Uneven chain wear!

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keithmac

Guru
It's good practice on Motorcycle chains to find the tightest spot and adjust at that point.

See it quite often on well used chains.

Obviously there's a point where the slack spots are too slack, then it's replacement time..
 

andrew_s

Legendary Member
Location
Gloucester
This topic is from 2018, but...

One cause of apparent uneven chain wear is that the outer links don't wear at all, so if you measure such that there's one more inner link than outer, you'll get more wear than if you measure one more outer than inner.
You can avoid this by always measuring an even number of links. You'd hope that all commercial wear gauges did so, but using a ruler or a vernier caliper might not.
 

CharleyFarley

Senior Member
Location
Japan
This topic is from 2018, but...

One cause of apparent uneven chain wear is that the outer links don't wear at all, so if you measure such that there's one more inner link than outer, you'll get more wear than if you measure one more outer than inner.
You can avoid this by always measuring an even number of links. You'd hope that all commercial wear gauges did so, but using a ruler or a vernier caliper might not.

Yes, I realized it was an old thread but I understand it's preferred to continue it rather than start another thread on the same subject.

Yesterday, after finding the uneven wear I searched 'Uneven chain wear' and came across a few things, one of them being the 2018 thread. Elsewhere I read that the way the teeth are ground on the side can cause it. I don't see why that is. I can't find that website which explained it, now.

I just now went and checked the chain, again, using the Park tool and a Pedro's checker. Pedro's indicates it's okay but I didn't check it in several places. The Park tool has two pins, one of which goes between the inner plates, and the other pin between the outer plates. In the past I haven't checked it in more than one place, which is why it surprised me, yesterday.

The sprockets look good. Anyway, I've ordered a new chain. Even if some parts of the chain are good, it's still not a good chain.

Incidentally, I replaced the chain on my cruiser about a year ago. I got the new chain from a LBS, and it was in a blue Shimano pack. After riding a 100 miles I did the usual service and found the chain was worn out. The bike shop has been in business for at least 40 years and I don't believe they'd sell me a used chain, so I tend to think that somebody had bought a new chain, put it on their bike, put the old chain in the blue Shimano pack and took it back for a refund. That's pretty low. I didn't tell the bike shop about it.
 

silva

Über Member
Location
Belgium
Unevenly distributed chain links wear should be confirmed with the derailer moving up and down every chain rotation, no?
Since the spring on the derailer tensions the chain, so if parts are longer / shorter under a same tension, the mount of the derailer should compensate by moving.
 

I like Skol

A Minging Manc...
Unevenly distributed chain links wear should be confirmed with the derailer moving up and down every chain rotation, no?
Since the spring on the derailer tensions the chain, so if parts are longer / shorter under a same tension, the mount of the derailer should compensate by moving.

I don't think this works because even if some sections of the chain are more worn than others the overall length will be constant so the derailuer will not move.
 

CharleyFarley

Senior Member
Location
Japan
Unevenly distributed chain links wear should be confirmed with the derailer moving up and down every chain rotation, no?
Since the spring on the derailer tensions the chain, so if parts are longer / shorter under a same tension, the mount of the derailer should compensate by moving.

The difference between .50 and .75 is so slight that I can't imagine it would affect the derailleur. In one of the articles I found it mentioned how some of the teeth are ground to assist the chain moving from one cog to another, and that they have an effect on uneven chain wear.

DSC_0133.JPG
Here's a picture of my old cassette showing the angled teeth. I think this is what the article was talking about but I can't see how they would cause uneven chain wear.

DSC_0133.JPG
 
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si_c

Guru
Location
Wirral
Chain cleanliness is another factor. I've used a chain checker on a chain and it's been fine, properly cleaning it by running through the ultrasonic bath and removing all the dirt and relubricating can often mean the chain is now being indicated as being worn.

Cleaning grit and dirt out of the rollers and bushings before checking is probably a good idea.
 

Paulus

Started young, and still going.
Location
Barnet,
Chain cleanliness is another factor. I've used a chain checker on a chain and it's been fine, properly cleaning it by running through the ultrasonic bath and removing all the dirt and relubricating can often mean the chain is now being indicated as being worn.

Cleaning grit and dirt out of the rollers and bushings before checking is probably a good idea.

Same here. I gave the chain on my Tourer a thoroughly good clean, it did need it. When it went back on it was running really rough. Checked it with a chain checker and it had gone way past the wear markers. Also, I could almost lift it off the big ring just to reiterate that it had gone well past its useful life.
 

silva

Über Member
Location
Belgium
I don't think this works because even if some sections of the chain are more worn than others the overall length will be constant so the derailuer will not move.
But that overall length is determined also by the spring of the derailer. It's the spring that tensions the chain, that thus alters the chains length, and on places with more worn links, makes it longer than on places with less worn links. The spring thus has to compensate the length difference, which it doesn't since the springs constant remains, leaving its position as compensation, so it should move?
 
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