# average chain lifetime?



## feh (Mar 8, 2007)

Starting to think about what components I may buy this off-season...

I have 3300 miles on my chain (original to the bike). I keep it lubed, and it doesn't get ridden in the rain. Also, the ruler says it hasn't stretched.

Keep riding it until I experience problems, or is it nearing the end of its life?

Thanks.


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## LizardKing (Sep 25, 2009)

I believe it's "one of those things."

I had a brand new chain break on the first ride, while I own a SuperCycle that has over 7,000miles and is still on the original chain!


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## andulong (Nov 23, 2006)

I got more than 5,000 miles from my last Ultegra chain and my current KMC has over 4,000 and does not measure any longer than it was originally. I will use it until it is almost 1/16" oversize (12 full links) and replace. I have heard of chain checker devices giving false readings and even experienced it once. A buddy checked my brand new chain and told me that it was almost shot...I didn't argue but also did not replace the chain. Keeping it clean and lubed will prolong it's life.


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## muscleendurance (Jan 11, 2009)

two schools of thought on this one...
ride it so much you need to replace both it and the cassette (cant put a new chain on a worn cassette after a certain pt)
or ride it but replace it more frequently and if your top end components man then you'll probably do this given cassettes are $200 a go, and you can use cheap lower end chains with them.

wear depends on maintenance and riding style (masher or spinner, flats or mountains [more coasting=no chain wear])


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## FBinNY (Jan 24, 2009)

Chain life varies tremendously person to person, and is influences by at least 8 different variables so whatever you get can't really be compared to any average. 

If the chain hasn't stretched when checked with a ruler, and is otherwise still in good condition there's absolutely no reason to stop riding it. The only suggestion I have is to re-measure it making sure to tension it enough to pull all the slack out.

Enjoy your good fortune, and it looks like you might get yet another few thousand miles out if it. an


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## SystemShock (Jun 14, 2008)

*ZOMG... it's gonna BLOW!*

Funny thing... my LBS mechanic _insists_ that I *must* replace my 10-spd chain every 1500 miles, or I'll damage my cassette cogs/wear them out super-fast. He gets all wide-eyed and panicky 'bout it, like the chain is going to explode like a hand grenade or something. :lol:

Part of me wants to call bullsheeite (profit motive n' all that), but... is it at all plausible? :idea:
.


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## C-40 (Feb 4, 2004)

*the long story...*

I'll start by saying that someone does not know how to properly measure a chain if they've used it for 3-4,000 miles and claim it has not elongated. That will never happen. Campy chains will elongate far less than other brands, but they still get longer, eventually. With a Campy chain I use roller spacing and side wear as the measures of a worn-out chain, not elongation. With a Campy chain, left in use for too long, the chain may not have reached the commonly accepted "maximum" of .5%, but the chain can still wear the cogs so badly that a second chain will skip when it's installed. I wore out two cogs in only 4,000 miles using one Campy chain that had less than .2% elongation.

Here's my lengthy info on the subject, that includes chain rotation to get more life from a cassette:

Let’s start with elongation or the more commonly used term “chain stretch”. Chains really do get longer as they are used, but it’s not due to anything stretching, it’s simply the accumulated wear between the pins and the bushings formed into the inner sideplates. It is also the only type of wear that increases the pitch of the chain, beyond its nominal .500 inch. It’s commonly recommended to not allow a chain to elongate more than .5% , which is 1/16 inch per foot or 1/4 inch over four feet of chain. I like to think that 1/4 inch over the full chain length of 52-54 inches is close enough. Where this figure came from, I have no idea. It’s not a bad number, but only relevant to chains that exhibit significant elongation. Some brands will elongate quickly, so adhering to this recommendation might work with those chains (like Shimano). Others will show very little elongation, even after 5,000 miles (Campy is one example). If you wait for a Campy chain to elongate by .5%, you’ll be waiting a long time and causing cog damage long before that much elongation is ever reached. 

The only good way to measure elongation is with a 12 inch or longer scale, a full length comparison with a new chain, or some other properly made gage for measuring length, that does NOT rest against the rollers. The 12 inch scale is most common tool, but the least accurate. Place the end of the scale on the edge of a pin. The pin at the opposite end of the scale will be totally covered when the chain is new. As the chain wears, this pin will begin to “peek out” from under the scale. When half of this pin is exposed, you’ve reached a little more than 1/16” of elongation per foot. Full length comparison with a new chain is not a bad method either, but I have found that some new chains may be up to 1/16” shorter than nominal when new. That amounts to 25% of the ¼ inch that you’re trying to measure. What looks to be .5% elongation may really be .38%.

