Support road.cc

Like this site? Help us to make it better.

feature

Do you need a new chain? Find out the easy way to tell

A worn chain can wreak havoc on the rest of your transmission. Read our expert guide to learn how to tell that it's time for 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

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

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 if it gets to 1/8in (or 2/16) mark it has gone beyond the point at which it needs replacing.

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

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 if it gets to the 25.6cm mark it has gone beyond the point at which it needs replacing.

If you want to get more accurate, it's usually advised that you replace chain designed for 10 or fewer gears when it has lengthened by 0.75% – so when 10 links measures 25.59cm – and that an 11-speed or 12-speed chain is replaced when it has lengthened by 0.5% – so when 10 links measures 25.53cm. 

If you have a one-speed or two-speed bike, replace your chain as it reaches 1% wear - so when 10 links measures 25.65cm.

Figures like these are obviously very difficult to gauge with a normal ruler, which is why we'd advise the use of a chain wear indicator.

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

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

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 been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. 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 winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

Add new comment

74 comments

Avatar
part_robot | 7 years 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.

Avatar
Mungecrundle | 7 years ago
1 like

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.

Avatar
Yorkshire wallet | 7 years ago
1 like

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

miles, probably need a new one.

Avatar
ktache | 7 years 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.  

Avatar
ibr17xvii | 7 years 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.

Avatar
BrokenBootneck replied to ibr17xvii | 7 years 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. 

Avatar
DaveE128 replied to BrokenBootneck | 7 years ago
2 likes

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.

Avatar
The _Kaner replied to BrokenBootneck | 7 years 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
matthewn5 replied to ibr17xvii | 7 years ago
2 likes

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...

Avatar
Augsburg replied to ibr17xvii | 7 years 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.  

Avatar
Paul__M | 7 years ago
5 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

Avatar
nortonpdj | 7 years ago
11 likes

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

Avatar
Mat Brett replied to nortonpdj | 7 years ago
0 likes

nortonpdj wrote:

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

 

The scope and aim of this article is clearly set out in the headline: When should I replace my chain?

And in the standfirst: Here's how to know when it's time to fit a new one

There's plenty more information we could have included about chain longevity, chain maintenance, how to change your chain, and so on, but that's not what this article is about. The article is an answer to an often asked question.

For advice on cleaning and lubing your chain go to http://road.cc/content/feature/164006-how-clean-and-lube-your-bikes-chain

Avatar
stenmeister | 7 years 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.

 

Pages

Latest Comments