I pulled the clutch plates for the first since buying this 850 and found the friction plates were made up of 3 fiber & 2 Bronze and the it looks like two of the flat plates are steel but the other two look bronze. I should have checked with a magnet but haven't yet. Is this a common practice to mix up the fiber & bronze friction plates ??. Two of the fiber plates are within the .142 / .148 thickness spec but one is .140 so I guess I will at least be replacing that plate but would you guy's start over with a complete new set? And if so, Sintered bronze or Fiber??? I did a search but didn't really find a concense or if mixing them up is ok. Before it got a bit of gear oil in it & strayed slipping it was great! Any opinions? Thanks.

gtsun wrote: Before it got a bit of gear oil in it & strayed slipping it was great! ....

i think you answered your question (not sure what strayed slipping means, but think you mean it started slipping )

Just my advice:

I would call Colorado Norton Works and have them send you a complete set of 850 plates, new steel driven and new barnett friction plates.

I did this a couple months ago, the price for a complete set seamed reasonable to me, under $100.

You will be good to go for a very long time with all new plates.

And since you now have the old plates out, how is your center hub?

If it is all notched and knackered up, this is good time to put a new one in, otherwise just a good cleaning.

Yep get new plates, Don't mix and match.
Barnett are great, check the hub, and at least consider doing the push rod seal kit.
AC.

Ya I think I will replace the whole set. My center hub is a bit beat up. It will be getting replaced & I decided since I have a new chain & don't know how old the existing one is it's getting replaced too. So is it kind of 50/50 on the Sintered bronze verses the Fiber type friction plate preferance??

New age advice is quite correct to suggest buy all new and vendors agree. Past tradition was mix and match stack so spring just slips in slot and adjust as usual and enjoy as you already know works just fine, until cooked oil burnished as can happen to any of them. To complete your mis match kit some are known to keep 3 thck-nesses of pressure plates on hand.

Yes as above dont mix, but if you go with original style bronze plates you may want to try this mod and it doesn't matter how much oil you get in there, they won't slip.
5 x slots on either side of the plate in the bronze only with a Dremel 2 mm cutting disc. When doing opposite sides of the plate, offset each slot so they are in different positions from one side of the plate to the other. I run my engine oil in the primary chain case with original plates and no slip. My circlip gets into the slot comfortably so stack height is good and doesn't need shimming (at this stage!!!)
Regards Mike

Don't know about Barnett. When I first got my 73 running the clutch was terrible. no good travel, short engagement, dragged. It was a barnett. I could never get the stack hieght right no matter what. After months I finally gave up and ordered a set of stock bronze plates. I kept the original steel plates. It works perfectly and even if I get some tranny oil migrating in there, it doesn't seem to both it in the least. While expensive, it was well worth it. Just my opinion and experience.

Hi gtsun

On the race bike I have run fibre bronze steel. A few of the vintage lads run the bronze as they are superb & dont slip however they Bang on driving out of corners i.e. on or off People add one or two fibre plates to soften this up a bit .
John Seeley 920 has run an all fibre clutch without changing it for years.
All my problems with Norton clutches have always been because the centers are worn. Slipping no gearchange whatever. Get the stack height right & they work & work well.
Chris

Interesting Chris, thanks for posting that. I thought there might be a reson why the PO had mixed them up. I have to say that before it started slipping witch I guess is from gear oil & I have ordered a clutch rod seal from dynodave to stop that. The clutch was real nice. Easy pull, no harsh take off & it would lift the front wheel if I was a bit crazy. I am ordering a new complete Barrnet plate kit. Old Britts is around $86.00 & CNW is around $98.00 and Matt called them " Bar-Flex" plates. Are these differant than the Old Britts plates? Does Barrnet sell two types for the 850s or are the Barrnet friction plates all the same???

I had a problem with a set of Barnett friction plates around 10 years ago.

It may have been a bad batch because the bonding tended to wear quickly on the friction pads and loosen.

Since then I have gone through two other new sets of Barnett clutch plates with no issues, just normal wear.

The previous set lasted ten years.

I can't answer your question as to why CNW's cost is a little more than Old Britts.

I order from both companies, a new clutch center hub from Old Britts recently.