L.A.B. said:
By 'open' I meant that the clutch is not designed to keep oil out! Brittwin, if you should actually take the trouble to inspect a clutch you should see that the standard Commando drum actually has HOLES in the outer drum circumference where excess oil can escape from the clutch. Oil is NOT TRAPPED IN THE HOUSING BY THE SPRING!
Of the three Mk.III's I had, only one of the (triplex chain) clutch baskets had a few tiny peripheral "oil escape holes" in them - they didn't look the business.
My first Commando was my regular (almost daily) transport for ten years, the second and third were bought as "spare parts carriers", but I eventually also restored the latter two. I sold all three Commandoes (all Mk. III's) between 1991 and 2002 due to heavy, painful spine problems (intervertebral discs) emerging, causing considerable immobilisation. I just mention this to tell you I've been working intensely on Mk.III Commandoes for 17 years..... :wink:
L.A.B. said:
If that truly was the case then the plates would slip as soon as they got oil on them, and I am sure from my own experience and reading about the experiences of others (here and elsewhere) that there are many Commando owners that still have standard clutches fitted and experience no problems (myself included) under normal conditions, but yes I do agree they can benefit from an *ocasional* clean up.
The "clutch slip" problems of my frist stock MK.III became noticeable after some time / mileage, I rode this bike for 10 years and over 75,000 mls), and I
always encountered clutch slip after, say, every 2,500 - 3,500 mls. A thorough cleaning job then recftified matters for another 3,000 mls. I also used a home-made pushrod-tunnel seal which did a perfect job, so gearbox oil entering the clutch wasn't the problem. After approx. 15,000 mls I got tired of all this and a Norvil belt drive kit with "sureflex" fibre friction plates (running dry) cured the problems.
L.A.B. said:
Can bronze and steel become 'soaked'? I am not trying to infer that the clutch would not work better dry I am just saying that it does generally work OK as it is.
The Mk.III "bronze" clutch plates are a porous sinter material job which tends to keep oil in it, thus "sweating it out" when becoming hot (friction!), a desirable property of bearing materials but no good for clutch plates. After becoming aware of this, I regularly cleaned the bronze plates in a solvent bath (acetone) for approx. 12 hrs, which thoroughly removed the oil. However, the improvement was minimal - it simply gave me, say, 500 more "slip-free" miles.
The Norvil belt drive kit gave me approx. 20,000 maintenance-free miles (first leg) instead, I only had to open the primary drive after that mileage to replace the final drive sprocket (worn), and the (sealed) clutch roller bearing (a a precaution). Then the bike was good for another 35,000 mls (second leg), and even after that time the belt hadn't shown any significant signs of wear whatsoever. Quite impressive, IMHO.
L.A.B. said:
Yes obviously, but from what you originally said you appeared to infer that the hydraulic tensioner was a common fitment to Commandos. I was merely bringing this to the attention of anyone who might have thought that.
Sorry for conveying that impression, I was of course solely referring to the Mk.III OEM primary drive. IMHO it makes more sense to replace a MK.III's primary drive train with a belt drive kit than that of earlier Commandoes - because it simply eliminates more problems and maintenance issues therewith.
I think that actiually riding a Commando a lot makes it a very desirable achievement to get at least partially rid of it's archaic, intensive maintenance scheme, giving it a more favorable ratio of "mainteance & repair vs riding" hours. That is to say "ride more, and have less problems to fix". In due course, I advocate electronic ignitions, automatic cam chain tensioners, and of course primary belt drives as well as other, unobtrusive improvements which are not too obvious to the naked eye. A matter of individual "taste", if you want, and certainly nothing a Commando owner would want to do if he'd like to keep is bike "100% stock/original".