Belt'agedon

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laurentdom said:
Hi Xavier,

Hope it can help: In most of french industrial hardware shops selling belts, pulleys etc... you can have your belt made to order, much cheaper and of as good quality as those got from Norvil, RGM ... and other Norton parts providers.

Yours should be of AT10 profile, which is a standard one. It means that a 980 millimeters long belt has 98 teetht(one per centimeter).

Mine on my Dominator is a AT10 / 27 mm wide.

Back to your problem: too tight /misaligned / rubbing against something?

Bonne chance

Laurent
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Salut Laurent,

Norvil belts are htd profile... And mine is 896mm long , which complicate everything, cause it's quite hard to find !
 
HTD's can be ordered outside of Norton vendors and if ya have some tanny slot room should be able adjust to run 920T count too.
 
I installed the Norvil kit many years ago and it has been trouble free and reliable. I picked it up in person on a trip over 'ome. Les himself told me how to set it up and basically you need the dual adjusters and initially get it to run true without the side plates on the front pulley then install the side plates and all should be good. I'm running 36/72 which alters the gearing slightly requiring a smaller gearbox sprocket.
 
I've checked my local dealers for a 896mm long htd belt, the only available one is a megadyne gold, at 115€ which seems extremely expensive to me... So back to Norvil ! And wait for the adjusters...

I am running 32x70, std sprocket, it's really fine ! ... When belt is not broken...
 
Theres a posability that if you start it up with the Cover Off , youll be able to SEE if its tracking correctly .

Id be heaveing on the G'box mainshaft , to see if excess slack in the output shaft bushings & bearing .
And seeing the clutch center bearings not gone slack . Stateing the obvious . . . but . ./ .

Also after its RUN ( stopped ) the top run is nudged withthe thumb. If its Bar Taut , it may be TIGHT .

Worn Sprockets & a slack chain can have it running / jumping the teeth / slipping . More like gridygraunching - chainsawish . . .
Vastly Slack , the belt'd jumpover the teeth , too .

Agricultural ' belt dressing ' lubes V belts & pulleys . So the run free & dont slip . dunno if its any use there ?

Also , the old foot on the drive chain ( on & off ) , with primary cover off , will show if things are a bit slack in the Trans ( Gear Box Bearings / Case )

Have a goosd glare at the box mounting lugs to cradle while you try this too . If somethings not right , therell be squiggle there , :shock: :(
If its been run loose it couldve chaffed the lug ends / bolt holes . :eek: :shock: :?
 
Being a tad paranoid that this would occur to my newly installed RGM belt drive I left the primary cover off and pulled the sparkplugs to kick over multiple times to observe the belt's happiness and settling-in location on the splines. Plugs back in then a startup with full exposed observation of running-tracking. Cover back on (unvented) and away we go. :D
 
Go back to chain but a Mercedes diesel duplex...job done.

I am bias'd but then I am andychain.
 
Well, the reason for going belty is mainly to reduce stress on gearbox by lightening the clutch drum, it's not for the reliability of a belt drive !

Double adjusters : done !

Here is a picture of my current front pulley setup :

Belt'agedon

As you can see, I don't have room for the standard backplate due to the crankcase bossing, and Norvil said wasn't needed. Is it something I should worry about ?

Cheers

Xavier
 
Xpongebob said:
As you can see, I don't have room for the standard backplate due to the crankcase bossing, and Norvil said wasn't needed. Is it something I should worry about ?
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I think it's very risky not having that plate fitted. It's asking a lot for the belt to stay on the pulley with nothing to prevent it wandering off even with perfect alignment, which is difficult if not impossible to achieve on a Commando. It will inevitable rub on some part of the crankcase or chaincase. Only way I could see it surviving is if the alignment pushes the belt against the other retaining plate but that would be even harder to setup than getting the belt aligned and would wear the plate away. I have the Norvil kit & aligned it as well as I could & it still rubs slightly against the inside retaining plate, to the extent that it started to wear the plate away. The belt survived ok though. I made a new inner retaining plate out of brass sheet & made it the largest diameter I could that would fit inside the alternator mounting bosses. Maybe you could make a thinner one out of something stronger than the original soft aluminium that would fit.

Ian
 
That's interresting Ian, I need to take a tour to my local shop in order to see what can be done, as I don't own a lathe myself.
 
If crank ain't got over .002" run out and levering a bit on clutch basket don't reveal detectable wobble then there is no need of side plates at front though nerve wracking that's how I've tested mine running, after recovery of one that rubbed apart on front plates, but still too chicken to run on road that way.
 
Well, let's imagine my previous setup was okay, that belt moved slowly helped by slack... Nothing got it back on track, so better be safe than sorry !
 
You absolute need side plates on a cog belt drive. They can be one plate on one side of a sprocket, the other plate on the other side of the other sprocket, but some where in the set-up, there must be two. Proper alignment makes minimal use of the side plate, but it MUST be there, or this failure is going to happen. I've built, repaired hundreds of these in industrial applications, seen lots of failures because they were incorrectly serviced.
Whoever told the OP it was OK, was in err.
 
I have had a belt primary for 15 years now and do not have any side plates.

No need, with a left side threaded adjuster the belt runs dead solid true.

Ok, maybe I got lucky when I first set it up, frankly it was pretty easy to get it tracking with no side to side movement.
 
Reading through these posts about belt failures leads me to ask this question!

If and when you have the primary cover off for a wee look see during normal maintenance do you find it dusty with belt dust?

I have been running a belt drive (Norvil Alloy with 2 plates on the crank pulley) on my 73 750 for 2000 miles now and noticed a slight covering of black dust on the inside of the chaincase. The belt was set up without the outer plate on and the engine turned over to check for run off I've got 2 gearbox adjusters and no visible wobble on the clutch drum, belt tension on the top run seems ok (Able to twist though 90degrees).

I'm thinking a certain amount of dust from the belt is inevitable but just wanted to know if others have this too.
 
hobot said:
Do'h
Belt'agedon
Click to expand...
Is that a 30/40 krag round in your mouth of a .303?
 
I'm thinking a certain amount of dust from the belt is inevitable but just wanted to know if others have this too.
Click to expand...

yes, that has been my experience throughout the 15 years in my belt primary

stands to reason it would shed some black powder going around all those times

probably not necessary but I take the primary cover off every couple hundred miles or so to look in there
and make sure all is well while blasting the powder with brake cleaner and wiping it clean

but then I only put on some 1000 miles a year on short little 50 miles loops nowadays

My original belt lasted almost 25,000 miles until I replaced it out of general principle
 
Saw one just like this at the INOA Wyoming rally lays July. Don't see many examples of similar destruction of chains. Primary chains...good.

Belt'agedon


I
 
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