G: Gearbox (Twin) ‘O’ Ring Chains

johncrispin

Well Known and Active Forum User
VOC Member
Just wanted to ask members how they have got on with the thinned sprockets and o ring chain set up.
I know one or two who seem pleased overall. I need to change my sprockets before setting off to the rally in June
so would welcome any observations either pm or on this forum
 

stumpy lord

Well Known and Active Forum User
Non-VOC Member
Just wanted to ask members how they have got on with the thinned sprockets and o ring chain set up.
I know one or two who seem pleased overall. I need to change my sprockets before setting off to the rally in June
so would welcome any observations either pm or on this forum
works O.K. on my twin.
 

Robert Watson

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VOC Member
I have run 520 oring chain and very hard SAE 8620 case hardened sprockets for a number of year now. All of that setup will run 20,000 miles, and I am not easy on it as some will attest. I don't use a chain oiler but do carry a small spray can when travelling and give it a lubrication at the end of a long day or if travelling in nasty weather.

One of the absolute best changes you can make if you want longevity.

I had some rear sprockets made but the price on a second batch became prohibitive but am working on a new plan that might bear fruit in the next few weeks.

I have done front sprockets by "re ringing" good used ones (and even a couple of new ones) with the hard rings.

Robert
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Monkeypants

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Non-VOC Member
I've used the sealed chain on the OZ Rapide for quite awhile now. I'm sure it was Robert who first informed me of the advantages.
I wouldn't want to go back to the unsealed. I have worn out one of Robert's reconditioned front sprockets and am now working on the second, which still looks very good. That's a lot of miles covered tho. I've done 55,000 with that bike and most of it was with the 520 sealed setup in place.
The chains have lasted an easy 20,000 miles.
On rear sprockets, we used some anodized alloy ones that weren't horrible but did disappear quickly after the anodized portion wore through at about ten thousand miles.
At present I have a club steel 520 on the back, but it hasn't gone far yet, still as new.

It's too bad we can't run a full 530 sealed setup on there, or can we?
I run 530 sealed on the Commando, it fits right on the late model bikes. It just carves out a tiny bit of alloy on first time thru. At twelve thousand miles on the sprockets and chain there just isn't any visible wear. I think this setup could see me out for that bike, which doesn't do huge mileages, maybe 2500 per year on average.

That chain is a DID VM50 or 530 and it measures .970" for pin width.
The VM series is no longer available, it's been replaced by the stronger and narrower VX series at .917" pin width.
The unsealed 530 chain on the back up Rapide is .870"
So now we are only talking about 47 thou total extra width for a sealed x ring 530 vs unsealed. Split in half thats just 23 thou greater width from sprocket edge than an unsealed 530.
Might be able to scrape a little alloy out for that much extra clearance?
Presumably the .870 unsealed 530 has a wee bit of spare clearance already.
The needed extra clearance may already have been created unintentionally by 70 years of use!

Glen
 

johncrispin

Well Known and Active Forum User
VOC Member
Glen,
Thanks. Interesting observation about the 530 chain, worth doing surely for the small amount of material it might remove, has anyone else made this mod ?
Robert,
Thanks. Can you let me know please if and when your new scheme comes to fruition , looks like it is a positive move all round.

I have run 520 oring chain and very hard SAE 8620 case hardened sprockets for a number of year now. All of that setup will run 20,000 miles, and I am not easy on it as some will attest. I don't use a chain oiler but do carry a small spray can when travelling and give it a lubrication at the end of a long day or if travelling in nasty weather.

One of the absolute best changes you can make if you want longevity.

I had some rear sprockets made but the price on a second batch became prohibitive but am working on a new plan that might bear fruit in the next few weeks.

I have done front sprockets by "re ringing" good used ones (and even a couple of new ones) with the hard rings.

Robert
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Robert Watson

Well Known and Active Forum User
VOC Member
I sent quite a big selection of the hard ring front sprocket to the UK a few years ago so not sure what he has left in them, so you might get that over there (I have also done some ones for Comets, AMC, and other boxes in 520 and 530 in various tooth sizes)

If I can get some hard rears at a reasonable price I'll let you know.
 

Monkeypants

Well Known and Active Forum User
Non-VOC Member
If someone has a bike with G50 plate removed perhaps they could measure the clearances.
Just can't remember where the old wide 530 sealed chain would have fouled, probably on the gearbox housing, G50 plate or both.
If I decide to hang onto and use this 49 c Rapide ( the backup bike) I might order a narrow VX 530 for it and see if it can be made to work.
It stands to reason that wider sprockets in any given material would have a little easier time of it.
The 525 VX is about ten thou narrower than unsealed Renold 530, so it would clear the gearbox and g50 without drama.
This would require thinning the stock 530 sprockets by 1/16".

Glen
 
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vibrac

Well Known and Active Forum User
VOC Member
For once I feel left behind in this technical conversation to me I have raced and ridden on two chains 5/8 X 3/8 road and 5/8X 1/4 for the racers all this 530 and 520 has me lost I surmise their sprockets must be thinner or do the link distances vary from 5/8"? I guess these metric interlopers are the reason I have to take a link with me when I try and get a new spring link where as in the golden years I just had to mumble 3/8X 5/8.
I guess the other reason for my ignorance is that all my modern transports seem to use shafts....
Please someone help me at starter level
 
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