My tests have proven that cogs can be worn to the point that they will not engage with a new chain (chain skips), even if the only chain used on the (new) cassette never exhibits more than a fraction of the commonly recommended .5% elongation. The culprit for this cog wear is not elongation (change in pitch), but roller wear. Rollers always wear much more than the pins and their mating bushings, regardless of brand.

A well worn roller might have an OD reduced by .006 inch, or about 20 times the wear on the pins. If you’ve ever disassembled a chain link, you’ll see that the roller rides on a bushing, formed into the inner side plates. This is a 2-piece bushing with a gap in the center. A severely worn roller will have a diameter in the center that’s about the same as new (since it never touches the bushing), but an area on both sides, where it contacts the bushing halves, that is much larger. It’s quite easy to see the depth of the wear with the naked eye, since they are so deep. You may find the ID of a roller increased in diameter by .010 inch, which is about 30 times the wear on a pin. When I measured the distance between rollers (inside to inside) on a worn chain (6,000 miles), I found an increase from .200 inch when new to .235- .240. IMO, that chain was worn out to the point it should be tossed at that point. The official recommendation from Campagnolo is to toss a chain when the roller spacing has only increased by .020 inch. IMO, that sells a lot of chains, but is much too conservative. I use dial calipers to measure the distance between rollers, so I can compare the new and used dimensions. Shimano and KMC chains have a significantly longer .210 inch roller spacing, compared to .200 inch for Campy, so that should be taken into account when figuring the roller wear.

The last wear area that can be monitored is the side clearance. When new, you’ll most often find a side clearance in the .004-.008 inch range. With a lot of use, that clearance might increase into to as much as .013 inch or more. If you’re into that range, then the chain will exhibit a lot of side flex that may affect shifting precision. Side clearance is easy to check with feeler gages.

Now that you have some idea of how to monitor chain wear, there’s the more complicated issue of how often to change a chain and when to trash it, in order to maximize cog life. Some people change chains very frequently, probably long before they are fully worn, and get more cog life by doing so. The only problem with this approach is that at some point, a new chain will be installed and chain skip will still occur on one or more of the most worn cogs. The cost of all the chains thrown away in an effort to increase the cog life could easily exceed the price of a new cassette and most likely, it is not the most cost effective approach to chain and cassette management. 

The most cost effective method of managing chains and cassettes is to use at least three and perhaps more chains, in a regular rotation. The idea here is to get some use on all of the chains, before enough cog wear occurs to produce chain skip with the last new chain in the rotation. I like to get the most from my chains and never seem to notice deteriorated shifting from side wear, so I like to use only three chains expecting about 5,000 miles from each (Campy) chain. If I was using some other brand, I’d buy 4 or 5 chains and expect to get about the same 15,000 miles from them. The primary requirement for a practical chain rotation schedule is a reusable link to join the chain. A Campy chain can be joined with the HD-L pin for its first use, but after that, a reusable link is needed. Shimano chains can be joined several times, using the special joining pins, available from Shimano, but I’d probably choose a properly fitting reusable link. You don’t need to log a lot of miles on any one chain on its first use. 1000 miles is plenty, but I tend to use each of three Campy chains at least 2,000 before rotating. Once each chain has some mileage on it, chain skip should never occur when rotating to one of the other partially used chains. Each chain can gradually be used until it reaches one of the dimensional limits for elongation, roller wear or side wear. Some brands will hit the elongation limit first and others may hit the roller or side wear limit, but all brands eventually hit the trash can.


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## Kerry Irons (Feb 25, 2002)

*Plausible*



SystemShock said:


> Funny thing... my LBS mechanic _insists_ that I *must* replace my 10-spd chain every 1500 miles, but... is it at all plausible?


It's plausible, but quite unlikely unless you are riding in very bad conditions and don't properly maintain your chain.


