72’ Final drive chain. DID?

worntorn said:
If you think of the tooth profile in 1/8 inch wide increments, a 520 has 2 increments, a 530 has 3.
Consider tooth pressure to be a hypothetical 150 units of pressure ( use any unit)
A 520 sprocket has to bear that pressure on two 1/8" increments, so each increment is under 75 units of tooth pressure.
A 530 sprocket bears the pressure on three 1/8" increments, so each increment is under 50 units of tooth pressure.
75 is 50% greater than 50.

The 530 x ring DID drops right on standard MK3 sprockets, same with a 650ss.
Not sure about other models.

Glen
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It’s a 33.33% reduction when decreasing in size and a 50% increase when increasing in size…
 
worntorn said:
If you think of the tooth profile in 1/8 inch wide increments, a 520 has 2 increments, a 530 has 3.
Consider tooth pressure to be a hypothetical 150 units of pressure ( use any unit)
A 520 sprocket has to bear that pressure on two 1/8" increments, so each increment is under 75 units of tooth pressure.
A 530 sprocket bears the pressure on three 1/8" increments, so each increment is under 50 units of tooth pressure.
75 is 50% greater than 50.

The 530 x ring DID drops right on standard MK3 sprockets, same with a 650ss.
Not sure about other models.

Glen
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Yes, 530 is nominally the same as 10B-1. Yes, any 530 I know of chain fit the sprockets well enough. Anything wider than a standard duty 530 will eat the inner primary and/or gearbox on Commandos through 74. Good to know there's more room on a MKIII - I didn't know that.

Interesting math: apples + oranges does equal fruit :) 2/3 = 67% of the surface area, therefore, lost 33% 50 (lost)/150 (total) = 33.333 lost, not 50.
 
Fast Eddie said:
It’s a 33.33% reduction when decreasing in size and a 50% increase when increasing in size…
Click to expand...
Yes. This results in tooth pressure increasing by 50% when switching from 530 to 520. Took a few minutes to get my head around it.
Hopefully the " increments" description explains it ok.
Another way to look at it is-
For a chain pull resulting in a tooth pressure of 100 pounds per sq inch on a 530, what would the pressure per sq inch be on a 520?
It is 100 pounds per sq inch divided by 66%= 150 psi.

The same result , 50% greater tooth pressure.

Caterpillar learned all of this in the 1930s with track chains on the big new RD8, although not 530 or 520 size!

Glen
 
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My 920 Commando has been running a 520 X Ring DID chain for 10,000 miles now, & gets a jolly good spanking every time I ride it. I've adjusted it twice if my memory is correct. It's the best thing you can fit, unless you actually enjoy adjusting chains, but I prefer riding. To this end I have also converted the 750 Commando, the Atlas, the 612 Big Head Bullet, & also the 750 Lightning I'm currently building.
One of the problems with some owners of Brit bikes is they seem to think it's okay to just change the chain when it's shagged, but that sprockets should last forever. This of course might be because the rears are expensive & the gearbox sprockets are time consuming to change.

Martyn.
 
Matchless said:
My 920 Commando has been running a 520 X Ring DID chain for 10,000 miles now, & gets a jolly good spanking every time I ride it. I've adjusted it twice if my memory is correct. It's the best thing you can fit, unless you actually enjoy adjusting chains, but I prefer riding. To this end I have also converted the 750 Commando, the Atlas, the 612 Big Head Bullet, & also the 750 Lightning I'm currently building.
One of the problems with some owners of Brit bikes is they seem to think it's okay to just change the chain when it's shagged, but that sprockets should last forever. This of course might be because the rears are expensive & the gearbox sprockets are time consuming to change.

Martyn.
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If you wear a chain out, you change your sprockets and chain at the same time? That would be a major job on an oil and chain in primary bike. Or have you found that the 520 X-ring chain does not wear the sprockets out?

I toss the standard 530 chain before it is worn out and replace it. I never run a tight chain, and I always keep them clean and lubed. Neither of the sprockets are worn out on my Norton. I might adjust the chain 3 times before tossing it. Takes about 15 minutes to adjust. So that's 45 minutes of riding time I'll never get back. Doing the 520 chain conversion does sound like a good idea.
 
Matchless said:
My 920 Commando has been running a 520 X Ring DID chain for 10,000 miles now, & gets a jolly good spanking every time I ride it. I've adjusted it twice if my memory is correct. It's the best thing you can fit, unless you actually enjoy adjusting chains, but I prefer riding. To this end I have also converted the 750 Commando, the Atlas, the 612 Big Head Bullet, & also the 750 Lightning I'm currently building.
One of the problems with some owners of Brit bikes is they seem to think it's okay to just change the chain when it's shagged, but that sprockets should last forever. This of course might be because the rears are expensive & the gearbox sprockets are time consuming to change.

