Sprocket Wear

Niagara850 · May 24, 2012

When is it time to replace spockets? I have the primary open to replace the clutch hub and decided to look at the the counter (front drive) sprocket.
Here is what I have, the teeth appear to have wear on the left side.

[ATTACH=full]87759[/ATTACH] [url=ht...tos/52577093@N03/7263798546/]Front Sprocket 1 by niagaraz, on Flickr[/url]

Niagara850 · May 24, 2012

Hear is another pic, apparently I can only post one at a time. 21T sprocket

[ATTACH=full]87760[/ATTACH] [url=ht...tos/52577093@N03/7263796128/]Front Sprocket 2 by niagaraz, on Flickr[/url]

pete.v · May 24, 2012

It shows some wear but good for another season. It's a shame you don't have one handy at the moment while you have it all exposed.

You might want to treat that chain to a soaking though.

1up3down · May 24, 2012

sprockets are pretty cheap, aren't they?

Why not put a new one on now while you got it apart and go another ten years not worrying about it?

Whitworth Ranch · May 24, 2012

Check countershaft sprocket alignment with the rear sprocket. That is not typical wear and indicates a possible alignment issue.

By all means replace it. They are so cheap. Then check that all lines up before you button it back together.

Hobot · May 24, 2012

Its and alginment issue either by rear drum or the tranny seleeve bush clutch basket wobble, before or after you acquired it. Current condition is fine for sprocket function as the teeth are not fanned over or missing, but the chain might be wearing a bit more but not by the stretcheroo loading as can be told by the thin 520 size teeth still sticking or and standing proud.

For closer look to note lack of side wear tick here, two of these are milled back for bad idea to me 520 chain
http://rides.webshots.com/photo/2989639 ... 1179dOSLAC

mikegray660 · May 24, 2012

Whitworth Ranch said:
Check countershaft sprocket alignment with the rear sprocket. That is not typical wear and indicates a possible alignment issue.

By all means replace it. They are so cheap. Then check that all lines up before you button it back together.

+1
yikes :shock: def. check alignment & replace the chain too I'd check rear sprocket too if worn maybe time for entire 520 upgrade - better to do it now while its apart + its an easy repair

Niagara850 · May 24, 2012

You guys are confirming what I'm thinking, replace. It would seem the back sprocket was angled to left to get that wear pattern. I've only put a couple thousand miles on it myself . I'm working my way back through the drive train fixing as I go. I need a new chain, it fails the pull test on the back sprocket. I need to take a closer look at the back sprocket. I plan to do the back brakes so that's coming apart too.

What is the 520 upgrade, besides putting a 520 o ring chain, are the sprockets different too?

mikegray660 · May 24, 2012

Niagara850 said:
You guys are confirming what I'm thinking, replace. It would seem the back sprocket was angled to left to get that wear pattern. I've only put a couple thousand miles on it myself . I'm working my way back through the drive train fixing as I go. I need a new chain, it fails the pull test on the back sprocket. I need to take a closer look at the back sprocket. I plan to do the back brakes so that's coming apart too.

What is the 520 upgrade, besides putting a 520 o ring chain, are the sprockets different too?

replace and double check its straight! yes - machined down a bit to keep chain from hitting inner primary - if you have to replace your rear drum not a bad idea to switch over- available at most "norton" suppliers (or if you know a machinist pal can be done easily)

CanukNortonNut · May 24, 2012

Niagara850 said:
You guys are confirming what I'm thinking, replace. It would seem the back sprocket was angled to left to get that wear pattern. I've only put a couple thousand miles on it myself . I'm working my way back through the drive train fixing as I go. I need a new chain, it fails the pull test on the back sprocket. I need to take a closer look at the back sprocket. I plan to do the back brakes so that's coming apart too.

What is the 520 upgrade, besides putting a 520 o ring chain, are the sprockets different too?

Niagara
The 530 chain is made to fit a 3/8” sprocket width.
The 520 is for 1/4" wide sprocket like the atlas(I believe….correct me if I am wrong). Like MikeGray stated you can either buy the parts from a supplier or if you have a machinist buddy you can do it yourself. Rear drum sprocket needs to be turned down as well. Milled on the outboard side.
I like the 520 x rings chains DID manufacture. They handle more power than the commando will ever produce.
You don't have too much hook on the sprocket so if the other side is ok then lathe this side down. How are the drum sprocket teeth looking?
Clubman racing carries the kit as well as Old Brits.
But I would sort out your alignment issues first. :?
Cheers. Tom.

