Bicycle Mechanics - cheap chains wear faster

I replaced my chain this spring, and it only has about 1000 miles on it. My park tool chain checker fits at the .75 mark, but not quite into the 1.0 mark. I checked when I put it on and it didn't fit into either.

It was an SRAM PC 830, which I later discovered that there were better chains. I kept it well oiled and relatively clean, but it seems its almost time to replace it again.

If I do replace it, are there chains that last longer? I was looking at the PC 850 as a heavier chain. I need a 7 speed chain for my trek 7000

Those Park Tool chain go/no-go gages might not be that accurate. Measure using a good 12" ruler or tape measure, see this site, bottom of the page. http://sheldonbrown.com/chains.html

1000 miles seems way too little miles for a chain replacement.

how often it's made clean and well lubricated matters.

when the distance of 12" of new chain measures 12.125" it may be worthy of replacing.

What chainring and sprockets are you using the most? I found my chain life is extended by using gear combos with larger chainrings and sprockets, even at the expense of more angled chain line.

On a mountain triple I was only getting 1000 miles on a chain, until I stopped riding the 32 X 15t and other similar gears and started using the 44 chainring more.

What chainring and sprockets are you using the most? I found my chain life is extended by using gear combos with larger chainrings and sprockets, even at the expense of more angled chain line.

On my daily commute, I use the middle ring on the front and I'm all over the board on the back gears.. usually gravitating toward the smaller rings between stop lights. On my morning exercise ride, I ride the big ring on the front and the larger to medium rings on the back.

I'll have to get a shop ruler (wife will never go for greasy rulers) and measure since my tape measure didn't seem that accurate, but I'm thinking when the go / no go gauge gets to the 1.0 I'll replace it. Does anyone know what the equivalent measurement would be to that?

I'm just guessing on the miles, but I had to replace the chain and rear freewheel after 3500 miles last time. Maybe riding near the beach gets more grit in the chain than I realize.

Cheap chains have more space between rollers and side plates and let in more grit, in addition to possibly being made of softer stuff.

Maybe riding near the beach gets more grit in the chain than I realize.I ride crushed limestone trails. I have had good luck with applying a thick coat of chain wax as well as a little thin oil or prolink. The wax may not lubricate but it keeps out the grit.

yea , but they are cheap so you replace them more often, at lower cost,
because they are cheap.

:P

How many miles did the cassete have on it when you swapped for the new chain? A well worn cassete will wear away at a new chain faster than normal until they fit. If you put the new chain onto a worn cassete that is close to needing its own replacement then that may explain why your chain is going downhill so fast.

Cheap chains have more space between rollers and side plates and let in more grit, in addition to possibly being made of softer stuff.

How much more space? How much softer?

Please supply measurements and Rockwell ratings as needed.

A chain should be replaced when any one foot interval has stretched to 12 1/16 inches (12.0625). There is not a direct comparison between a ruler and a chain checker because some of the wear occurs in the rollers instead of the pin/plate interface. My chains reach 12 1/16/foot at about the same time the Park chain checker reads .75. This way I get at least 5000 miles out of a chain and have never worn a cog enough to cause a chain to skip.
Shimano 7700 chain seem to stretch slightly faster than Campy Record chains. The rollers on a Campy UN 5.9 chain seem to wear slightly faster than on a Shimano 7700 chain.

My rule of thumb is:

Never buy the cheapest chain. Likely too many corners cut.
Never buy the most expensive chain. Too much bump in price for too little gain.
Same with cogs and chainrings, BTW.

How much more space? How much softer?

Please supply measurements and Rockwell ratings as needed.Um, I guess you're right. Without hardness testing we can assume the cheap chains are made of stuff which is just as good, and without measuring tolerances we can assume they're fitted as well as expensive chains.:o

Um, I guess you're right. Without hardness testing we can assume the cheap chains are made of stuff which is just as good, and without measuring tolerances we can assume they're fitted as well as expensive chains.:o

Should we also assume that "lesser" chains made in the same factory are punched out on old, sloppy equipment and made with intentionally inferior materials? I'm just saying that your statement had no merit unless you're experienced in the chain manufacturing industry. AFAIK there's more cost difference in the peening procedures and plating than in the raw materials. It would hardly be worth a manufacturer's time to produce a "sloppy" chain that measured as worn right out of the box. Ever measured a $6 singlespeed chain? They're amazingly precise.

Rockwell? got test equipment , then the cost of bike chains is nothin ..

got 2 Whipperman Bushing type 3/32 chains for my IG hub bikes , the right application ,

bushing rollerchain production started in 1880
.. all there was back in the 5 speed era was Bushing chains ..