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## waterford853 (Oct 12, 2008)

*1500mi per chain?*

C-40 covered the bases well. That shop guy was wrong. I worked in shops for many years. Our rule of thumb was 2500- 3000mi per chain and you should get a minimum of 10,000 from the cassette. In fact, I have never replaced a cassette on my road or MTB's using this rule (suggesting the 3k rule is conservative). As C-40 stated, you can't rely on stretch alone. You will see considerable slop in the side plates after a few thousand miles, compromising shift performance. You are due.


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## Wheelman55 (Jul 10, 2009)

Cleaning and lubing your drive train should also be part of your regular maintence. Properly maintained chains/cassettes/rd's will far outlast ones that are ignored.


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## samh (May 5, 2004)

*chain faq sticky?*



C-40 said:


> I'll start by saying ...
> 
> Can moderaters turn this into a sticky? very informative and he condensed it into one post. also what wheelman said.


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## Oldteen (Sep 7, 2005)

SystemShock said:


> Funny thing... my LBS mechanic _insists_ that I *must* replace my 10-spd chain every 1500 miles, or I'll damage my cassette cogs/wear them out super-fast. He gets all wide-eyed and panicky 'bout it, like the chain is going to explode like a hand grenade or something. :lol:
> 
> Part of me wants to call bullsheeite (profit motive n' all that), but... is it at all plausible? :idea:
> .


Unless you're riding cross or MTB in the mud I'd throw the BS flag on that one, too. I'm pretty typical avid rider (165# non-racer) & with decent chain care (wipe down & lube every 250-300mi or after wet ride) I get ~4-5k mi out of 10s Ultegra chain.


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## Fogdweller (Mar 26, 2004)

SystemShock said:


> Part of me wants to call bullsheeite (profit motive n' all that), but... is it at all plausible? :idea:
> .


Keep in mind that his cost on a chain is half of yours if he's not stealing from his own shop. I get about 4,000 out of mine and try not to push my luck by running them any longer.


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## wankski (Jul 24, 2005)

yep, i do the chain rotation leaving the removed chain in a jar with kerosene to shake up and leave in there... Only way to get the chain super clean... speeds up and simplifies cleaning too...

wipe it dry, leave it to hang while checking out the bike, install - apply fresh lube - shift thru cogs and wipe down..

quicklink is a god send. Will not go to 11sp without it widely being available.


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## brentster (Jul 12, 2007)

I have 8,000 miles on mine over 2 years and I've probably cleaned it twice through one of those roller brushy things. Otherwise I haven't touched it. It still works like a champ and I'm thinkin I can get another 8 or 10,000 out of it.


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## ServingTruth (Oct 2, 2009)

So many variables from what you consider "shifting fine" to what is chain related wear and what is something else. Keep on riding!


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## C-40 (Feb 4, 2004)

*doubtfull...*



brentster said:


> I have 8,000 miles on mine over 2 years and I've probably cleaned it twice through one of those roller brushy things. Otherwise I haven't touched it. It still works like a champ and I'm thinkin I can get another 8 or 10,000 out of it.


At this point your cassette probably has more than one worn cog that won't mate with a new chain, so you can't do any more damage to it than has already been done. If you haven't checked the elongation, side wear or roller wear, there's no way to predict how long the chain could be used. It may already be elongated by 1% or more, have severly worn rollers and excessive side wear, but look just fine. Continuing to use it can also ruin your chainrings in addition to the cassette. Rather than saving money, you'll spend more replacing the parts that you ruined by using a chain for far too long.


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## brentster (Jul 12, 2007)

C-40 said:


> At this point your cassette probably has more than one worn cog that won't mate with a new chain, so you can't do any more damage to it than has already been done. If you haven't checked the elongation, side wear or roller wear, there's no way to predict how long the chain could be used. It may already be elongated by 1% or more, have severly worn rollers and excessive side wear, but look just fine. Continuing to use it can also ruin your chainrings in addition to the cassette. Rather than saving money, you'll spend more replacing the parts that you ruined by using a chain for far too long.


Thanks for the advice. I'll swap the cassette and chain out.


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## Guppie58 (Oct 24, 2006)

Road Bike = Many miles
Mountain Bike = 1000 miles MAX. Unless you don't race.


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## nor_cal_rider (Dec 18, 2006)

I keep my drivetrain pretty clean and well lubed, and tend to get between 1500 miles and 2500 miles per chain over the years. Sometime in the last 5-7 years I changed my maintenance plan to just replacing the chain when the rear tire gets replaced (coincidentally also pretty close to 1500-2500 miles).