Martyn.
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I agree, the sealed chains are great. Now that the new narrow profile 530 sealed chains are here I believe we are better off with 530 than 520, if the 530x ring just drops on. Those 530 cast iron rear sprockets last a long, long time, probably 50,000 miles or so. Enough to wear out a couple of good xring chains.
I've been getting about 20,000 miles on the x ring chains, 520 or 530 no difference there. It's the seals that finally go on those.
Glen
 
If narrow 530 sealed chains are wider than the standard 530HD chains, I'd have trouble with a P11.

I'm not sure if P11 chain fit is relevant here, but last time I looked it had a Norton badge on the tank. ;)
 
In my my opinion, it’s the chain wear and stretch that goes out of sinc with the sprocket teeth that fecks the sprockets, the 520 xring lasts a long time before it requires any adjustment after the initial adjustment , after 3 adjustments ditch chain and replace,
This way you can get 2 chains to one set of sprockets,
I also use a scott oiler

Works for me.
 
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In Vincent world we have been getting just 10,000 miles out of the 520 sprockets and 20,000 from the sealed 520 chain.
We went 520 as the old style 530 o ring was just too wide to fit.
The new vx530 drops right on.
Currently testing that but it looks good, the sprockets might run a lot further than 20,000 miles.

Cast iron Norton sprockets last really well. 520 proved too narrow for the mighty 1963 650ss however. That's why Norton changed to 530. I can't see why anything would have changed there, except that most bikes don't cover the miles that a new 650ss might have seen in 1962.

Glen
 
Norton Commando rear sprockets are cast steel not cast iron unless you buy an Indian knock off.
 
I ended up ordering from Dime City Cycles in Tampa. Right around the corner from me.
 
To all those saying a DID 530 X-Ring chains work on a Commando without hitting the gearbox or inner primary, please state the ACTAUL DID or other part/model you are using and the Commando model. I am aware of DID 530VX3 which is 0.931" overall width for the chain itself and more for the master link. AFAIK, there is no such thing as vx530 530vx or anything close to 530VX3 that is narrower than 530VX3. See: https://didchain.com/wp-content/uploads/2020/02/2020-Chain-Spec-Chart.pdf

Notice that a 520VX3 is 0.736 - the 10B-1 chain originally delivered on the Commando was 18.8mm (0.740") wide for the chain itself and 21.3mm (0.839") the master link.

See: https://www.renold.com/media/228840/renold-brand-chain-tables.pdf

I would love to use 530 X-Ring chains - but I've never found one that comes close to working hence the conversion to 520.
 
See the photo in post 22.
Labelled on the box 530vx or VX530 depending on how you want to read it.
Pin length on that chain is .919", according to DID. This chain was recently discontinued, however there is lots of it around on eBay etc.
The new product is 530vx3 which has a slightly longer pin length at .931"

As stated, this drops on a MK3 and also a 1968 650ss. Actually the chain I fitted on the MK3 without mods is a very early DID x ring, almost 1 inch in width.
Using rivetted Masterlinks in all cases.
Concours and Chris have fitted DID 530 xring chain to earlier bikes. Chris says he does not use a chain guard. That might be by choice
It appears that Concours does have the chain guard fitted with the 530 vx chain.
The chain guards have plenty of clearance on the MK3 and 650ss.


Glen
 
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Coolhands said:
I ended up ordering from Dime City Cycles in Tampa. Right around the corner from me.
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Being close to you is why I mentioned Dime City Cycles. Maybe that was a mistake. I have only installed one of the chains they sell. It didn't stretch much initially. However, it has stretched enough to adjust a little after 370 miles. Adjusting a chain is not a major maintenance task. I had to adjust and oil o-ring chains on the big HP bikes I owned. Nothing magical about them or unusual to have to adjust a chain.

The master link on a 530HD chain scraping the inner primary issue is real, so sorry about that. My inner primary was already skimmed by a 530HD master link. So they fit my model now. If you bought an HD chain and can exchange a 530HD chain for a standard 530 chain until you can get whatever it is the seasoned Commando owners think is the ticket to a happy motorcycling life, you might not have any problems or have to come up with a workaround until the better chain solution arrives.

I find my Norton to be hard on chains in general. Not because of a design flaw, but because of the owner's riding style. It is very difficult not to use that low end grunt frequently.
 
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kommando said:
Norton Commando rear sprockets are cast steel not cast iron unless you buy an Indian knock off.
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Vincent tried cast steel brake drums for 1 year and the braking was horrible. They went back to cast iron.
Norton brake drums seem to offer decent braking, so I assumed they are cast iron, not cast steel.
After reading your post I checked with RGM. Their Norton drums/sprockets are made in the UK and are cast iron. Cast iron does have wonderful wear properties, even though it is relatively soft.
Glen
 
If a slimmer sealed 530 chain is needed for your application, RK makes a " classic" x ring that is intended to be dropped right on old bikes which have tight clearances at the gearbox.
I believe that one is .870 pin length. I have posted about it in the past.

www.jim-allan.com

RK 530 UWV Silver Chain x 100

RK530 UWV Classic bike sealed chain - silver
www.jim-allan.com www.jim-allan.com

My standard unsealed 530 spring type spare masterlinks measured .860 and .870"

Glen
 
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