Bushingless chains, the inner side plates, are punched thru, more flexible, better derailleur shifting,
but wear is concentrated on the edges of surfaces.
Chain, a drawing, of a simple one, is in Leonardo da Vinci's sketch book :
http://en.wikipedia.org/wiki/File:The_sketch_(drawing)_of_roller_chain,_Leonardo_da_Vinci.jpg (http://en.wikipedia.org/wiki/File:The_sketch_%28drawing%29_of_roller_chain,_Leonardo_da_Vinci.jpg)

I'll have to get a shop ruler (wife will never go for greasy rulers)

I like these metal rules - goes down to 1/64 on the ends.
http://www.amazon.com/Westcott-Beveled-Single-ACM05015-Category/dp/B001HA0462/ref=sr_1_7?ie=UTF8&s=office-products&qid=1281415139&sr=8-7

Sorry, no bike computer, so have no idea of the mileage I get, but I find pc 850s to be worth the couple extra bucks over the 830. They seem to ride quieter and perhaps even shift better out of the box.

How many miles did the cassete have on it when you swapped for the new chain? A well worn cassete will wear away at a new chain faster than normal until they fit. If you put the new chain onto a worn cassete that is close to needing its own replacement then that may explain why your chain is going downhill so fast.

I only put about 20 miles on the new chain while it was skipping on the old freewheel before I replaced it. It had about 3500 miles on it, but it was skipping on the smaller gears.

I guess I'll order the 850 and put it on when I get back, unless anyone has any other recommendations. Oh, and a steel ruler to get good measurements.

I have been running a KMC X9SL gold for about 5,000 miles now, still going strong. They are light, titanium coated (to prevent rust) and they are quiet. I have been happy with mine, I'm hoping to see 10,000 with it, I ride in all conditions, since I commute every day. They are not cheap, at about 50 per, but I HATE HATE HATE seeing ANY rust on my chain, and riding in all weather, you'll see rust even if you dry your chain right after riding. I just can't stand that (OCD a little maybe? ;) ).

Joe

Oh, and I agree about top of the line vs one level down, the line between Dura Ace and Ultegra is a fine one, as is the MTN bike line between XT and XTR. Weight is the main savings at the top end, not that it's not worth saving some weight, but at some point, the cost benefit for the average rider isn't worth it.

Joe

I've always used a 12" precision rule, or my own gage that measures the chain over the full length, to measure elongation. I've put 6,000 miles on a Campy 10 chain and measured about .2% elongation. That does not mean the chain is in good shape. The roller were shot and the side clearance nearly twice the original amount. A Shimano or KMC will elongate many times faster.

For those asking about chain dimensions, here are some facts. The side clearance is easily measured with feeler gages. A new chain will have a clearance in the range of .004-.008 inch, when new. KMC chains tend to be the loosest, when new. The roller diameter and clearances are not the same between brands. Campy chains will have a space between the rollers of about .200 inch when new, while Shimano and KMC may measure .210-.215. That's why a chain checker will show those chains to have about .25% wear when new, but they are not worn. It's also why chain checkers are so worthless. Even if you subtract the initial false wear, there's more roller wear added as the chain elongates and the roller wear can be as large as the true elongation. The result is a reading that can be twice the actual elongation.

Wow, I guess I wasted my money on that chain checker. It seemed like it would be an easy tool to use quickly.

I'll just have to get a good ruler I can use accurately and measure.

I've alwasy used a 12" precision rule, or my own gage that measures the chain over the full length, to measure elongation. I've put 6,000 miles on a Campy 10 chain and measured about .2% elongation. That does not mean the chain is in good shape. The roller were shot and the side clearance nearly twice the original amount. A Shimano or KMC will elongate many times faster.

For those asking about chain dimensions, here are some facts. The side clearance is easily measured with feeler gages. A new chain will have a clearance in the range of .004-.008 inch, when new. KMC chains tend to be the loosest, when new. The roller diameter and clearances are not the same between brands. Campy chains will have a space between the rollers of about .200 inch when new, while Shimano and KMC may measure .210-.215. That's why a chain checker will show those chains to have about .25% wear when new, but they are not worn. It's also why chain checkers are so worthless. Even if you subtract the initial false wear, there's more roller wear added as the chain elongates and the roller wear can be as large as the true elongation. The result is a reading that can be twice the actual elongation.