CNN

Hobot · May 24, 2012

Its a real bother to almost impossible to use straight edge or eye to get good alignment and can't use big long tools for a flat away from home. Just stick a finger between tire and swing arm and diddle equal-ish and nip up, recheck, re-do then ride it. Go ahead and try to use a device for this and let us know how ya did it. I gave up on two types of cycles converted to 520 chain d/t the accelerated tooth decay shown in my photo above. Does similar to drum teeth till just nubbings making whirl nosies going no where fast. I love X-rings just no more 520 narrow teeth for me.

Torontonian · May 24, 2012

Replacing all 3 is the best and most expensive way as fitting new to old quickly matches up with old wear pattern. Yes , check alignment .

rpatton · May 24, 2012

A 3 foot piece if 1/2" drill rod works to check the alignment. $25 @online metals.

BA10BOON · May 25, 2012

mikegray660 said:
Whitworth Ranch said:

Check countershaft sprocket alignment with the rear sprocket. That is not typical wear and indicates a possible alignment issue.

By all means replace it. They are so cheap. Then check that all lines up before you button it back together.

Click to expand...

+1
yikes :shock: def. check alignment & replace the chain too I'd check rear sprocket too if worn maybe time for entire 520 upgrade - better to do it now while its apart + its an easy repair

+2, That's not typical wear to me, and i wouldn't personally like to run another season like that. Alignment looks the likely culprit. I'd change the chain and sprockets. Really not that expensive, and safety critical.

Dances with Shrapnel · May 25, 2012

CanukNortonNut said:
.....if you have a machinist buddy you can do it yourself..........the other side is ok then lathe this side down.

The countershaft sprocket is hardened so it will take some extra measures to shave it down from 530 to 520; either special cutting tools or grinding. Although I have done this for Vintage race applications, this was done "in-house"only to get the chain offset I wanted. For street applications I would go with off the shelf. This will start you off with a nice fresh tooth profile.

As stated elsewhere above, bin the old chain and replace the rear sprocket if questionable.

O-ring chain is the cats pajamas but I don't know about potential clearance issues, other may be able to elaborate on that. At the risk of stating the obvious, with o-ring chain, the lubrication and maintenance is a but different than OEM chain.

Hobot · May 25, 2012

To convert to ** .240" ** wide teeth "Not" .250" , just buy an Atlas 520 sprocket and have shop mill the DS of teeth off the drum. Most can fit 530 X-ring but not "slightly wider and way stiffer O-ring", w/o clearance issues that matter, some clear completely others chew a bit of a non issue notch in gb or primary case before running silent. Plan for spare teeth on hand if using all the Torque on tap regularly.

Dances with Shrapnel · May 25, 2012

If you do opt for a 520 chain (which is a decent upgrade) make sure you get the chain alignment right; especially if you set out to cut down a 530 sprocket. Know where you need to be with all of this before cutting and replacing.

Hobot · May 25, 2012

Pray tell how the alignment is an issue or how its dealt with please.

Dances with Shrapnel · May 25, 2012

hobot said:
Pray tell how the alignment is an issue or how its dealt with please.

If I need to explain, then you have no business fooling around with Nortons or motorcycles in general but, once again like so many times before, I will be giving hobot the benefit of the doubt..........

Per your querie regarding how the (sprocket alignment is an issue), remember the beginning of this thread; I direct your attention to the following sprocket picture.

That is how alignment is an issue.

If this wear is evident on the current bike then there is an alignement issue. Changing to 520 sprockets alone will not resolve this.

If one is going to trim down a hardened counter sprocket they better know which side or sides need to be trimmed. If one sladder arse puts something together like a dagwood sandwich they will end up with cr*p.

Those interested can contact Kenny Cummings of NYCNorton.com to see where he sourced his laser pointer used for sprocket alignments. It clips on to either the counter sprocket of rear sprocket and provides laser line of sight reference; a pretty slick tool. You can see it in action in his blog.

Dances with Shrapnel · May 25, 2012

Thank you ludwig for clarifying my point.

See the NYCNorton.com link for the laser alignment tool.

broken link removed

There are three degrees of sprocket alignment, two of which pertain to main shaft/rear axle parallelism. The third is sprocket offset along the shaft axis.

Sprocket Wear

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