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Here's how to know when it's time to fit a new one

Your bike chain will gradually wear with use and will need changing from time to time in order to maintain your drivetrain’s performance. Worn chains shift poorly, wear sprockets quickly, and sometimes break. 

So when should you change your chain?

“For chain replacement we do not state 'every x kms' as this is not possible,” says SRAM. “Chain wear is based on multiple factors including maintenance (clean/lube), use conditions (water/mud/sand), user shifting patterns and overall drivetrain condition (cassette/ chainring wear).”

Cross-chaining: is it really all that bad?

Campagnolo agrees.

“It is difficult to pin down an exact number to kilometres due to the fact that riders come in different weights and sizes, ride differently, shift more or less frequently, develop more or less wattage, ride on flat or hilly terrain, clean or nasty conditions, take care or leave their chain dirty… all of which create large variables in just how much wear and tear is created,” says Campag's Joshua Riddle.

“It can vary between 3,000km to 8,000km generally speaking, but it could be less or even more in some cases.”

KMC X10.93 Chain

KMC X10.93 Chain

First, you need to replace your chain when you spot any damage (a deformation or crack). You should also check your chain regularly to see if it has worn to the point that you need to change it. 

There are several ways to check whether your chain has reached this stage?

Measuring with a ruler

You can check for chain wear with a ruler. It’s a little easier if you go with imperial measurement here because one complete chain link of a standard chain measures 1in.

Start at one link pin and measure 12 complete links. You need to put some tension on the chain to be accurate.

Chain Checking inches - 1.jpg

Chain Checking inches - 1.jpg

On a standard new chain, 12 complete links will measure 12in, but when a chain is worn the 12in mark of the ruler won’t quite reach the relevant link pin.

If the distance from the 12in mark to the centre of the link pin is less than 1/16in, your chain is fine, but more than that and it’ll need replacing.

If you use metric measurements, it’s easiest to measure 10 links.

Chain Checking cm - 1.jpg

Chain Checking cm - 1.jpg

On a standard new chain, 10 complete links will measure 25.4cm.

If the distance from the centre of one link pin to the centre of the link pin 10 complete chain links away is up to 25.5cm, your chain is fine, but more than that and it’ll need replacing.

 

Chain wear indicator

A chain wear indicator, sometimes called a chain checker, is an inexpensive gauge that does exactly what its name suggests. 

Park Tool Chain Checker - 1.jpg

Park Tool Chain Checker - 1.jpg

This is Park Tool’s CC-3.2 chain checker with an RRP of £9.99, although you’ll find it cheaper if you look around. Other brands offer similar instruments.

You hook the curved end into the chain and if the gauge tip on the other end fits completely into a chain link, the chain is worn to the point it needs replacing (one side measures 0.5% wear, the other side measures 0.75% wear). 

 

Measuring by eye

There’s one other simple method of checking for chain wear. 

Chain Checking by hand - 1.jpg

Chain Checking by hand - 1.jpg

KMC advises, “If you do not have a gauge to test the chain’s elongation you could roughly check by putting the chain on the outer chainring and lifting up the chain from the middle of the chainring. If you can lift it more than half a link, the chain or chainring, or both, are probably worn.”

The chain in the picture is almost new so minimal lift from the chainring is possible.

Check out our advice on how to replace a chain. 

Mat has worked for loads of bike magazines over the past 20 years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for seven years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.

42 comments

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stenmeister [342 posts] 3 months ago
2 likes

I'll get the ball rolling with my experience....

Good bike gets two chains a year, doing roughly 3500km on each.

Winter bike does about 2000km per chain, changing every autumn.

If I could afford it, I'd buy more chains for the good bike throughout the year.

 

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nortonpdj [167 posts] 3 months ago
7 likes

One simple thing not given enough prominence in the article: the cleaner you keep your drivetrain, the longer the chain will last.

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ibr17xvii [166 posts] 3 months ago
2 likes

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

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Paul__M [33 posts] 3 months ago
2 likes

Worth emphasising that if you change it too late you ruin the teeth, which is a much bigger job. Plus nothing feels as good as a new chain for so little money, so one job not to overlook; something I've been guilty of more than once  2

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ktache [524 posts] 3 months ago
1 like

I purchased the very excellent Park CC-2 chain checker many years ago, my only regret is not using it enough.

