New chain: when?

PhilipTom

What are the signs and symptoms of a knackered chain? I have no idea but wondered whether some of my very lumpy gear changes are down to the chain needing to be retired.

No idea what mileage it has done but I do keep it well cleaned and lubed, and the gears have been serviced fairly recently (about 1000 miles / a month ago).

Thank you.

schweiz

Buy a chain checker:

http://www.ribblecycles.co.uk/productde ... 0000000000

It'll tell you when the chain stretch is greater than 0.75% and greater than 1%. I replace my chains before they get to 1%, and I am currently getting about 2400km per chain, but how much you get depends on riding style (spinner or grinder), gear selection (avoiding crossed gears - Outer CR, Inner Rear Cog and vice versa), when you change gear (i.e. don't change too late going up a steep hill when your cadence is really low), how often you clean and lube it etc.

If your chain really is knackered, change the cassette (and possible the chain rings) at the same time or else your new chain will soon be knackered too.

I cycle for 800km with a new chain, then swap it for another new one, ride 1600km with the second one, put the first chain back on, ride 1600km with that and then ride 800km with the second chain. Both chains are then wearing equally relative to the cassette. Then check cassette wear and if it's okay, start again with 2 new chains. Don't know if it really does make things last longer, but my current rear cassette is currently on chain number 5 and is still going strong. Chain rings should last 3-4 time longer than a cassette, simple because they turn that much slower.

topdude

Hi, the simplest and cheapest test is using a 12" steel rule.
The chain links have a 1/2" pitch so stretch out the chain and measure carefully from the edge of one pin to the same edge 24 links away.
A new chain will be spot on 12"
Slightly worn but still ok will be 1/16" longer
Very worn will be 1/8" longer
If you let it wear to 1/8" longer then you would probably need to change the cassette at the same time.
Apologies if you think in metric, you will have to do your own conversions from imperial

balthazar

Topdude is right. Any old ruler is a better tool for establishing chain wear than expensive specialist tools. 1% increase in length over 12 inches (sixteenth of an inch) is the latest you should replace the chain.

hambones

This will be of no help whatsoever but I've done around 8000 miles and still on my first chain!!

:shock:

PhilipTom

Actually, Hambones, it does help.

I was beginning to think that I was a complete numpty for never changing the chain on a bike that I've done 4,000 miles on and which must have done a few thousand before I got it.

Sounds like some people are changing chains every 1000 miles: yikes, cycling is not looking quite as cheap as it was......(chain, cassette, tyres, brakes...............)

wiffachip

hambones wrote:

This will be of no help whatsoever but I've done around 8000 miles and still on my first chain!!

:shock:

hambones, you've got too much common sense for this thread, you'll be telling me next that you use oil on it

Campy King

I am quite hard on chains and change mine every 1000-1500 miles, this saves a lot of money on cassettes and chain rings as a new chain is less harsh on other components than a work old one.

neeb

Then check cassette wear and if it's okay

Any tips for actually measuring this? (other than observing that your chains are wearing out more and more quickly...)

singlespeedexplosif

I change chains every month - that's about 1000 miles.

doktorsteve

I bought a new chain and cassette after 1200 miles because of jumping and bad shifting.

Then I measured the chain and found no wear at all.

10 minutes with the bike upside down was all that was really needed to get the shifter adjusted right.

PhilipTom

Errmm......well today I lost another spoke on the rear (4th in 3 weeks) and decided a new wheel was overdue, thus a new cassette (up from a 105/8 to an Ultegra/9) and thus a new SRAM chain (with superlink).

After a small hesitation, sizing and fitting the new SRAM was very easy and the difference is, well, fairly astonishing.

Of course, I am benefiting from stepping up to a 9 cog cassette (same range tho') and the new lighter wheels help but the chain definitely has the most instantaneous effect. I think I know what instant power delivery now means.

So, to conclude, I probably should have got a new chain a long time ago. Numpty.

kettrinboy

using a steel rule my chain on my Scott CR1 measures 12.032" so about 0.25% worn and thats done 4600 miles but thats in mostly dry conditions and i dont put out much in the way of power either which must have helped its longevity so far.

John C.

how much is a chain ? 10 pounds +
how much is a cassette ? 35 pounds +
how much is a chain checker ? 7 pounds

Now I may be tight yorkshire man, but I bought a chain checker and I replace chains when they start wearing , not chains and cassettes because I've let the chain live too long

John C.

PhilipTom wrote:

Actually, Hambones, it does help.

I was beginning to think that I was a complete numpty for never changing the chain on a bike that I've done 4,000 miles on and which must have done a few thousand before I got it.

Sounds like some people are changing chains every 1000 miles: yikes, cycling is not looking quite as cheap as it was......(chain, cassette, tyres, brakes...............)

Chains tend to snap on steep hills under maximum load, when they do your foot decends rapidley and you pray your crossbar is low enough.