Check you primary lube

Just as an FYI to my fellow Nortoneers -

A buddy of mine allowed the oil in his primary chaincase to leak out (buggered o-ring), and after only 1500 miles his primary chain has stretched beyond service life. It's so loose that the lower run of chain is dragging on the inner primary case. Lucky it didn't break apart.

His bike is a tad ratty - he says it's "protected" by a film of oil and dirt - so he didn't even notice the leak.

I'm gonna make it a point to pull the filler inspection screw once in a while on mine.

Intentionally drained mine a couple of years ago and have been running it dry since. It cuts way down on leaks. The belt doesn't seem to mind...

I have to admit that I don't really check the chaincase regularly. But the bike's pretty much oil-tight so it would be pretty obvious. On my old original '71 I used to open the drain screw every so often, dump a bit of motor oil in until it ran out of the drain, wait until it quit draining and put the drain screw back in. On my 850 I occasionally run my finger along the bottom of the chaincase/cover joint and since it never comes up with any ATF, I don't check the level at all. In the old days that would have meant the chaincase was empty!
But now that I understand more about trued surfaces, overtightening, etc, the oil stays where it's supposed to.

If you look carefully you see how I take care of leaking primaries. :mrgreen:

Belt drive: a solution for which there is no problem...

But what the heck, if it wasn't for alleged "upgrades" a lot of folks would be out of business.

MexicoMike said:

Belt drive: a solution for which there is no problem...

Click to expand...

If there wasn't a problem then this thread wouldn't exist. :mrgreen:

Besides, aren't you the guy who put a Mukuni on your bike? :roll:

"If there wasn't a problem then this thread wouldn't exist."

The issue was about leaks; fixing the leak is the solution; putting in system that is not as strong and reliable as what was supplied by the factory is a marketing victory, nothing else.

"Besides, aren't you the guy who put a Mukuni on your bike?"
The odds of me putting a carb OTHER than a pair of Mk1 Amal Concentrics on my Commando is about the same as the odds of me winning the lottery without buying a ticket! You are apparently confusing me with someone else.

Losing 4 kg of weight from your drive train would hardly be a solution without a problem. It gives your gearbox a much easier time, is smoother and trouble free. With Barnett clutch plates My drive train has been no problem at all. I also don't have to free the clutch plates every time I jump on the bike.

We should all acquire 2-Two Cdo's one to exercise one desire to upgrade and modify and another plain jane all factory to test your manhood and mechanic wits.

Most the fastest and longest endurance test Commando won were done with the old school stuff. Triplex chain works fine and solving leaks is part of ownership and maturity to win in the end. I like ATF Type F for primary chain but only enough to just touch bottom sag links. I've had crank nut come off and jam into cover to make it spray oil out and punched cracks to outside. Hammered, filed, sanded, buffed it out, new 0-ring and ATF tight. I've also cheated with various goops, which work but a haasle as primary is something that needs opening up now and them, more than TS cover in my cases.

Everyone loves a clean machine. Well most do.

Never have had to "free" clutch plates nor have I ever had any issue with the Commando clutch that has anything to do with it being in there with oil (as it is on just about every other motorcycle).

I will agree that a lighter system is better in theory . But the question becomes, does it matter? IOW does this weight reduction actually do anything useful from a performance/longevity standpoint?

The thing that bothers me about this particular "upgrade" is that it's the opposite of what any performance engine builder in the world would do. For performance work, an auto engine that comes from the factory with belt drive internals is converted to chain or gear drive. NOBODY converts a chain drive engine to belt drive. Ferrari went to belt drives in their mid-70's v8s and finally, in the mid 90's, went back to chains due to constant issues. At one point they had to come out with service bulletins cutting the factory belt replacement interval in half.

I realize a lot of folks have/like belt drive but there's nothing about it that appeals to me. But hey, we all have our own opinions of what constitutes an "upgrade."

Just when I was thinking about the belt from Norvil. UhOo.

Dave
69S

Belt drive primaries: they are not as "strong" or "reliable" as the stock chain?

Then why would Kenny Cummings change his chain primary over to a belt drive for all out racing?

Would he not want as strong and reliable a primary drive as possible? Or course, so he chose a belt.

Durability? I have had the same belt in my primary since 1998 now, and I do not baby my bike.

A chain in an oil bath WILL throw that lube into the clutch and will in time contaminate the plates, they nee to be
periodically pulled out and cleaned. A belt drive is dry, my clutch plates have never needed cleaning, and my primary does not leak a drop.

A belt primary is an upgrade. Period.

MexicoMike said:

Belt drive: a solution for which there is no problem...

But what the heck, if it wasn't for alleged "upgrades" a lot of folks would be out of business.

Click to expand...

Tell that to all the racers who run them; may want to advise all those like the original poster with oil leaks and stretched chains.

Honestly, just because there's "no problem" doesn't mean something can't be improved. If so, we'd all be riding 12 h.p. motorcycles. No problems there either...

A serious hard lesion I learned with cycles and chain saws. Chains do not stretch the links/pins and sprocket peaks weak and create slack. Lube does not in any way prevent of protect against this by lube-abilty but mainly by flushing out the grinding compound of grime and metal dust and secondarily cooling. If you can lift links out of the valley then that is how high up the chain bears/wear on teeth and % percentage of lift out of valley is % of chain life used up.

Chains are one of the most efficient power trains known. In over powered Ms Peel if the 40 mm belt ain't up to it then back to the robust efficient if heavier chain
and the hassle to seal big hole for outrigger bearing, which i've done before, but must be redone with each removal, ugh.

