New Belt Drive

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Jerry Doe

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Hello all,

I fitted my new belt drive. Used a new clutch drum, crank pulley and belt. G/B main shaft was new 5000 miles ago. I have the belt with 1 inch total up and down. Now I have never run mt bike with the primary cover off until now. I ran it to make sure belt is nice and true, but noticed my clutch has a wobble. Your thoughts:
Click here for movie: http://www.jerrydoe.com/beltDrive/belt_cold.MOV

http://www.jerrydoe.com/beltDrive/belt_cold1.MOV
http://www.jerrydoe.com/beltDrive/belt_cold2.MOV

Any one else seen this while running their bike with cover off? Is it normal?

Cheers--Jerry
 
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Mine wobbles a bit too. Never seen a straight mainshaft yet. Doesn't seem to affect anything. Jim
 
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Mine wobbles the same. I believe this to be quite normal. I have a RGM unit but I don't think it has anything to do with belt or chain drives.
Don't ya love the sound of the clutch when pulled in?
 
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Hi Jerry,
I'll have to second "comnoz's" and "pvisseriii's" assertion that clutch basket wobble is normal as that was my experience too. I knew it wasn't a bearing because without the plates installed I could hold the basket from rotating and rotate the clutch center with the other hand and see the basket wobble. The only thing that would do that is a curved mainshaft. I wasn't comfortable with it that way so I pulled the mainshaft and with a hydraulic press, hardwood blocks, "V" blocks, a dial indicator, and a great deal of patients I trued that shaft to Zero deflection. After reinstalling the straightened shaft the basket still wobbled somewhat, go figure.

GB
 
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I think it's from play in the clutch bearing. My primary cover is off and I just went outside and could wiggle it by hand.
 
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It seem I heard or read some where the if it didn't wobble a little, something could be wrong. I have not known a clutch basket NOT to wobble. Go Ride!
 

Jerry Doe

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Those that have fitted this RGM drive- Question:

took it to bits to inspect and I noticed my front pulley was loose on the crank like I had spacers wrong. In my case I have: pulley with plate on the inside, followed by standard spacer, then plate with chamferred edge in, then key then rotor. Is this correct?

Cheers
 
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This is the order of installation, Hub (attached plate inboard), spacer, outer plate (chamfer towards the belt), then rotor.
It also seemed to me that it didn't really lock on to the taper like I thought it should but I have no problem with it. I also recall having to get narrow spacers for the stator to line up over the magnets better.
 

Jerry Doe

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I just took it to bits and realized I put the wrong crank spacer and front pulley was loose. I used my original by mistake. There is another one that comes with the kit with an inner cut away that goes cut away inwards. This allows the pulley to be tight. Mine was loose as I used the original without the cut away. Now all is good and torqued to 80 lbs-- going for a test ride

cheers
 

nortonspeed

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Jerry Doe said:
Any one else seen this while running their bike with cover off? Is it normal?

It may be normal to your standard, it is certainly not to mine! It should run straight and if not something is wrong!
I have run belt drives for over 20 years (street and race) and they run straight without a wobble.
 
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nortonspeed said:
Jerry Doe said:
Any one else seen this while running their bike with cover off? Is it normal?

It may be normal to your standard, it is certainly not to mine! It should run straight and if not something is wrong!
I have run belt drives for over 20 years (street and race) and they run straight without a wobble.
Normal? Maybe not. Common? Perhaps.
I don't think most Norton gearboxes have bent mainshafts. I think it is more along the line of how it was engineered in the first place. This big ol basket hanging out the end with one roller bearing handling the duties of the hole clutch operation.
This seem to be going in the same direction as oil leaks topics. Whats normal, whats common, what exceptable?
Let's go ridin!
 
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nortonspeed said:
Jerry Doe said:
Any one else seen this while running their bike with cover off? Is it normal?

It may be normal to your standard, it is certainly not to mine! It should run straight and if not something is wrong!
I have run belt drives for over 20 years (street and race) and they run straight without a wobble.