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## brentster (Jul 12, 2007)

This thread cost me $130!!!!!!!!!! 

5 minutes after C-40 suggested that after 8,000 miles it would be a good idea if I replaced my chain and cassette I found Ultegra 6600 for $35 and $80 respectively at Excel Sports on the net. My LBS matched the price and installed them for free.  (+ $5 tip).

The kid measured the chain and it was at the 100% stretched mark.

Thanks all.


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## AJL (Jul 9, 2009)

Thanks C-40 really thoughtful write up!


On a related note - does Park sell a good chain elongation tool (I'm going to buy a couple other things from them, so...).

Thx!


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## FBinNY (Jan 24, 2009)

AJL said:


> ....does Park sell a good chain elongation tool (I'm going to buy a couple other things from them, so...).
> 
> Thx!


The best and most accurate way to measure stretch is with a ruler, preferably 12 inches long. The longer the measured baseline, the more accurate the measurement will be.

Park and most other measurement devices share two serious flaws. 

First they do not isolate pin wear from roller wear, which creates an illusion of greater stretch than is the case.

Second they measure over a short length, creating problems of accuracy and calibration.
If we accept the stretch limit of 0.5% (1/16" over 12", we're talking of .0025' per link, or .005" per inch. Over the 4-5" of the typical tools that's only .020 -.025" (0.5mm) so small errors in tool construction or calibration become very significant. Add to that some unsegregated roller wear and it's easy to see how they so often read high.

Save your dough and buy yourself a nice steel rule which you can use for many other jobs, or if you decide to buy a chain gauge for convenience, cross check it's readings with a ruler, especially as you near the discard point.


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## AJL (Jul 9, 2009)

FBinNY said:


> Park and most other measurement devices share two serious flaws.
> 
> First they do not isolate pin wear from roller wear, which creates an illusion of greater stretch than is the case.
> 
> ...


Thanks FBinNY! 

I looked up the park tool and wondered why it measured using the pins - I guess just because it's more convenient to use (though not very useful after all :lol


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## AJL (Jul 9, 2009)

So now I need a 12" steel ruler and a decent pair of calipers (used to a pair - got 'lost' when I moved in 2000). Took a quick look at Amazon and couldn't find dial calipers accurate to .001" till > $150USD .

There are cheap digital calipers that do the job, but I've always used dial calipers (maybe I need just need to change). Where's a good place to buy decent tools? Normally I'm willing the $$s for good tools, but my budget has been cut this year .


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## freethelemmings (Jul 11, 2009)

FBinNY said:


> Chain life varies tremendously person to person, and is influences by at least 8 different variables so whatever you get can't really be compared to any average.
> 
> If the chain hasn't stretched when checked with a ruler, and is otherwise still in good condition there's absolutely no reason to stop riding it. The only suggestion I have is to re-measure it making sure to tension it enough to pull all the slack out.
> 
> Enjoy your good fortune, and it looks like you might get yet another few thousand miles out if it. an


FBinNY-

I simply love your passion for drivetrains! LOL. I think it's awesome.


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## lyleseven (Nov 15, 2002)

*ebay*



AJL said:


> So now I need a 12" steel ruler and a decent pair of calipers (used to a pair - got 'lost' when I moved in 2000). Took a quick look at Amazon and couldn't find dial calipers accurate to .001" till > $150USD .
> 
> There are cheap digital calipers that do the job, but I've always used dial calipers (maybe I need just need to change). Where's a good place to buy decent tools? Normally I'm willing the $$s for good tools, but my budget has been cut this year .


I find tons of items cheaper than the shops on ebay...


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## lyleseven (Nov 15, 2002)

*ebay*



AJL said:


> So now I need a 12" steel ruler and a decent pair of calipers (used to a pair - got 'lost' when I moved in 2000). Took a quick look at Amazon and couldn't find dial calipers accurate to .001" till > $150USD .
> 
> There are cheap digital calipers that do the job, but I've always used dial calipers (maybe I need just need to change). Where's a good place to buy decent tools? Normally I'm willing the $$s for good tools, but my budget has been cut this year .


I find tons of items cheaper than the shops on ebay...


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## AJL (Jul 9, 2009)

lyleseven said:


> I find tons of items cheaper than the shops on ebay...