I can certainly understand the use of the belt drive for racing due to the reduced weight. It would have the effect of a light-weight flywheel, allowing quicker revving on a high performance engine. I am not questioning that value at all (again, even though NO automobile race engines use belt-drive systems unless it's mandated by the sanctioning body that a car use the oem system and it came from the factory with belts.)

My issue is that for the money involved, what does it do for a street Norton commando that makes a useful difference in operation. Fixing a chaincase leak is not much of a reason. And since I have never had an issue with a Norton clutch, I don't see that as anything FOR ME either. It would be interesting to see a dyno pull on a chain commando, followed by a pull after converting to a belt to see if there was any difference. IF there was, then I might have a slightly different view. But as it is, I honestly don't see anything "broken" that a belt drive fixes.

OTOH, I will admit that I have never ridden a belted commando. Maybe if I did, I might see some obvious reason to like it - maybe it's smoother/quieter? Heck, I don't know. I'm certainly willing to change my mind. I have a friend with a CNW Fastback Commando that is belt drive and an interstate that is chain; I should ask him to let me ride the CNW. Both bikes ran in last year's LaCarrera Panamericana though the interstate fractured it's oil tank about midway through.

Modifying the oil tank REALLY IS a genuine upgrade IMO.

I've gone between belt and chain enough to feel the difference and belt is quieter, smoother and more responsive and maybe easier to shift. Its not that apparent until really pressing a Cdo though, so for my money I'm sticking with chain on Trixie for cost and easy parts sourcing on a bike and delightful thrill riding.
On my special I am trying to reduce mass any and everywhere I can get away with so its belt drive, at least to start out with.

Belts can have more internal friction than chain and require more tension
than chain so are not as efficient transmitting power, but not by much.

All belt driven except for the final chain.

Mike, having lived with both systems, I can honestly say that I much prefer the belt primary. The difference on the road is noticeable especially, I find, when I back off with a few revs on board. The belt is much smoother. As for the freeing of the clutch plates, if you have a totally standard Commando clutch setup that doesn't need freeing off for the first ride of the day, then you have an unusual one. It became just another routine part of the starting procedure to pull in the clutch lever and give it a couple of kicks to unstick the plates first thing in the morning. Most sources that I have seen recommend a strip and a clean every once in a while to de-gum the plates. I also fitted Barnett clutch plates at the same time and, despite other input saying that they don't work that well, I have had absolutely no issues with them (with standard steel plates) in some 18,000 miles. I did snap a belt at nearly 110mph but subsequently found that I'd been running it too tight. Actually, it didn't snap but removed most of the teeth. I couldn't get a replacement for three weeks which was a piss off, but I now have a spare hanging in the garage. Whenever I pull the primary cover (yay, no oil to drain or replace!) it just makes it so much easier to get at whatever needs my attention. As I've stated before, when I got this Commando nearly 5 years and nearly 30,000 miles ago my mantra was "maintenance down, reliability up". I think a primary belt helps. I would put it near the top of my list to do to any Commando that came into my possession along with a Tri-Spark ignition (a Godsend), a single Mikuni and something done about the front brake. The rear drum on Commandos is great and despite the things I've heard, consider them to be an excellent, trouble free device. I look at all the answers to the front brake issue and most, while working more than well enough, just don't sit well from a looks point of view. Too modern. I have a resleeved master cylinder with braided line and consider it to be a good setup when used with the rear drum.

Oh yeah, and the Corbin seat. What a terrific thing. Anyway, try a Commando with a belt and see what you think. I do believe, anecdotally, that a belt will add longevity to your gearbox due to lower stresses.

Thanks, I appreciate the response and the detail. Guess I'll have to ask Art to let me ride his CNW Commando.

I don't have any trouble making helpful modifications at all and if belt provides benefits without compromising reliability, I'm fine with that and might consider it. As far as clutch plates sticking - my normal routine has always been to pull in the clutch and push down the kickstart pedal to a bit above the 1/2 way position or thereabouts and kick the bike from there. MAYBE I have sticking clutch plates and just never realized it it since doing that would unstick them. I have always done that since I had my '71 back in the day.

Again, good summary re the belt...making me think about it!

1up3down said:

Belt drive primaries: they are not as "strong" or "reliable" as the stock chain?

Then why would Kenny Cummings change his chain primary over to a belt drive for all out racing?

Would he not want as strong and reliable a primary drive as possible? Or course, so he chose a belt.

Durability? I have had the same belt in my primary since 1998 now, and I do not baby my bike.

A chain in an oil bath WILL throw that lube into the clutch and will in time contaminate the plates, they nee to be
periodically pulled out and cleaned. A belt drive is dry, my clutch plates have never needed cleaning, and my primary does not leak a drop.

A belt primary is an upgrade. Period.

Click to expand...

Then why does the new 961 Commando use an oil bath clutch if dry clutch is better? Mike's comments are real world, not racetrack. IMO...maybe not humble.

I must admit I suffered for years with clutch issues jealously eyeing up the belt drive conversions, but a bit of knowledge is a wonderful a thing, all the old clutch issues are cured pretty easily these days and at a fraction of the cost of a belt drive.
Yes, I still have to break the clutch out at the start of the day, it's not a negative, just one of the many little rituals and part of the charm, but I haven't had to clean the plates off in years.

For the sort of road use most of us do, a belt conversion is entirely unnecessary, if you've got money to burn go for it but it shouldn't be on anyones essential list.

A lot of new owners dip into this site and I get a bit worried that they end up thinking they've made a huge mistake when they find they apparently need to spend the amount the bike cost again in modifications before they can apparently throw a leg over it and ride it.

I rode 40 miles with a loose gearbox once, try that with a belt.