Shims Improve Clutch

The recent conversion to an 850 clutch had left my poor old 1972 750 Norton with very heavy effort needed and engagement right on the bar with no free play at all. A short ride ended when the clutch was dragging so badly that it became difficult to find neutral and the bike wanted to nudge gently forward like an old Model T.

Old Brits sells ground shims to bring the Clutch stack right out to the end of the splines and many good things were said about these shims. Old Brits have a great deal where they sell five plates of varying thickness and allow you to return the unused plates for refund. I ordered this set along with a new Venhill clutch cable which Old Brits thought to be teflon lined.

The parts arrived Friday in the UPS and the .078 Barnett plate proved to be a perfect fit. The clutch is now much lighter and has the overcenter feel that many Commandos have. Adjustability has returned and the clutch could be set to engage more toward the middle of its travel with plenty of free play.

A quick test ride confirmed that all is working well. It completely disengages, is smooth and progressive with no slip and neutral is easy to find. I can't say it is light compared to other motorbikes, but it is as good as any Commando I have tried recently and I'm very pleased with it. We never bothered to install the new cable, now that can wait until the next time the gas tank has to come off.

Vintage Paul

Real Nortoneers keep the whole set on hand but glad you re-joined those that like the fine factory feel of fully fettered clutch lever action. Remember it for when its starts to decay eventually.

hobot said:

Real Nortoneers keep the whole set on hand but glad you re-joined those that like the fine factory feel of fully fettered clutch lever action. Remember it for when its starts to decay eventually.

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How did they adjust the stack at the factory? Did they have plates of different thicknesses or were the factory plates all so uniform that this just wasn't an issue?

Vintage Paul

hudson29 said:

A quick test ride confirmed that all is working well. It completely disengages, is smooth and progressive with no slip and neutral is easy to find. I can't say it is light compared to other motorbikes, but it is as good as any Commando I have tried recently and I'm very pleased with it. We never bothered to install the new cable, now that can wait until the next time the gas tank has to come off.

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When you fit the new cable I suggest that you also try to re-route it to remove that bend close to the clutch lever?

Your story doesn't surprise me, but I'm glad it worked out, I eventually want to do that with my clutch, but right now it's perfectly acceptable, but I don't find the clutch hard to pull, but then I don't have anything with which to compare it. Yes, L.A.B. is correct, you should route the cable with a better bend than is shown, here is mine, it arches over the speedo and down along the central tube, you need to make all the cables route with the least bend as possible.



Dave
69S

I prefer to replace or re-route, or leave nice looking bar following path as is, rather than have cable plus road and dead bug body grit and acids marring the clock bezel. I shift clocks so the cables enter the straightest which pretty much works out with clock mounts aimed essentially parallel and straight ahead. More tricky and effective clutch cable aiming is how enters the gearbox. Some lazy Nortoneers tend to route 2 cables next to each other for the longer hauls into the unknowns.

The cable entering the gearbox should be as straight as possible to reduce drag and minimize snapping of cable at the bend.
I know on my bike it was difficult but I believe I did get it straighter than yours shows.

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How did they adjust the stack at the factory? Did they have plates of different thicknesses or were the factory plates all so uniform that this just wasn't an issue?

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HA, just sent em out as is, a half completed kit to be nursed to health by dealers and us.

rx - what's up with the throttle cable?

hobot - your avatar is flaked (it's showing the dreaded red "X").

hobot said:

HA, just sent em out as is, a half completed kit to be nursed to health by dealers and us.

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So true, except that most dealers just pushed them out the door as fast as they could, into hands of naive and unsuspecting owners who then wondered why their bikes kept falling apart. That's why you see so many Commandos even today with only 9000 miles on the clock.

(or maybe it's because the speedo has been rebuilt/reset a time or two...)

I had a profound revalation after installing a set of Barnet friction plates in my 850. The clutch pull was noticeably lighter. Upon further investigation I discovered that the new plates were exactly .125" thick each and my old bronze plates had worn to .123". So 5 plates meant a total difference in .010" stackup and was noticeable in clutch effort.

I did the Old Britts plates and ended up with a .065" shim. With a Venhill cable my clutch is truely wonderful.

How did they adjust the stack at the factory? Did they have plates of different thicknesses or were the factory plates all so uniform that this just wasn't an issue?

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They routed the cable carefully and it was what it was. I recall the clutch being a bear to pull in from the day I rode the bike from the dealer's lot.

You guys certainly have sharp eyes! That bend at the lever end was a recent addition and happened accidentally after trying to lube the cable. My old lube tool quit sealing and squirted lube everywhere but down the cable. I bought a new two screw job & it did just the same. The cable still need lube & I'll fix the routing after doing that.

The gearbox end is another story. This was the best I could figure when I installed the cable 15 years ago. I'll have to see if it might have a better run elsewhere.

Vintage Paul

I have also heard that you can use an earlier style clutch release arm, This has a little different profile that also helps. Don't remember where I heard this but I do have one in the parts supply that I plan on putting in at some point.

Hortons Norton said:

I have also heard that you can use an earlier style clutch release arm, This has a little different profile that also helps. Don't remember where I heard this but I do have one in the parts supply that I plan on putting in at some point.

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What you may be referring to is the Atlas release arm.

swooshdave said:

Hortons Norton said:

I have also heard that you can use an earlier style clutch release arm, This has a little different profile that also helps. Don't remember where I heard this but I do have one in the parts supply that I plan on putting in at some point.

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What you may be referring to is the Atlas release arm.

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Didn't Dynodave have an article on that at Atlantic green? I remember he was talking about those different levers recently.

Dave
69S

Hortons Norton said:

I have also heard that you can use an earlier style clutch release arm, This has a little different profile that also helps. Don't remember where I heard this but I do have one in the parts supply that I plan on putting in at some point.

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Seems to me I saw something on the Norton Owner's Club site about this. I took the Norton out for another ride yesterday evening and the clutch was soooo good I soon forgot about it and was able to pay attention to other things like vibration periods that were less urgent. Things can only get better with a properly lubed and routed cable.

I took the Commando out through some sweepers at something close to 70 mph and found it to be as stable and confidence inspiring at these speeds as it is at low speeds. When I last rode it in 1998, it had a squirrely feel and a vicious speed wobble. I retired the bike after it tried to unhorse me on the Santa Ana Freeway one Sunday afternoon. With the repair of the rear hub that is all gone.

I was feeling pretty pleased with things as I headed back to the barn when the motor started misfiring. I opened the reserve tap hoping I had just run low of fuel but this did not help. The motor stopped dead and I coasted most of the way back to the shop. I did have to push the last 500 feet but that did not wipe the smile from my face. The joy of riding this Commando is just too intense to allow a little thing like being turned into a pedestrian to spoil it!

On getting back, the ignition tell-tale light was found to be off and then the lights quit working too. The whole electrical system is dead. At least this issue should be easy to trace!

Vintage Paul

If your ignition switch is old, that may be suspect. Mine did the same and I took it apart cleaned the grunge off the contacts installed new de-ox put it back together and it's fine now. But my switch is simple, only 2 positions with a wire to the ignition and one to the lights. Grounds can do it too.

Dave
69S

DogT said:

If your ignition switch is old, that may be suspect. Mine did the same and I took it apart cleaned the grunge off the contacts installed new de-ox put it back together and it's fine now. But my switch is simple, only 2 positions with a wire to the ignition and one to the lights. Grounds can do it too.

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I have the same switch you do, NOS but only used for a bit over 700 miles. I'll certainly check the switch along with other things. Perhaps I wasn't as careful as I should have been with something.

Vintage Paul