My 7 speed fitted with an 8 speed chain will be changed well before it get's to the 1% mark, relativly cheap casette.  Just taken the ebay discovered XTR off, will use in the summer when the filth is not so bad, Sram no longer make the PC-890 so couldn't be constantly replacing the chain at 0.75%.  Found a couple, will have to try the KMC eqivilent.  My commute is more extreme than I have ever done, sections of quagmire, wet lubing 3-4 times a week, and a full clean every 1-2 weeks.  Lot of fun though.

The 9 speed XTR will get changed hopefully before 0.75%, that casette is £150, gutting when you check that chain and it's managed to go far beyond 0.75%, you change the chain hoping it will be alright and get the clunking when laying down power.

For some ridiculous reason I cannot put low grade parts on either of them.  

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Yorkshire wallet [1075 posts] 3 months ago
1 like

Adds new chain to 'to do' list. Think I'm hitting 3000+

miles, probably need a new one.

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BrokenBootneck [207 posts] 3 months ago
1 like
ibr17xvii wrote:

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

 

i went from KMC to SRAM it wore out very quickly in comparison on my commuter. Back with KMC now. 

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Mungecrundle [705 posts] 3 months ago
0 likes

Ultegra 11spd chain is £20 without too much effort. They are pretty much a disposable routine maintenance item.

When my good bike was a 9spd I replaced it every 1000km and moved the old one down to my commuter mtb. I think it is one of those false economies to run a worn chain. Shifting is poorer, power transfer is poorer, they sound miserable and you add extra wear on more expensive components i.e the crankset and cassette.

Quick links make chain removal and replacement a simple job.

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matthewn5 [1006 posts] 3 months ago
1 like
ibr17xvii wrote:

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

I'm using a Chorus chain that's so far lasted two winters with no measurable stretch using an steel rule (in inches) and the method above.

I was getting only one winter from Ultegra chains.

Chorus 11 speed chains are about £26 and Ultegra 11speed about £21, so I think I'm ahead...

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Darkerside [76 posts] 3 months ago
2 likes

One of the down sides of a recumbent. Chain swaps need three of the damn things...

Feels a little less disposable at £60+ a pop.

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Zjtm231 [40 posts] 3 months ago
2 likes

Ive gone through a chain in well under 1000km.  Stop start riding  in London in the winter...and being 100kgs probably did for it... 

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BBB [452 posts] 3 months ago
1 like

Rotate 2-4 chains every few hundred miles. The whole system will last longer and you'll never need to measure the chain wear.  

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DaveE128 [858 posts] 3 months ago
1 like
BrokenBootneck wrote:
ibr17xvii wrote:

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

 

i went from KMC to SRAM it wore out very quickly in comparison on my commuter. Back with KMC now. 

If you let the KMC chain get too worn, the chainrings and sprockets would be worn to match. This would cause rapid wear to the new SRAM chain.

Also, another reason for not letting chain wear get too bad is that putting a new chain on a significantly worn chainring causes chain suck, especially in wet and dirty conditions.

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Vejnemojnen [240 posts] 3 months ago
1 like

campag recommendation is the most reasonable IMHO

 

132.60mm measured for 6 links. see the picture attached.

 

http://i-vol.com/bikes/campagnolo_chain_info.jpg

 

shifting performance begins to deteriorate around this point though, so you'll notice it certainly, whitout measuring  1

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part_robot [198 posts] 3 months ago
0 likes

I also endorse the Ultegra and Dura Ace chains (depending on which I can find on offer at a given time). For some reason I've not be able to the bottom of, KMC chains are noisier on Ultegra Di2 for me.

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Welsh boy [350 posts] 3 months ago
5 likes
BBB wrote:

Rotate 2-4 chains every few hundred miles. The whole system will last longer and you'll never need to measure the chain wear.  

Rotating chains has NO effect on longevity whatsoever, it is yet another one of those myths picked up on clubruns/forums which people pass on as if it were the absolute truth.  Do you really think that taking a chain off and giving it a rest makes it last longer?  Do you really believe that?  Really?

