CoogansBluff

Got a road bike about 3-3 1/2 years ago. Was told that first year to replace the chain every 2,000-3,000 miles, something like that. And that if I didn't, it would wear out the sprocket, crank. And since chain is the least expensive, better to sacrifice a decent chain for the long-term good of the more expensive stuff that an older chain will ruin. OK, so started doing that.

Then, sometimes with a new chain, it would skip a little, and so some folks on here who work in bike shops say whenever you buy a new chain, buy a new sprocket too. I didn't follow that advice. Found that the new chain would slowly take the shape of the old sprocket, or for whatever reason, it would start working better.

Now, I can't get a new sprocket because of global supply issues. Was told by bike shop just to stay with old chain and sprocket as long as I could hold out. Now, whole drive chain is working as well as ever. Except for the chain coming off every 10 rides or so, everything seems fine. No skipping, no problems. I don't know how many miles I'm into this chain, but it's probably 6,000.

And finally, I've had a hybrid bike for probably 8 years now. I've never gotten a new chain. I don't know how many miles it has on it. Not as much as my road bike because the old hybrid is in semi-retirement.

So why should I buy so many new chains?

Koyote

You answered the question in your first paragraph.

Racing Dan

There is no One right solution, but, the longer you wait, the more likely "new chain skip" is. I betting it is true a worn chain wears more on the cogs. Reason being a worn chain develops uneven distance between the rollers, gradually shifting the load to only half the rollers/teeth.

c_m_shooter

Once there is any measurable wear they need to be changed as a set, just run them til gone. Chains are cheap unless you have a new high end bike, I find a $10-$20 dollar chain once a year makes the rest of the driveline last indefinately.

shelbyfv

OP, this isn't complicated but you got some incomplete info as to when the chain should be replaced. Change it based on actual wear, rather than mileage or age. You will have to measure it, either with a ruler or a chain checker gadget. Both have their proponents, Google it. Change your cassette when a new chain skips or otherwise acts up. Most people get two or three chains per cassette.

pdlamb

When you've worn the chain and the sprockets down to the point you have to replace the chainrings...

Well, when I did that, I really wished I'd replaced the chain sooner!

Barry2 

I'm betting more chains are cleaned too infrequently, than are changed too soon.

Barry

Iride01 

Measure your chain for wear and you'll know. When I first started coming here a dozen years or so ago, I didn't understand all the chain wearing out controversy I saw in the threads. But I was riding stuff from antiquity and maybe the old beefier chains for a five and six speed rear just lasted forever. Or at least as long as I ever kept any one bike.

Once I got into somewhat more modern times by putting the latest and greatest edition of 105 5800 on my '91 Paramount, I found that my chain wore out in only 5000 miles. So now I'm anxiously awaiting to see if the chain on my Tarmac does the same. But so far at 4K it isn't showing any wear yet. Maybe I baby this one and lube it more or something.

You do know how to check your chain for wear don't you? Either with a metal scale or tape or a chain checker tool.

smashndash

I'll also add that many people are using unnecessarily sticky lubes for their bikes. I initially used basic Finish Line Dry Teflon tube and that gunked up like crazy. Probably also because I never wiped down after lubing. I also literally never cleaned my chain. Mechanic said my chain was gone after 1800 miles.

I've since switched to MSW and chains basically last indefinitely. I've got a CC-4 to confirm. https://zerofrictioncycling.com.au/wax-instructions/ ZFC says 10,000 to 40,000km is the expected range. That's upto 24,000 miles. Twice as many as I've ridden on this bike, ever.

The muc-off oil I use for my outdoor commuter in rainy wisconsin is also super sticky - great for storing in the rain. horrible for a "nice" bike.

msu2001la

A Park Tools CC-4 is a $15 solution to this question.

wolfchild

Chain wear depends on your riding style and the weather condition that you're riding in.

Random11

The OP raises a good question. I replace my chain when my chain gauge shows it's worn, and about every third chain, the new chain skips so I get a new cassette to go with the new chain. But... if the old chain worked fine with the old cassette, why replace the cassette? Just keep using the old chain with the old cassette. The only reason I can envision is that the worn chain is also causing wear on the chainrings. Replace the chain to preserve the chainrings. But I've never replaced a chainring and don't know how much wear an old chain puts on chainrings compared to a new chain. I'm sure someone here can answer that.

If the old cassette worked fine with the old chain, but skips with the new chain, why not just keep using the old chain and the old cassette?

msalvetti

I got one of these last month. My bike is 20+ years old, but there were years I never rode it and I can't even guess how many miles are on it. This year I'm over 1,000 miles and I was sure the chain was probably worn after all this time. Nope, not even 0.5%.

Mark

GlennR

I have the $10 version, works like a charm. I get around 3000 miles before the .5 drops in.

atnyc

How do you determine when you "have to" replace the chainring?

smashndash

Running a chain past 0.5-0.75% increases the risk of snapping a chain. Not a huge deal if you're a small person putting out small watts. But if you value your safety, it's worth it.

Eric S.

It has been my perception that the more expensive drivetrain components have become, the more often the recommendation to replace them. I rode an Ultegra 8sp cassette from 1992 to 2010 - replaced it when a new chain absolutely would not run on it.

Rolla

Based on my shop experience, I would say that most people have never even heard of replacing their chain.

Lazyass

I go by sound. I slowly spin the cranks backwards and listen closely to the sound when the chain links contact the cog teeth. Obviously the chain needs to be clean and lubed and the tune needs to be perfect. If it's quiet and smooth the chain is good and if it's noisy, which it will be if it's worn out, the chain gets replaced. About 3500 miles for me. Cassette gets replaced every other chain unless I break a tooth.

GhostRider62

When the " Except for the chain coming off every 10 rides or so" becomes every 5 rides or you get taken by ambulance to the trauma center, whichever comes first.

Chains skipping or coming off is bad and not safe.

If you properly maintain your drivetrain, unlike the OP, you can get 10,000 miles out of a chain, over 30,000 miles from a cassette and over 60,000 miles from a chainring.

When your chainring teeth look like shark's teeth, they are very worn.

wolfchild

I don't clean my chains or follow any complex chain maintenance procedures. It's a waste of time to remove and clean a chain. One ride on salt covered roads is all it takes to mess up a freshly cleaned chain. All I do is lube it with some WD 40 or motor oil. and replace my chain after every winter.

GhostRider62

I usually replace my chain after winter too. Proper maintenance is hard then. The wear is significantly higher in salty and sandy conditions.

shelbyfv

Some folks do this, replace both at the same time. You might get half again the life before the wear impacts the function. When chains were $15 and cassettes $40, maybe there wasn't a huge difference in the economics. With current prices, it's hard to swallow a $90 cassette that often. I don't know at what point a worn chain begins to damage the chainrings.

indyfabz

When I consulted a LBS about replacing the rings on my touring bike a mechanic used the term “shark’s teeth” to describe their condition.

Sy Reene

Maybe cassettes were this way. One study though finds that, perhaps counterintuitively, that narrower, higher-speed chains are longer lasting than the older ones