# Chain/cassette replacement



## Greg (Oct 8, 2008)

Any rule of thumb for the chain? Yearly? It's my understanding that replacing the chain regularly extends the life of the chainrings and cogs, correct? Excluding any direct damage, how long should a cassette last generally? I assume chainrings gets changed with the cassette.


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## bvibert (Oct 8, 2008)

Most people seem to say replace the chain once a year, so even more frequently if the ride a lot.  A worn out chain will definitely wear out your cassette and rings.  If they get bad enough then they won't mesh well with a new chain.  You can measure the chain stretch using either a ruler or a chain checking gauge.

Some good info on this page:
http://www.sheldonbrown.com/chains.html

Including this on how to measure for stretch:


> Measuring Chain Wear
> 
> The standard way to measure chain wear is with a ruler or steel tape measure. This can be done without removing the chain from the bicycle. The normal technique is to measure a one-foot length, placing an inch mark of the ruler exactly in the middle of one rivet, then looking at the corresponding rivet 12 complete links away. On a new, unworn chain, this rivet will also line up exactly with an inch mark. With a worn chain, the rivet will be past the inch mark.
> 
> ...


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## cbcbd (Oct 8, 2008)

Don't know if there is a rule of thumb. I know someone posted here a long time ago that they replaced it after 15 rides - but, that is pretty subjective.

The chain stretches over time, with this stretch and grinding use it can wear the teeth on your chainrings and cogs so the teeth end up looking like shark fins rather than a even "wave". That is fine if you keep the same chain and that chain lasts a long time. But if you break your chain, a new chain will not sit properly on your worn cogs and the chain will skip over the teeth - it is basically not rideable. At that point you have to get a new cogset to use with your new chain.

If you want to take guesswork out of it you can get a chain wear tool or do the same yourself with a homemade substitute:
http://www.performancebike.com/shop/profile.cfm?SKU=23208&subcategory_ID=4204

Basically all it measures is how much the chain has stretched, which kinda should give you an idea of how much it would wear your cogs - the more stretch the more wear it will inflict. When it reaches that point you should change your chain.


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## cbcbd (Oct 8, 2008)

bvibert said:


> Some good info on this page:
> http://www.sheldonbrown.com/chains.html


Good link... that basically has it all... you may close the thread


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## bvibert (Oct 8, 2008)

cbcbd said:


> Good link... that basically has it all... you may close the thread



I know, I stopped typing once I found that link.   Sheldon really was the man...


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## MR. evil (Oct 8, 2008)

I ussually replace my chain once to twice a year.


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## cbcbd (Oct 8, 2008)

bvibert said:


> I know, I stopped typing once I found that link.   Sheldon really was the man...


He certainly was  RIP


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## tjf67 (Oct 8, 2008)

I am a firm believer in "dont do a thing if it aint broken".  I dont even know how much a chain costs.  
Some people like tinkering and thats fine.  I personally dont.

Who spends less in the long run?  Dont know.


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## Charlie Schuessler (Oct 14, 2008)

For road riding, some follow the 1,000-mile rule of thumb, it works if you keep the drive train clean (wiping down after rides and regularly lubing).  I tend to keep the drive trains clean so I use a Park Chain Measuring tool to determine the chain "Stretch," however it boils down to shifting mostly.  MTB is harder to keep the drive train clean so I change it when shifting starts to feel different.  And if the shifting is still not right it's time to change the front rings and rear cassette accordingly.  Replacement parts may be seemingly expensive however I find the replacement work is easy.


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## marcski (Oct 14, 2008)

Interesting.  I kind of agree that if it ain't broken, don't fix it.  I have about 4500 miles on my road bike now and my LBS told me to change the chain once at about 2000-2500 miles, he said at that point, it was about 1/2 way stretched out.  

My drivetrain on the road bike is nice and tight.  I think it will last at least another 2500 miles.  (at least I hope.)

With the mtn bike, I think I also am on the 2nd chain.  Original Cassette and original front rings.  This is the 4th season on the bike.


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## bvibert (May 6, 2009)

I'm generally the kind of guy that doesn't fix it if it isn't broken, but I don't buy into that with my MTB chain.  When I go out to ride I want to ride, not fix stuff on the side of the trail, or worse get injured when the chain lets go while muscling up a hard climb or something.  I'm a big guy with pretty strong legs, I put a lot of stress on my chain, I need to know that it's going to hang in there for me.

The chain is a wear item and needs to be replaced periodically, simple as that.  If you replace it regularly, before it stretches too much, then you'll extend the life of your cassette and chain rings too.


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## gorgonzola (May 6, 2009)

alot depends on where and how you ride - i'm definately a "masher" (working towards becoming more of a "spinner") so i'm very hard on the drivetrain. yearly at least for me for the chain, cassette on this bike started getting funky after almost 2 seasons.

this for mtb - no spandex for me =P


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## Talisman (May 6, 2009)

Measuring the chain is only part of the story with a mtn bike.  When you have too many 'gritty' miles on a chain, cassette and sprockets chain suck starts to become frequent it is time to replace irrespective of the chain measurement.  I do believe 'spinners' get more miles on their chains and spokes 'mashers'.

The single speed people don't seem to have as many of these discussions.


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