Clutch Slip on Commando 750

Hi Andy, I went through the same fear myself and was very concerned about resurrecting the old clutch slip problem when I went back to chain primary drive. I can report that I reused my original clutch (bronze plates) and since fitting the Alton starter have covered several thousand miles without any issues from the clutch. I donât know why? The only thing thatâs different is that I put straight 30 motor oil in the primary drive (only because I have this old can of âCastroliteâ straight 30 that was originally my Dads, I have no idea how old it is). I recall back in the dayâs before I fitted the belt drive I used ATF (which seemed to be recommended by most back then) Iâve had my RGM belt drive since 1999, just about to use it on another Commando Iâm reassembling.Regards, Alan

Hi Alan,Thanks for the heads-up, very interesting. I always used a 20-50 oil. I used to clean up the plates every 500 miles or even less, it was really annoying. I wonder if the diaphram plate loses some pressure over the years? The bike was 23 years old when I bought it in 95. I have had no reason to change the plate and the clutch is perfect. I did fit the Norvil clutch actuating rod nut with internal rubber seal as in fact oil from the gearbox found its way onto the plates and they became sticky, which meant a very clunky first gear change. Since then faultless.

I think I will continue with the kick start while my knees hold out! (75 and counting...). Luckily the old girl is a first kick starter so at the moment not a problem.

Good luck with the new bike.

Andy

Previously Andrew Heathwood wrote:

Andy & Alan

Castrolite formulations seem to have varied over the years and as far as I know it is now unavailable. In the early 1970s Castrolite was a 10W-30 weight oil. I'd try one of the following:

Motol Transoil 10W-30

http://www.opieoils.co.uk/c-786-10w-30-bike-gear-oil.aspx

Lucas Primary Chaincase Oil

http://www.lucasoil.co.uk/index.php/products/motorcycle-products/oils/lucas-hd-primary-chaincase-oil

Both are designed for use with wet clutches and the Motol oil looks to be a close match to the Castrolite of the 1970s.

I use the Motol oil in my 1972 Roadster without any slip problems but ATF worked okay as well.

Andy

Hi Andy,You will see my reply to Alan. I do like the idea of a very light oil you identify. Let's see if there are any other comments.

Cheers,

Andy B

Previously ronald_proctor wrote:

Hi Andy,my 750 Commando is still using the solid fibre clutch plates that it's had from new.It used to need the clutch stripping and the plates washing in petrol every month or so to cure the slip/drag due to oil contamination.All now completely cured by using one of the special clutch centre nuts with the pushrod seal from Norvil,as it's the gearbox oil creeping along the mainshaft centre which contaminates the plates,not the primary case oil.The clutch is now excellent-no slip,no drag,and the fitting of an extra plain steel plate has resulted in a lovely light action,all highly recommended!

Ron Proctor.

Hi Ron, very interesting. As you can see from my reply above I too fitted the clutch-rod seal, but that was after I fitted the belt drive as I was still experiencing a problem, although to be fair it was not slippage, just binding. Cured it anyway.

My clutch is still as fitted back in 1972. I think I tried the extra plate at some stage as I have one in my"box of bits".

All food for thought!

Andy

Previously mark_woodward wrote:

Hi Andy, I have an Alton starter on my 920 Commando fitted with a RGM belt drive (no clutch slip). The Alton instructions include notes on fitting the starter kit to belt drive bikes. I'd suggest that you might like to look at that option prior to thinking of reverting to chain drive. The instructions are available from Altons website.

HtH

Hi Mark, thanks for the comment re Altons. Something has changed then as when I looked into the matter some while back I was told by Alton that "ce n'etait pas possible".

I will certainly take your advice and check their website.

Thinking about it I think my RGM belt is wider than the ones now being offered, and that may have been the problem.

Previously boo_cock wrote:

Don't waste your time farting about with modifications ans different oils. Hi Torque plates from RGM and TQF auto transmision oil works brilliantly. I have used it for ages without a problem. If you want to play around with stack height later to get an easy action clutch you can, but for now just change the plates and oil and give it a good thrash up a steep hill with a fat passenger and feel smug!

Hi,Sounds like a good answer. I like RGM and perhaps should have spoken to Roger or Lawrence before I aired the matter on the NOC website. I did not know they offered an updated set of plates. To be fair, I have not needed any.I think what I will do is to upgrade the clutch, refit the chain drive and use one of the oils recommended by you and others. If there is no slippage with my very slender wife on the back up our local unsteep hills, (Suffolk) I will order up the Alton kit.

I wonder if any member has fitted the American kit? Looks a fine bit of engineering, just one or two compromises such as the air filter box, (not that I use one), and it quite pricey and perhaps overly chunky.

I've not used the NOC forum before, despite being a member for 21 years. It's pretty good for unbiased information.

Previously David Comeau wrote:

At first I breezed this thread and did not see a clutch rod seal mentioned but tonight I did...Norvil indeed does sell my Commando clutch rod seal. I made my first one in about 1989 for myself and the local club members. It was designed using the concept off a Brit side car racers rig, but you could not buy them....anywhere So I designed made my own. now..1000 at a time.

While I personally do not advertise them, they seem to sell OK. well over 5, 000 to date.

I offered them to RGM many years ago and the discussion degraded very rapidly..why??

I offered them to NOC parts scheme and got no response ????

The actual response from users has mostly been very good. It does not fix all clutch problems but for $20 retail (how much $$$ are clutch packs?) most people fix their yearly maintenance into 5 years or more.

Every one of my Nortons is still on their original clutches. Some are belt drive and they are bone dry...

Cheers

Dave

http://atlanticgreen.com/store.htm

Good for you, Dave. I fitted the unit years ago after reading about it in the NOC mag, which I guess was when Norvil offered it.

My own invention is a means of filling the swinging-arm oil resevoir. Since all the items were "borrowed" from my wife's kitchen drawer I have to careful about disseminating the info. Suffice to say it includes a cake icing device, for which she is still searching... I might send a pic to the mag.

Andy