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pockstone [97 posts] 3 months ago
1 like
Welsh boy wrote:
BBB wrote:

Rotate 2-4 chains every few hundred miles. The whole system will last longer and you'll never need to measure the chain wear.  

Rotating chains has NO effect on longevity whatsoever, it is yet another one of those myths picked up on clubruns/forums which people pass on as if it were the absolute truth.  Do you really think that taking a chain off and giving it a rest makes it last longer?  Do you really believe that?  Really?

It's Friday tea time , so I'm not in lateral thinking mode, but might rotating chains reduce wear on the chainrings and cassette? 

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ChrisB200SX [357 posts] 3 months ago
1 like

Yeah, there's an optimal number of chains, which varies with use, so the chains, cassette and chainset all get to the end their lives around the same time. Sounds like a lot of faff to me... But if you like removing and fastidiously cleaning chains...

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captain_slog [385 posts] 3 months ago
6 likes

Ooh sir sir, me sir, I know this one.

You may and/or should replace your chain in any of the following circumstances.

A) The bloke in the bike shop rests his metal gadget on it, sucks his teeth and shakes his head

B) Bang on the wheel of your lead-out man, you round the final curve of the 1st-cat crit, put down all of your awesome power for the sprint ... and it snaps

C) You see a nice shiny new one favourably reviewed on road.cc

Can I haz the intern job now please?

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BBB [452 posts] 3 months ago
0 likes
Welsh boy wrote:
BBB wrote:

Rotate 2-4 chains every few hundred miles. The whole system will last longer and you'll never need to measure the chain wear.  

Rotating chains has NO effect on longevity whatsoever, it is yet another one of those myths picked up on clubruns/forums which people pass on as if it were the absolute truth.  Do you really think that taking a chain off and giving it a rest makes it last longer?  Do you really believe that?  Really?

The chains may not last much longer (if at all) but the whole drivetrain will. By rotating N number of chains you emulate the super chain with rate of wear / N.

You cassette and chainrings will be exposed initially to lower wear and all chains will be gradually "stretching" by the same amount so you avoid grinding the teeth of you cassette first with 0.75% worn and then with new chain (that's assuming that you remember to replace your chain on time...)

As I said before this system offers a simple answer to "when to replace the chain" problem.

 

 

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kevvjj [197 posts] 3 months ago
4 likes

Honestly can't be arsed with all this chain rotation/replacement bullshit. I just ride my chain and cassette into the ground (until shifting becomes a real problem) then replace both at the same time. Last chain and cassette replaced three years ago both now with 18000 km on them and still shifting fine. I don't race,  so couldn't care less if I miss a shift every now and again. Oh, and I'm not fooled by the marketing ploy of expensive chains - they wear just as fast as the cheap ones, you're just paying for the 'shiny stuff' and a miniscule weight difference - after a month in the filth of winter they all look, wear and shift the same.

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beezus fufoon [673 posts] 3 months ago
1 like
kevvjj wrote:

Honestly can't be arsed with all this chain rotation/replacement bullshit. I just ride my chain and cassette into the ground (until shifting becomes a real problem) then replace both at the same time. Last chain and cassette replaced three years ago both now with 18000 km on them and still shifting fine. I don't race,  so couldn't care less if I miss a shift every now and again. Oh, and I'm not fooled by the marketing ploy of expensive chains - they wear just as fast as the cheap ones, you're just paying for the 'shiny stuff' and a miniscule weight difference - after a month in the filth of winter they all look, wear and shift the same.

ditto

...although I do have 5 bikes in rotation, so that's a 15 year replacement time frame for me  1

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Welsh boy [350 posts] 3 months ago
0 likes
BBB wrote:

The chains may not last much longer (if at all) but the whole drivetrain will. By rotating N number of chains you emulate the super chain with rate of wear / N.

You cassette and chainrings will be exposed initially to lower wear and all chains will be gradually "stretching" by the same amount so you avoid grinding the teeth of you cassette first with 0.75% worn and then with new chain (that's assuming that you remember to replace your chain on time...)

As I said before this system offers a simple answer to "when to replace the chain" problem.

