[dw_22801]

Hey folks,

I took my bike in to get a tune up, and the guy said the chain is worn and will destroy the teeth? Is that true?

Thanks!

 

[celswick]

Yes. The chain “stretches” and causes
the teeth on your cassette and chainring to wear if you don’t replace the chain.

Then when you finally do replace the chain, the links wont match up with the worn teeth, causing the chain to skip, miss shifts, etc.


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[DtEW]

Yup. And it may already be worn by the worn-out chain to the point where it won’t work right with a new chain. Keep that in mind as to a possible development.

That’s why people keep tabs on the wear state of their chain constantly (after every ride, for some people), so that the amount of wear that the cassette is subjected to is very controlled. And they have various protocols to squeeze the most use from their cassette (AKA the cogset) by switching chains…some people exclusively swap-in new chains, some people swap in chains at various known states of wear.

 

[Jayem]

The first thing to usually go is one of (your favorite?) rear cassette gear. Then your granny-ring up front if you are using more than one ring, from there it progresses to the bigger rings up front.

 

[dw_22801]

Thank a bunch!!

 

[mtbfree]

Hey folks,

I took my bike in to get a tune up, and the guy said the chain is worn and will destroy the teeth? Is that true?

Thanks!

Its true. You can avoid that with changing chains before they get stretched - BUT it can depend on price of cassette - if its cheap you just leave everything until its unrideable then change casette+chain - because price will be cheaper than changing i.e. 3 chains before changing casette
With modern 11,12-speed casette prices you change chains. On old 9 speeds not so much.

 

[mudflap]

A bit of a correction: chains don't actually stretch, they wear. The result is a wee bit longer chain, thus the term "stretch."
Steel doesn't stretch.

 

[J.B. Weld]

A bit of a correction: chains don't actually stretch, they wear. The result is a wee bit longer chain, thus the term "stretch."
Steel doesn't stretch.

Actually steel can stretch. Technically you're right about chains but since they do grow longer as they wear the word "stretch" seems an appropriate description.

 

[Jayem]

A bit of a correction: chains don't actually stretch, they wear. The result is a wee bit longer chain, thus the term "stretch."
Steel doesn't stretch.

A bit of correction:

Stretch means to get longer.

You seem to be confused as to thinking that saying "stretch" implies the metal is elongating. That is only one possible definition of the word. The chain stretching is perfectly fine to describe the situation. It gets longer. I hang up my old chains next to my new ones and they are in fact longer.

 

[prj71]

I replace chain, chainring and cassette all at the same time.

 

[Sparticus]

I've always wondered what exact part(s) is it in a chain that wear in such a way that the entire chain elongates?

If the holes in the side plates enlarged, wouldn't the pins fall out? If the rollers wore, they'd just get bigger/sloppier -- the whole chain wouldn't elongate.

So what actually happens?
=sParty

 

[MSU Alum]

I replace chain, chainring and cassette all at the same time.

It used to be advocated, in the days of 8, 9 and 10 speed cassettes, to just wear the chain until everything is broken. I never thought that was cost effective, but in the days of 12 speed that is definitely not cost effective!
Much better to baby the expensive parts and replace the cheapest item.
I notice degradations in shifting before a chain reaches the magic point at which the measuring gauge indicates stretch. That's when I replace it.

 

[prj71]

It used to be advocated, in the days of 8, 9 and 10 speed cassettes, to just wear the chain until everything is broken. I never thought that was cost effective, but in the days of 12 speed that is definitely not cost effective!
Much better to baby the expensive parts and replace the cheapest item.
I notice degradations in shifting before a chain reaches the magic point at which the measuring gauge indicates stretch. That's when I replace it.

I'm not the best at upkeep on maintenance so that's why I do it that way. On my 2016 hardtail I just replaced the cassette, chain and chainring for the first time in June. Bike had 2500 miles on it. XT 11-46 cassette, KMC chain and Raceface Chainring...~$160 total

 

[MSU Alum]

I'm not the best at upkeep on maintenance so that's why I do it that way. On my 2016 hardtail I just replaced the cassette, chain and chainring for the first time in June. Bike had 2500 miles on it.

Are you running a 9 or 10 speed?

 

[prj71]

Are you running a 9 or 10 speed?

1 x 11 on my hardtail

 

[wschruba]

I've always wondered what exact part(s) is it in a chain that wear in such a way that the entire chain elongates?

If the holes in the side plates enlarged, wouldn't the pins fall out? If the rollers wore, they'd just get bigger/sloppier -- the whole chain wouldn't elongate.

So what actually happens?
=sParty

The bushing (or it's equivalent formed in the inner plates) wears the leading 'side' of the chain pin. You can see it rather easily on a not-terribly-worn chain as one/two--depending on the bushing design--extremely polished areas.

On badly worn chains, the polished area will be straight grooves, the integrated bushings may be badly worn to the point that the rollers are rattling, and the side plates are worn to the point that the chain can be flexed sideways into a rather tight circle compared to a new one. Such a chain, even if it doesn't skip, tends to poor shifting performance, since links would rather flex sideways than follow/pull on i their neighbors.

 

[Sparticus]

The bushing (or it's equivalent formed in the inner plates) wears the leading 'side' of the chain pin. You can see it rather easily on a not-terribly-worn chain as one/two--depending on the bushing design--extremely polished areas.

On badly worn chains, the polished area will be straight grooves, the integrated bushings may be badly worn to the point that the rollers are rattling, and the side plates are worn to the point that the chain can be flexed sideways into a rather tight circle compared to a new one. Such a chain, even if it doesn't skip, tends to poor shifting performance, since links would rather flex sideways than follow/pull on i their neighbors.

I still don't get it but thanks for trying to help me understand.
Seems to me like if the side plates don't elongate, then the whole chain won't lengthen. And I know that's not happening.
Pin rollers can wallow, pins themselves can wear down, in neither case would this cause the chain to lengthen.
Sorry I don't get it. Again, thanks.
=sParty

 

[J.B. Weld]

I still don't get it but thanks for trying to help me understand.
Seems to me like if the side plates don't elongate, then the whole chain won't lengthen. And I know that's not happening.
Pin rollers can wallow, pins themselves can wear down, in neither case would this cause the chain to lengthen.
Sorry I don't get it. Again, thanks.
=sParty

Maybe a picture will help-

 

[Shark]

I'm always surprised when I lay an old chain beside a new chain.
Stretch!

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[J_Westy]

I still don't get it but thanks for trying to help me understand.

Some good articles to review:

How to measure chain wear on an Eagle X0 chain...?

How to measure chain wear on an Eagle X0 chain...? I have been reading that the normal way to measure chain wear on the Eagle 12s chains does not work with the drop in measuring calipers.. I have 2 chains that I rotate every 2000km on my Eagle X0 drivetrain...so far so good...the cassette has...

www.mtbr.com