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As far as I understand, the difference between 10 and 11 speed chains is in the thickness of the plates. The length and the inner width of each link remain the same. This in turn means the size/thickness of teeth on the chainring and cassette are the same in an 11 speed system as in a 10 speed system.

So what mechanical effect is taking place to cause the recommendation that 11 speed chains are replaced at 0.5% rather than the 0.75% for 10 speed?

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  • 3
    My Ultegra R8000 is on its fourth chain now, all replaced after 0.75% wear. More than 10Mm on the drivetrain. Still working perfectly fine. When the chains get close to 0.75% they start to make noise but still work good enough. So from personal experience I don’t see a reason for the 0.5% recommendation. Only makes people throw away chains which would still be good for >300km.
    – Michael
    Mar 9 at 9:26
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    Can you provide sources for this information? I can only find Park Tool suggesting this, and their tool is rubbish, you can get 0.5% on an unused chain sometimes and then where is your basis for comparison.
    – Noise
    Mar 9 at 11:21
  • @JoeK I originally saw it as part of an answer to a question here. I then found it in the Park Tools article you reference and in an article from Road.cc. I can't however find anything in any recommendations from manufacturers
    – Andy P
    Mar 9 at 11:46
  • @AndyP Campagnolo give specific recommendations based on the measured pin-pin length of 6 links. Shimano have their own tool that measures in a different way to the park tool. It is not as clearcut a question as it seems.
    – Noise
    Mar 9 at 13:02

2 Answers 2

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My understanding is that it is simply a reflection of the hypothesis that tighter tolerances lead to smaller ranges of safe operation.

Specific choices for threshold values are completely arbitrary. The number 0.75% is as good as 0.7% or 0.8%. Especially given the mediocre accuracy of the tools used to measure the stretch, and variety in usage patterns and component quality.

If one assumes that 11-speed chains are about 10% "finer" than 10-speed ones, the simplest linear extrapolation would give that 0,75 - 10% == 0,675 (%) of stretch is correct threshold margin for 11-speed chains. But again, nobody seemed to care about such a fine difference. So everybody just went after the closest "round" number, i.e. 0.5%, erring to the safer side.


My personal experience with several 10-speed cassette/chain MTB combos shows that replacing chains at 0.75% stretch is a bit too late. The new chain (with 0% initial stretch) on the old cassette occasionally skips and hops for the first couple of weeks of use. Then it wears in a bit and works as expected. Because of this, I am reconsidering to start using 0.5% as threshold even for 10-speed systems.

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The main reason is probably that 11-speed cassettes have narrower sprockets (so they wear faster) and if the cassette has 11 sprockets, it costs more to manufacture than a cassette with 8 sprockets -- especially considering that usually more speeds mean the biggest sprocket is larger.

I can buy 8-speed cassettes for 25 EUR, but 11-speed cassettes are 70 EUR.

A 8-speed chain costs 16 EUR, but 11-speed chain costs 30 EUR.

Thus, the cassette-to-chain price ratio is much bigger for 11-speed systems (2.33) than for 8-speed systems (1.56). It used to be the case that the ratio was even smaller for 8-speed systems, in fact smaller than 1.0, but due to parts shortage the price of 8-speed cassettes has increased recently.

If the cassette is expensive compared to chains and cassettes wear fast, it makes sense to not let the chain damage the cassette.

If the cassette is not so expensive compared to chains and the thick sprockets don't wear very fast, the most economical point to replace the chain is with more chain wear.

Besides, not everyone replaces 8-speed chains at 0.75%. I replace all chains, regardless of the sprocket count, at 0.5%.

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  • Are you sure 11 speed has narrower sprockets than 10 speed? I was under the impression the extra space was made by removing the 10 speed spacer and making the gaps between the sprockets narrower (hence the chains having thinner plates and same inner width).
    – Andy P
    Mar 14 at 9:11
  • I do however agree that the recommendation is likely due to the high cost of 11 speed cassettes
    – Andy P
    Mar 14 at 9:12

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