Uneven chain wear!

[Globalti]

Anybody seen this? My DA chain has about 2500 entirely clean dry miles on it and my chain checker is showing some links to be grossly worn while others are showing little wear.

I've never experienced such uneven wear. It's a climbing bike and I do climb a lot of hills so I'm wondering if cack-handed shifts under extreme tension could have actually stretched some links.

Any thoughts?

 

[the snail]

My guess is that it was like that from new, and you're seeing variation in the rollers rather than wear to the pins/bushings.

 

[twentysix by twentyfive]

actually stretched some links

Chains don't stretch. The pins and bushings wear.

Do you only use one gear such that you only put wear on the chain on one part of the cycle? Unlikely as "quantisation" would be required.......

 

[Globalti]

No I use every gear with enthusiasm while wondering why people like singlespeeds!

 

[Ajax Bay]

I'd have thought the OP would be pleased to get 2500+ miles out of an 11sp chain before it elongated beyond 0.75%. I have not knowingly experienced some links elongating and others not, but I habitually measure a long section of chain, not individual links.

 

[Globalti]

My chain-checker measures about 8-10 links I guess. Moving it around on the chain shows some areas to be hardly worn at all while other areas are badly worn. Very strange, never seen that before. It does make quite an uneven noise while I'm riding. Anyway I've ordered a new one.

 

[ColinJ]

My cousin came down from Scotland recently to tackle 500 km worth of my favourite local hilly routes in 5 days of cycling. (A good effort, considering that all had over 2,000 metres of climbing and he did them at sub-6 hour pace, including stops! )

When he brought his bike in from his car, I took one look at it and told him that his chain was badly worn. I didn't need a chain checker - it was on the big ring and there was a massive gap between the ring and the chain. I got hold of the chain midway round and could pull it completely clear of the teeth! We went and got a new chain and cassette the next day...

 

[Ajax Bay]

My chain-checker measures about 8-10 links I guess. Moving it around on the chain shows some areas to be hardly worn at all while other areas are badly worn. Very strange, never seen that before.

I guess the lesson may be that, if you use a chain checker, any check needs to be repeated on different sections of the chain, for assurance. Personally I use a 18" steel rule along the upper (tensioned) 12" stretch from FD cage to cassette.

 

[Alan O]

One way to completely avoid worrying about chain stretch is to buy cheap ones that break long before it becomes a problem. (Viz top tip there )

 

[Oldfentiger]

Never thought about this on bicycles before - I suppose the function of the rear mech cage will mask evidence of tight spots.
Motorcycles though: there is always a tight spot to find when adjusting chain tension, even when installing a new chain on existing sprockets.
Never knew why

 

[Ajax Bay]

One way to completely avoid worrying about chain stretch is to buy cheap ones that break long before it becomes a problem.

Tell us about the time your last cheap chain 'broke' and how many miles the chain had done. Were you enjoying climbing out of the saddle at the time, putting 'powah' down? Did you need first aid?
One doesn't need to 'worry' about chain elongation (they do not 'stretch'): just record mileage, measure regularly with a reliable method and replace the chain at the 0.75% point; or just let it and the cassette run on together till the system 'slips' (then replace both).
Despite planning to, I failed to replace my (9sp) chain before LEL last year - it only had 1800k on it before I travelled to the start. But after LEL it was too far gone (3300k by then) so ran it on with the cassette and by the time it slipped they'd done just under 6000k (so replaced both). Current cassette has had two chains each doing ~2500k and is on its third.

 

[Alan O]

Tell us about the time your last cheap chain 'broke' and how many miles the chain had done. Were you enjoying climbing out of the saddle at the time, putting 'powah' down? Did you need first aid?
One doesn't need to 'worry' about chain elongation (they do not 'stretch'): just record mileage, measure regularly with a reliable method and replace the chain at the 0.75% point; or just let it and the cassette run on together till the system 'slips' (then replace both).
Despite planning to, I failed to replace my (9sp) chain before LEL last year - it only had 1800k on it before I travelled to the start. But after LEL it was too far gone (3300k by then) so ran it on with the cassette and by the time it slipped they'd done just under 6000k (so replaced both). Current cassette has had two chains each doing ~2500k and is on its third.

Look up "Viz top tip" - it was a joke

But yes, leaving it until it starts to slip is what I've always done.

 

[Alan O]

[QUOTE 5331428, member: 9609"]it was the second gear the slipping started with
View attachment 421699 [/QUOTE]
Those teeth look like the Alpine stages of the Tour de France!

 

[ColinJ]

Tell us about the time your last cheap chain 'broke' and how many miles the chain had done. Were you enjoying climbing out of the saddle at the time, putting 'powah' down? Did you need first aid?

Well, in my case - February 16th, 2016!

I reckon the chain had done at most 1,000 miles, probably less.

I was about to enjoy climbing out of the saddle at the time. I had just stood up and was ramping up the 'powah' when I felt a clunk and heard a ticking sound so I immediately sat down again, at which point the chain 'deloopified'.

Emergency resitting prevented an almost inevitable gonad-to-toptube interface with potential road faceplant chaser, so first aid was not required.

 

[CharleyFarley]

I clean and lube my fat bike chain every 100 miles, and I only ride on pavement, no rain or muck. Today, it was time for my 100-miles service and I was amazed to find parts of the chain were showing 50% and other parts 75%. The chain is SUMC, made by a former engineer for KMC chains. I don't know how many miles I've put on it, perhaps between 3 and 4 thousand. I'm not complaining, and I'd buy another SUMC. I like the highly polished finish.

I've now done 11,500 miles since it was new.
To clean it I wipe it with a rag, first. Then use a Park chain-cleaning tool, running it through a citrus cleaner. Then dry it, and run the bottle of lube along the links. Then I turn the pedals backward for about a dozen revolutions. After that, I follow the instruction to let it sit for several hours before riding.