Thanks, good idea. I'll probably just get a good 12" SS ruler for now and start with the basics. I'll just gauge roller wear, etc, by visual inspection.


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## thosj (Mar 24, 2010)

*Shimano TL-CN41 Tool*

I hate to drag this old thread up, but C-40's chain treatise is so good I thought this a good spot.

Has anyone used a Shimano TL-CN41 tool? Opinions?

It is pricey. It measures differently than most, say left side of one roller to left side of the other. Sort of difficult to explain, but it's different than most that measure inside to inside of rollers. The end that does the measuring and the inside of the peg that rides on the other end, are both machined and appear to be maybe .020" or .025" over nominal 5", which I guess is near the .5% number, eh? Of course, it measures roller/pin/bushing wear, right?

I'm actually a machinist, so today I'm going to set the tool up and actually MEASURE this length with a dial indicator and a digital readout milling machine, but, of course, no matter, if it's the WRONG method of checking, it really doesn't matter how well the tool is made!

C-40, I hope you see this and weigh in if you've ever seen one of these tools, or anyone, for that matter. It seems to me it would be OK, better than most chain checkers, but, still only measuring over 5".

For what it's worth, I'm starting C-40's chain ritual on 3 bikes today. One with Camp 11 and 3 chains, one with Camp 10 and 5 KMC chains, and soon, one with Camp 10 and 3 Camp chains. In about 6 years I'll have a definitive answer if this works or not!!!! I'm 63, so this might be like "don't start a book with long chapters", but I'm anal enough, so I'm going for it.


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## C-40 (Feb 4, 2004)

*info...*

Any tool that pushes rollers in opposite directions is adding roller wear to elongation. The tool you mentioned still looks like it would do that. but mabybe not.

http://techdocs.shimano.com/media/t.../SI-0031A_TLCN40_en_v1_m56577569830607100.pdf

I don't see the point, when you can buy a 12" machinist scale for a lot less money and do a better job. Lay one end of the scale on the edge of a pin. The pin at the opposite end will be covered, when new. When that pin is exposed by nearly half it's diameter, you've reached .5% elongation. 

With Campy chains, elongation should rarely be an issue. I've never got one to wear even close to .5% before the rollers are shot and the side clearance excessive. If you get a lot of elongation with a Campy chain, the lube or maintenance schedule is inadequate.


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## joker (Jul 22, 2007)

I train on the cheapest shimano chain and cassette combo and just ride them till they start to skip on the cogs then i fling em away , i have my dura ace chain and cassette which only get used on race days , its all good...............


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## thosj (Mar 24, 2010)

C-40 said:


> Any tool that pushes rollers in opposite directions is adding roller wear to elongation. The tool you mentioned still looks like it would do that. but mabybe not.
> QUOTE]
> 
> It doesn't push them in opposite directions. It pushes them in the same direction. Assuming held as in the .pdf, pin 1 is against the right side of a roller, held tightly by forcing the chain UP into pin 2, while pin 3 measures to the right side of a roller 5" away. It's a go, no-go situation, but one MUST hold the chain UP TIGHTLY at pin 2 to force pin 1 into the radius. You can force pin 3 in if you let go of the hold UP against pin 2. A friend came over with his bike and one of these tools telling me he needed a new chain. He was not holding up tightly against pin 2 and FORCING pin 3 in, indicating to him he needed a new chain.
> ...


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## C-40 (Feb 4, 2004)

*well...*

As you described, it's easy to get an incorrect reading if the tool is not used properly. A scale seems simple to me. I've even got a full-length measuring device, with a snug fitting pin at one end and a machinist's scale mounted 53 inches away, to take full length measurements, but I only used it for chain wear tests.


With a Campy chain, I can use calipers with internal tips to measure the increase in roller spacing, or my own home-made plug gage. I ground down a 6mm hex wrench so it will slip between the rollers and use it as a wear gage. With KMC or Shimano chains, I'd use a .250 inch gage since the roller spacing is about .010 inch larger to start with, but the elongation is likely to be .5% or more by the time the rollers are worn.


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## thosj (Mar 24, 2010)

Any idea what a chain marked C VE is? Campagnolo? I just was measuring one, don't remember where I got it or when, against a new KMC, and KMC new was longer over the entire length than this C VE marked chain with 1533 miles. Confirming what you just said, I guess, IF this C VE chain is Camp.


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