 

 

So you are saying that by putting a new chain on a transmission that is already starting to wear (and will continue to wear when you use it with whatever chain you fit) you will increases the life of the transmission?  Is that what you are saying?  I don't think so, in fact you will expose your new chain to a worn transmission which will increase the wear rate of your new chain.

Avatar
BBB [452 posts] 3 months ago
2 likes
Welsh boy wrote:
BBB wrote:

The chains may not last much longer (if at all) but the whole drivetrain will. By rotating N number of chains you emulate the super chain with rate of wear / N.

You cassette and chainrings will be exposed initially to lower wear and all chains will be gradually "stretching" by the same amount so you avoid grinding the teeth of you cassette first with 0.75% worn and then with new chain (that's assuming that you remember to replace your chain on time...)

As I said before this system offers a simple answer to "when to replace the chain" problem.

 

 

So you are saying that by putting a new chain on a transmission that is already starting to wear (and will continue to wear when you use it with whatever chain you fit) you will increases the life of the transmission?  Is that what you are saying?  I don't think so, in fact you will expose your new chain to a worn transmission which will increase the wear rate of your new chain.

By the time your first chain reaches the end of useful lifespan - 0.75% stretch in a traditional method, three (e.g.) chains used in rotation will be worn approximately just 0.25% each, exposing other components to much less wear. That's the main difference.

I don't quite understand why some people here feel so worked up about it. Whether it's faff and it's worth it or not , it's up for individuals to determine.

It takes no time to disconect a KMC link and put another chain on. Many people do it anyway when they clean their drivetrains. 

Avatar
Augsburg [19 posts] 3 months ago
1 like
ibr17xvii wrote:

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

I have a Salsa Fargo adventure bike as my primary bike.  It has a SRAM 10-speed 2x drivetrain.  It came with SRAM PC-1051 chain, which lasted 800 miles, riding in winter and with lots of hill climbs.  I change my chain at 0.5% stretch measured with the Park tool.  I upgraded to PC-1071 chain, which costs about US$5 to US$10 more on Amazon (US$29 vs US$40).  The PC-1071 chain got 1,450 miles, or not quite twice the miles  - which for me, is worth the extra cost.  

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ktache [524 posts] 3 months ago
3 likes

There is nothing wrong with buying the lady in your life something shiny.

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The _Kaner [1074 posts] 3 months ago
1 like
BrokenBootneck wrote:
ibr17xvii wrote:

Views on buying a "better" more expensive chain?

Had a SRAM chain on my winter bike that only lasted under 1000 miles & changed it at 0.75 wear although it was in the worst of the weather.

Got a KMC on this time & paid slightly more so interested to see how that goes.

 

i went from KMC to SRAM it wore out very quickly in comparison on my commuter. Back with KMC now. 

Slightly more expensive than the shimano ultegra (great chain)...but I use the KMC X10/X11 SL variants (Gold - TiNi coating) excellent wear (and bling) on these and can be had for around €30 a pop inclusive of the missing link

Avatar
The _Kaner [1074 posts] 3 months ago
0 likes
Welsh boy wrote:
BBB wrote:

Rotate 2-4 chains every few hundred miles. The whole system will last longer and you'll never need to measure the chain wear.  

Rotating chains has NO effect on longevity whatsoever, it is yet another one of those myths picked up on clubruns/forums which people pass on as if it were the absolute truth.  Do you really think that taking a chain off and giving it a rest makes it last longer?  Do you really believe that?  Really?

I have heard that if you remove and clean the chain, leaving a thin film of lubricant to coat it, then pop it in the microwave for 5 minutes, it will 'shrink' the wear on the chain....

Avatar
Paul__M [33 posts] 3 months ago
0 likes

Rotating chains sounds a good idea, but when I got my spare out of the draw amazingly it had started to rust, so storage needs to be well lubricated if the garage is at all damp. That's a bit messy for me, so am going the 'disposable item' route.

Avatar
Paul__M [33 posts] 3 months ago
0 likes
Darkerside wrote:

One of the down sides of a recumbent. Chain swaps need three of the damn things...

Feels a little less disposable at £60+ a pop.

 

That's another reason my High Racer is a 'Sunday' bike. Must get it off the trainer now the clocks have moved.

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