Ch ch ch ch chain wear

Posted by Greg on 11th Feb 2024

Ch ch ch ch chain wear

Chain Wear & Drivetrain Longevity 

Those that know me must have been subject to my famous chain wear monologue by now, and why the mythical figure of 05.% is so crucial when checking a chain.

One of the most heart-breaking (and common) conversations we have in the workshop goes along the lines of:

Vanguard Cycles (VC): I've checked the bike over, and sadly your chain is well past the wear limit for 11-speed drivetrains.

Keen Cyclist (KC): Oh, that's a surprise, as I've only done 5000 miles.

VC: Unfortunately in the UK, conditions are so variable that the only way to keep on top of it is to regularly measure your chain wear. We recommend once a month or when you clean your bike, whichever is sooner.

KC: Ah. That's news to me. OK So let's fit a new chain, job done.

VC: Unfortunately a new chain won't work in this instance, as the cassette & chainrings will have been worn down to match. A new chain, cassette & chainrings are needed to ensure the chain doesn't slip and that everything works properly. The cost to do that is £400.

KC: Oh...that's a real bombshell. Is there anything else that can be done?

VC: Well, the other option is to carry on riding until the performance is totally degraded, and then change the same parts. So doing the same job but riding the current parts into the ground. 

KC: Ok let me have a think about it.

VC: Sure, absolutely. I'd also be very happy to show you how to use a chain checking tool, and which ones we recommend, so you can get the most mileage out of the components by regularly replacing the chain.

I've been meaning to shoot a video for our YouTube channel on the topic, but recently Adam Keiron of Zero Friction Cycling (ZFC) pipped me to the post.

If you can, I'd really recommend watching this video segment (or the whole thing if you have time!) as it explains chain wear, what exactly the 0.5% means, and why going past this can be costly for you and the environment: 


A chain over 0.5% wear will very quickly start to eat the chainrings and cassette sprockets. 

Once this happens, a new chain can't be installed because it will run poorly and slip, and a new drivetrain will be required. 

The chain checking tools are cheap when compared to 11- and 12-speed components, and easy to use once you know how.

Modern chains wear out at a staggeringly fast rate when compared to the singlespeed bikes we used to thrash as kids.

The only way to deal with this is regular maintenance & cleaning with quality products, and regular chain replacement.

This is exacerbated by ebikes, offroad/gravel riding, commuting and winter muck.

We can recommend the following tools, if you don't have one (NB: These are sponsored links)

Shimano TL-CN42 (as used in the workshop)

Park Tool CC-4

Pedros Chain Checker + II

KMC Digital Chain Checker (as used in the workshop)

It's a hot topic both in the workshop and in the classroom, drop me a line if you want more info!