?? Why would a campy chain elongate at a slower rate? Especially since you just lumped a Dura Ace, and A KMC 9sl gold ti, in with a 105/Tiagra level chain, and a KMC 8 speed.
Does the name stamped on the box make it magic? ;)

?? Why would a campy chain elongate at a slower rate? Especially since you just lumped a Dura Ace, and A KMC 9sl gold ti, in with a 105/Tiagra level chain, and a KMC 8 speed.
Does the name stamped on the box make it magic? ;)


FWIW, I'm a mechanical engineer. I've been wrenching on bikes for 25 years and riding Campy for the last 15.

I mentioned Shimano and KMC chains. I did not mention the speed or the model. I've tested the Campy 10 speed chain against a DA 7800 10 speed chain and a KMC DX10SC.

The reason that Campy chains elongate at a much lower rate is due to the hardness of the pins and inner plates. Elongation occurs from the wear on the pin and the bushing formed into the inner plates. I've used many Campy chains over 15 years and never got one to elongate more than .2%. I had to use a precision gage that measured the whole 53 inch chain length to come up with that figure. The elongation was so small that the chain looked almost new over only 12 inches.

The fact that the chains don't elongate very much does not mean they don't wear out. The rollers wear over 6,000 miles was many times greater than the wear on the pin and so was the side wear. I'd never use another chain for quite that long again, unless is was one of the chains in a 3-chain rotation. If a single chain is left in use for that long, you may encounter chain skip when a second new chain is installed (I did). The way to avoid that is to rotate among 3 chains and never let any one of them become more than half worn before changing to another. The idea is for all the chains to be similarly worn. Then you will not get new-chain skip.

I only put about 20 miles on the new chain while it was skipping on the old freewheel before I replaced it. It had about 3500 miles on it, but it was skipping on the smaller gears.

So this latest issue is occuring with a new cassete and a 20 mile chain? That is odd since the chain would not "wear in" to the old cassete that quickly. What you have now SHOULD be good. So I can only assume that the cheap chain is softer or the plates are not formed as well so there's less bearing area and the plates are thus wearing faster.


It occurse to me that what DaveSSS found with the Campy chain wearing out mostly at the rollers is a good reason why the Park style tool is actually not a bad option in some ways. It may not measure the pin to bushing wear like a ruler on the outside does but it DOES take into account the total wear of the pin to bushing and roller. So the question then is how important is wear in the rollers? Roller wear does not change the pitch distance but it does affect how deep the chain attempts to seat..... Hmmmmm... I just answered my own question. Roller wear is equally as important since when the rollers wear the chain pin centerlines will attempt to seat deeper in the sprocket teeth gullets. That will put the pins lower on the sprockets than the designed pitch line and excess pressure will thus be put on the teeth causing rapid wear. So we come back to the Park Tools checker. Yes it measures between the rollers but the rollers are as much a factor in correct chain fit as the pin spacing. So in a way using the Park checker is just as, if not more valid as using a ruler to check the pitch wear.

So this latest issue is occuring with a new cassete and a 20 mile chain? That is odd since the chain would not "wear in" to the old cassete that quickly. What you have now SHOULD be good. So I can only assume that the cheap chain is softer or the plates are not formed as well so there's less bearing area and the plates are thus wearing faster.

No, about 1000 miles on both. Sorry, I misread the question. I put on a new chain at about 3500 miles, and then it was skipping. About 20 miles later I put on a new freewheel.

About roller wear. Since Campy chains don't elongate much, if adequately lubed, the rollers provide the guidance for when to trash a chain. If I'm using 3 chains in a rotation, I will take each one off about the time the spacer between the rollers reaches .220 inch which is an .020 increase from new. Campy actually suggests trashing a chain at this point, but they say to use calipers and change the chain when a 5.200 inch length increases to 5.220. Since some of that .020 inch is elongation, the sapce between any two rollers is a little less than .220.

That's a fine suggestion is you're in the business of selling chains and would like to see a customer buy 6 new chains over the life of a cassette. I prefer to use only 3 chains for the same mileage and not toss what are really only half worn chains. The money saved will easily buy a new cassette.

Perhaps a silly question, but did you attempt to readjust the cable tension on your RD after putting on the new chain? As chains stretch, they get a little sloppier as far as adjustment goes and a few barrel adjuster turns lines things back up. When you put on the new chain, you usually need to readjust the RD a little bit to ease off the bouncing.

For skipping with the new chain/old cog set combo, that's fairly normal. The gear you ride in most often will match the wear of chain. If you wait too long to replace your chain, the new chain won't mesh with the old cogs properly and cause skipping when the RD bounces to adjust chain tension or a pin will stick on the top of the tooth rather than dipping into the space between teeth.

20 miles shouldn't have wrecked your new chain though. I would also take a look at the RD hanger to make sure that wasn't bent somewhere along the line.

