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Bronze clutch plates

Discussion in 'Norton Commando Motorcycles (Classic)' started by htown16, Apr 5, 2019.

  1. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    The 71 that I am currently building was missing all of it's primary innards. I bought a complete set of everything including the spacers and shims. When I opened up the clutch I found it had bronze plates which I guess indicates the stuff came off an 850 or that someone had substitued bronze plates in a 750. Two questions:
    If the stuff came from an 850 will it work on my 71?
    Second, I'm inclined to use the bronze plates and see how they work. They don't seem to be too worn. If no good it's a relatively easy job to change to Barnetts which I've used in other bikes. Is there anything differenct I need to do to use the bronze plates.
     
  2. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Yes.

    Assuming you have the correct parts there should be five bronze plates, four plain and the 'thin' pressure plate. The bronze plate clutch had a hardened clutch centre.
     
  3. alan hodge

    alan hodge VIP MEMBER

    Joined:
    Oct 10, 2017
    well...the primary innard pieces I got for my 73 engine i got from a guy who went to belt contained bronze plates I cleaned them and they work as well if not better than the cork Surflex ones in my 72 Triumph...but that's just me
     
  4. ashman

    ashman

    Joined:
    Jul 11, 2010
    I am still using my orginal bronze and steel plates that been in there for over 43 years now and have over 160,000 miles on them, I have used them with chain drive as well as belt drive and they are still working like they should, just do the maintenance on them when needed and you won't have any problems with them, the only things I have replaced was the pressure plate and clutch centre once in althoughs years of riding, my clutch is light and has always been from new.

    Ashley
     
  5. Peter R

    Peter R

    Joined:
    Dec 13, 2010
    The Barnett plates are much lighter than the bronze clutch plates, and will alleviate the life of the gearbox. An alloy clutch basket and belt drive also helps here.
     
    Fast Eddie likes this.
  6. ashman

    ashman

    Joined:
    Jul 11, 2010
    Well mines been working fine for 43 years of riding, gear changes and clutch operation is as good as the day I rolled it out of the dearers door back in 1976.

    Ashley
     
  7. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    Mine have been in since '74. If I've done my part correctly they continue to do theirs. I have found them to be slightly more tolerant of oil in that they clean up so much more easily than standard friction material. The wear factor is very strong as stated by Ashman.
    I had issues in the early years until I learned to read English rather than HD or Honda when I piddled with it.
     
  8. Peter R

    Peter R

    Joined:
    Dec 13, 2010
    Indeed, works well with the original setup, you may not notice the difference with the lighter clutch, but your gearbox cerainly will.
     
  9. ludwig

    ludwig

    Joined:
    Aug 30, 2006
    Great , but how and where do you ride ?
    Using the clutch only once an hour , or every 2 seconds can make a difference :

    Stuart highway :

    [​IMG]

    Asietta , Italy :

    [​IMG]
     
  10. Danno

    Danno

    Joined:
    Feb 7, 2010
    The bronze plates I had in the SS clone always slipped when it came on the pipe. Put in Barnett clutch pack and no more slippage. Recently replaced the Barnett plates with new as some were right at the wear limit.

    The clutch in The Titanic had bronze AND fiber plates alternating. There were enough fibers of usable spec leftover that I was able to take out the bronzes and make it a fiber clutch pack.
     
  11. ashman

    ashman

    Joined:
    Jul 11, 2010
    For all my Norton's life its been a street bike dueing the week riding suburan streets and tight twisty country rides on the weekends I avoid straight highway riding if possible so boring, I am only about 15 minutes away from the mountains before all the fun starts, the Great Deviding Range runs all the way up the east coast of Australia so where ever you live on the east coast of Australia there is always a few many mountain ranges to choose from and you have to cross these ranges to get to inland Australia, the ranges run close to the coast in lots of parts and very hard to aviod them, if you look at a map of East Australia you see how long the Great Deviding Range is, looking over 3,000 miles or more from bottom to top of the east coast.
    But of course I do my maintenance and the first few years my Norton suffered lots of clutch slipping from the wrong oil being used, till I found the right oil to run in the primary and not over filling my gear box.

    Ashley
     
  12. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    I usually run ATF in my primary with fiber plates. Would you do the same with bronze?
     
  13. ashman

    ashman

    Joined:
    Jul 11, 2010
    Thats what I have been using for some years now and no problems at all, remember the oil is only to splash up on the primary chain to keep it lubed so between 5 and 7 fl ozs at the most, my clutch plates are normaly dry when I do my maintenance on them.

    Ashley
     
  14. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    Once I actually began to measure the oil going into the primary my clutch slippage ceased, and as stated above when inspected plates were found to be dry for the most part. When low I open the case and drain it starting from scratch to avoid overfill.....My forks work better with proper capacity also & oil tank ditto, so I take it the capacities listed in the manual are serious.
     
  15. ashman

    ashman

    Joined:
    Jul 11, 2010
    A good messuring cup or cups are your best friend in your workshop, my old cup has metric as well fl ozs and other messurements on it, its well used and been using the same cup for over 40 years now, I have seen where people have over filled there primary thinking that the chain has to be completely submerged in it but really it splashes onto the chain from the motor running, over 7 fl ozs and the clutch plates will get oil on them, to much oil and the clutch will suffer slippage.
    I always go by the Norton bible (workshop manuals)

    Ashley
     
  16. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    I use a 60cc syringe available at the pharmacy & just stick a rubber hose on it if I have to have some reach. If oil tank gets a little too much it just is sucked out on the spot. Too bad I wasn't as precise in the machine's early years, but it had to be going and not sitting. Now time is 75% maintenance/25% riding I believe. Constantly monitoring things.
     
  17. ashman

    ashman

    Joined:
    Jul 11, 2010
    Mine is the opposite 95% riding and 5% maintenance, do the maintenance when due or if something needs repairing or replaced or improve where needed, my Norton is well sorted and not much fails or needs fixing and its been like that most of its riding life, its no show pony and is showing its age but thats the way I like it.

    Ashley
     
  18. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    Mine sat 38yrs. and I keep careful watch on it. I probably shouldn't have done that, but parts at the time were very hard to chase down and terribly expensive(mostly poor quality after market too). So I opted to stow it and wait for the DAY....Well...If I'd waited much longer I'd be gone and mama would have had it in a garage sale for fifty bucks or less because neither of the boys really knows what it is... They know it's noisy & pretty fast considering the age, but couldn't manage to start it much less ride it and survive. My grandson is really it's only hope and he can't find the joystick. Hopefully one steps up to take stewardship before I go because it's more than just another bike to me.
     
    Gord Brown and MichaelB like this.
  19. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    Do the early bikes not have a level plug?
    With the MK3 filled to the level plug or a bit more, no slip, no drag. There is lots of ATF on the plates tho, in this case Barnett Kevlar, made to run in oil.

    Glen
     
  20. Danno

    Danno

    Joined:
    Feb 7, 2010
    Bronzes ought to work fine with a belt-drive primary.
     

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