It has been bullet proof for 15,000 miles. Before that I had
bronze clutch plates that would slip at WOT no matter how well cleaned.

My 850 Roadster is totally original except that I substituted one 2mm steel clutch plate for a 3mm one from RGM. That
turned an unacceptably hard clutch pull into a firm but quite easy pull. It still has the original bronze clutch plates, cleaned
and flat but at WOT they slip but otherwise work fine. Yes, I have the Dyno Dave clutch rod seal.

If you are happy with clutch performance as is, no need to replace plates. I went chasing how to lower the lever force needed to apply clutch on my 850 as my hand would cramp up when riding in urban traffic for long periods. Tried different thickness pressure plates from RGM and that made for a dramitcally lighter lever. But later found slippage at max torque situations. Needed more fettling I suppose but a barnet plate pack came up on sale and i went that route. Stack height became much closer to ideal without any modified pressure plate thickness, lever was light and never any slippage. I guess original bronzers had worn enough over 30k miles to change stack height and require greater lever force.

If you are happy with your clutch performance or not depends a lot on the type of road you ride. On a typical American road, you use your clutch maybe 10 times over 100 km. On dirt roads likely more than a 1000 times over the same distance.

I replaced my bronze plates about 2 years ago.
When I got my new surflex plates I measured both old bronze and Surflex and thought that
the Surflex were too thick and the wrong part. My bronze plates were under .115 each (I forget exactly).

I was told no, the Surflex were spec and they were. When I put them in, my clutch pull went far lighter. I
did not realize how much the war bronze had changed the diaphragm geometry to result in a much heavier pull.
Now with much less pull required, the geometry still ensures the clutch engages properly with no slipping
Dennis

I just ordered the Barnett set of plain and friction plates from Colorado Norton Works. A new clutch center as well, plus the clutch rod seal they offer.
CNW's prices were a pleasant surprise, actually!