No, about 1000 miles on both. Sorry, I misread the question. I put on a new chain at about 3500 miles, and then it was skipping. About 20 miles later I put on a new freewheel.

That's actually what I got from your last answer. That the freewheel was changed after 20 miles and that the new combo has only lasted for 1000. Again the 20 miles on the old freewheel should not have worn the chain to the extent that you've only gotten 1000 out of the new combo to now.

It does raise the question about which part has worn to where the system is now shot. Is it all the chain or is the freewheel a cheapie that may not have used the best steel tempered to the optimum hardness and toughness? Maybe the freewheel has worn out prematurely and killed the chain along the way rather than the other way around.


DaveSSS, getting back to our little side tracking.... :D From what you're saying about the roller wear in the Campy chain it sounds like the Park style tool is the perfect quick check gauge for that type of wear. It also suggests to me that for normal chains that both the Park tool and a good ruler are needed in combination to check for chain AND roller wear since both types of wear are highly significant to how the chain sits in the sprocket teeth. The ruler to check for elongation wear and the Park tool to double check for roller wear and factor the two together.

The proper tool for checking roller wear is either calipers with internal tips or a simple plug gage. I made a pluge gage from a 6mm hex wrench. I ground it down so it's a blade about .070 inch thick with flats 6mm apart, so it will drop between the rollers. If it drops in, the chain is shot.

The park tool does not tell you how much of the wear is roller wear and how much is elongation, so it's pretty much worthless.

With most chains other than Campy, a 12" rule is good enough. About the time that the chain has .5% elongation, the rollers are pretty well worn too. The .040 roller spacing increase that I came up with is aribitrary, but is does indicate a lot of wear. I found the roller ODs to be about .005 inch smaller and the IDs about .010 inch larger. There's also wear from the roller bushing in that .040 spacing increase.

In my tests I found that DA 7800 chain might go 3500 miles before reaching .5% elongation and the KMC might go to 4,000. If chains are used in groups of 3 or 4, then that .5% elongation value is not so significant. The idea is to change a chain before so much wear occurs that the next new chain skips. Eventually, it will happen no matter how often the chains are changed. If chains with similar wear are always in use, then there is no chance of new-chain skip.

It does raise the question about which part has worn to where the system is now shot. Is it all the chain or is the freewheel a cheapie that may not have used the best steel tempered to the optimum hardness and toughness? Maybe the freewheel has worn out prematurely and killed the chain along the way rather than the other way around.

I replaced it with the same Mega Range set that was on it originally Shimano 14-34, I believe.

I'll get a new chain when I get back in town and see if it skips. I'll also be able to compare the two side by side to see how much elongation I relly have. If it's still good, I'll just have a chain to rotate.

So what type of chain should I get? Whatever the non-bottom grade the LBS has?

I use cheap KMC chains or whatever is on sale. The 8sp on my Heron has 11000 miles on it and shows less than 1/16 wear. I remove and clean the chain every 700 to 750 miles. Since I started using the ultrasonic cleaner my chains have lasted longer.

I got 9,000 miles out of the cheapest nashbar chain you could buy.

Well.. I guess I really need to measure before I do anything then. My chain checker just may have spawned 33+ posts for no valid reason. Won't get to it until next week or the week after with the way my schedule is.

I got a steel rule from Sears yesterday. My chain is barely over 1/32" elongated. I'm guessing my park gauge will fit in there around 1/16" of an inch at it's 1% mark.

However, I measured my 9 speed chain on my new (to me) bike, and it was about 1/8" short of 12". Is there a different rule for 9 speed chains?

You did not measure the 9 speed chain properly. They all have the same 1/2 inch pitch. The only time a chain is short, is when new and even then it's usually not more than 1/16 inch over the entire length.

You did not measure the 9 speed chain properly. They all have the same 1/2 inch pitch. The only time a chain is short, is when new and even then it's usually not more than 1/16 inch over the entire length.

I'll have to try that again.. I surely hope there not enough stretch that it made it to the next link.. hopefully I just measured wrong.

Yea, I re-measured and I think its OK. For some reason it's hard to keep it lined up on that chain for me.

Can someone comment on the cassette and the chain condition?

http://i153.photobucket.com/albums/s233/chandltp/2chandl2010_0822AB.jpg
http://i153.photobucket.com/albums/s233/chandltp/2chandl2010_0822AE.jpg
http://i153.photobucket.com/albums/s233/chandltp/2chandl2010_0822AD.jpg

It's all about the finish of the chain. Nickel case-hardening (Dura Ace) is the most effective, followed by ceramic coating (KMC).