Thats correct. It's not "right" . I tried to get mine to run true years ago and traced the problem to a slighly crooked mainshaft. So I ordered a new one and it was crooked too. I exchanged it and got one that was worse. So I got one from a different source who said their's were straight. It wasn't . I took the time to straighten and recut the snap ring groove on my bike to get it to run straight. Then I broke the trans and mainshaft and the replacement was not quite straight again. Since then I have installed dozens of belt drives and I don't recall seeing one that run perfectly true but I have not seen any problems because of it. Jim
 
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My life became a lot less complicated (and expensive) when I finally stopped expecting to find perfect components in a Commando when dismantling. After years of trying to achieve perfection within my limited abilities, I developed the ability to say "It's not going to break and a new one will be just the same within a few thousand miles"

How long does one of those long barely supported mainshafts with a big heavy clutch on stay straight ? One hard take-off ? One time hard down the box ?

Commando mainshafts are like their pushrods, crankshafts and exhaust systems. It's possible to get them straight for a photo shoot but in use they're all flailing around like a Dervish with Saint Vitus' dance. :)
 

nortonspeed

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comnoz said:
Thats correct. It's not "right" . I tried to get mine to run true years ago and traced the problem to a slighly crooked mainshaft. So I ordered a new one and it was crooked too. I exchanged it and got one that was worse. So I got one from a different source who said their's were straight. It wasn't . I took the time to straighten and recut the snap ring groove on my bike to get it to run straight. Then I broke the trans and mainshaft and the replacement was not quite straight again. Since then I have installed dozens of belt drives and I don't recall seeing one that run perfectly true but I have not seen any problems because of it. Jim

Try a Maney belt-kit (preferably on a Quaife mainshaft) and you will see it running straight for sure.
But indeed Let's go ridin!
 

Jerry Doe

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Well good and bad news came out of my test ride.

Good:The clutch and belt drive are good-- no vibration etc.

Bad news: My alternator burned up (probably cause I had clearance wrong). Also just looked closely and discovered a crack on inner primary. This crack is leaking oil from the crank through bolt threads and out through crack. When I saw oil it had to be from there. This oil leak was the reason for the belt drive in the first place. Damn nortons, wish I saw the crack first, then would have not got the belt drive :evil: -- Oh well gonna ride my friends Kawasaki tomorrow instead.

:( crack: http://www.jerrydoe.com/beltDrive/100_3405.JPG
:( Alternator: http://www.jerrydoe.com/beltDrive/100_3404.JPG
Cheers- Jerry
 
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Oh Damn, Jerry. I can well imagine exactly what you thought when you pulled the cover off and saw that. :shock:

I think that you're right to take a day away from it.

At least we can get the parts.
 

Jerry Doe

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The belt seems ok still and I have another primary inner. Just need an Alternator and Rotor. I am going to take it all to bits (of course) and get a dial guage on the mainshaft. Now it is beer/ebay time,

Cheers
 
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nortonspeed said:
comnoz said:
Thats correct. It's not "right" . I tried to get mine to run true years ago and traced the problem to a slighly crooked mainshaft. So I ordered a new one and it was crooked too. I exchanged it and got one that was worse. So I got one from a different source who said their's were straight. It wasn't . I took the time to straighten and recut the snap ring groove on my bike to get it to run straight. Then I broke the trans and mainshaft and the replacement was not quite straight again. Since then I have installed dozens of belt drives and I don't recall seeing one that run perfectly true but I have not seen any problems because of it. Jim

Try a Maney belt-kit (preferably on a Quaife mainshaft) and you will see it running straight for sure.
But indeed Let's go ridin!

I've used a Maney belt drive. Nice stuff. I've not seen problems with the clutch hub itself being crooked although it's definatley possible. I usually cheap out and go for the RGM although I wouldn't if I didn't have a lathe to iron out any little fitting problems they commonly have.
No doubt a Quaif mainshaft would cure a mainshaft problem. The stock ones I have checked appear to have warped from the heat treatment.

I am ready for that ride. I had a 15 hundred mile trip planned for next week but work is threatening to toss a wrench in the works. Jim
 

Hortons Norton

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Jerry be sure the new inner cover is shimmed out to the proper spec. Cracks in that location look to be caused by tightening the center nut without having the proper shims behind the cover, I've seen a few covers like this. The previous owner must have left the shim out or had the wrong one in there.
 
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