Chain wear indicator/when change?

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Sweep
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Chain wear indicator/when change?

Postby Sweep » 12 Sep 2020, 7:41pm

I am pretty careful with checking chain wear these days.

I have a Park chain wear checker which indicates 0.75 and 1 (per cent?) wear and a KMC one which indicates 0.8.

None of my bikes are above 9 speed and these days I tend to change chains when I get 0.75 wear indication, very definitely when the KMC 0.8 slots between the links.

Question - do you change when you get this reading at several points or just at a single one?

I have wondered about this for a while, but particularly today.

I checked an 8 speed chain which I know I put on in July.

I also changed the cassette at pretty much the same time.

The cassette would have gone on fairly soon in July after the chain as I changed the chain when I experienced slipping in a particular cog, and on noting that the chain change didn't solve the issue then changed the cassette as well a few days later.

Problem solved.

I don't know when in July this was.

This bike has not been ridden massively at all since (I have several bikes) and barely at all for four weeks but a check today revealed that the Park chain checker drops between the links at 1 in a SINGLE place. I have only been able to find one place/spread where this happens.

Tests I have done at every other point on the chain show that the checker won't drop between the links at all at the 0.75 marker.

So do you change when you get A SINGLE bad reading for the chain or wait until you get a few?

And what could be going on with this chain?

It seems to have worn, at least at one point, in no time at all.

All I can think of is that I did get a couple of chain drops and may have damaged something in untangling it.

The chain is an SRAM 850 which is my most commonly used chain on 8 speeds and which I always thought pretty decent.

Maybe just a badly made one-off chain/a lemon?
Sweep

Brucey
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Re: Chain wear indicator/when change?

Postby Brucey » 12 Sep 2020, 7:55pm

the difference between one that is a bit knackered in some places and as knackered in lots of places probably isn't much. IME the chain is usually wearing quite quickly by the time it is worn to ~0.75%, so that last 0.1% wear isn't 'worth' as much as (say) the 0.1% wear from 0.2% to 0.3%.

Since the wear rate isn't constant, chains are cheap and the rest of the transmission is expensive (more or less), changing the chain 'early' doesn't cost much so I suggest that you get on and do it. Remember that you can always refit the chain later on if you want to, when the sprockets are too worn to accept a new chain.

Remember also that you can also measure the chain accurately, either by hanging it up or on the bike like this;

https://forum.cyclinguk.org/viewtopic.php?f=5&t=115336

cheers
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mercalia
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Re: Chain wear indicator/when change?

Postby mercalia » 12 Sep 2020, 7:58pm

well these days I just measure 12" of the chain, which is a recomended way by many people here. Does that answer your question, since it ignores single links? what happened to that way of doing it? A pin is 2/16" diameter so need to change when the excess is more than a radius of 1/16". I measure from an edge of a pin. and look how after 12" the edge is to the 1/16 mark. I also use the SRAM 850 chains though still have a few PC41/51 the previous incarnation. I dont trust the Park tool any more. I have a long piece of wood with 2 nails om it that I can wrap the chain around

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531colin
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Re: Chain wear indicator/when change?

Postby 531colin » 12 Sep 2020, 8:48pm

If there are 100 links in the chain and only one is worn, how much cassette/chainring wear will that one worn link produce?
When I commuted through the Yorkshire road salting season, I used to get patchy chain "wear" which I was sure was corrosion (salty water hanging about overnight in the jockey cage). That doesn't seem likely in July, so is your link faulty in some way?
You could cut it out and use a couple of magic links to stitch in a bit of new chain, but is it worth the faff for the price of a chain?

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Sweep
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Re: Chain wear indicator/when change?

Postby Sweep » 13 Sep 2020, 10:32am

Thanks for the replies folks.

I take the general consensus to be that a bad reading on just a single measurement should mean that the chain should be swapped.

(by the by, my one faulty measurement did not pass over the quicklink)

Will replace it so that I am starting from a good place (have very recently replaced the cassette and one or two chainrings) but I am pretty sure this must have been a bum chain from the start - as I said it went on in July, could have been mid/late July, bike hardly ridden for a month early august to early september, longest trips I remember it making were two 20 mile loaded rides to and from a station. Rest of the time has been ridden to the shops now and again. All good weather.

Maybe I'll see if I can find a KMC chain amongst my stocks.
Sweep

mercalia
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Re: Chain wear indicator/when change?

Postby mercalia » 13 Sep 2020, 10:38am

or maybe just get rid of the Park tool :wink: which one do you have by the way?

This is the one I have

https://www.parktool.com/product/chain-checker-cc-2?category=Chain

read what it says ---

CC-2 Features

The CC-2 is compatible with most single-speed and derailleur chains. For 9 and 10-speed chains, replace chain at or just before the 0.75% reading. For 11 and 12-speed chain, replace at or just before the 0.5% reading. For single-speed chains, replace chain at or just before the 1% reading. Check with manufacturer for specific replacement instructions.


not a good one

I see they have other ones Which is the best?

https://www.parktool.com/product/chain-wear-indicator-cc-3-2?category=Chain

https://www.parktool.com/product/chain-checker-cc-4?category=Chain

seems like all say some thing similar

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Sweep
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Re: Chain wear indicator/when change?

Postby Sweep » 13 Sep 2020, 11:12am

nothing wrong with my park checker mercalia - it's the one that shows 0.75 and 1.

I am not disputing its result. The KMC one (though marked for 0.8 generally agrees with it.

I have the CC2 but never use it - willing to sell if someone makes me a decent offer.
Last edited by Sweep on 15 Sep 2020, 4:00am, edited 1 time in total.
Sweep

mercalia
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Re: Chain wear indicator/when change?

Postby mercalia » 13 Sep 2020, 11:55am

out of interest I looked at an old chain. I measure it and it was barely (not even a 1/32") worn but my Park tool said some where between .5 and .75, close to .75 than .5

MikeDee
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Re: Chain wear indicator/when change?

Postby MikeDee » 14 Sep 2020, 3:39pm

The Park CC-4 (or similar) that push the rollers in the same direction, are the only accurate chain checkers (or a ruler).

Brucey
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Re: Chain wear indicator/when change?

Postby Brucey » 14 Sep 2020, 3:47pm

MikeDee wrote:The Park CC-4 (or similar) that push the rollers in the same direction, are the only accurate chain checkers (or a ruler).


er, you are forgetting the method in the link I posted upthread. This is arguably the best of all since it gives you a number, not just a pass/fail indication.

cheers
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Sweep
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Re: Chain wear indicator/when change?

Postby Sweep » 14 Sep 2020, 5:29pm

Well I have fitted a KMC.

If that seems to last well will switch to them once my SRAM stocks are done. I dread to think how few miles the Sram850 had done.
Sweep

Valbrona
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Re: Chain wear indicator/when change?

Postby Valbrona » 15 Sep 2020, 1:17am

I haven't used my Rohloff checker for over a decade.

It supposedly indicates at 0.75. However, I was replacing chains as per this indicator only to have them slip.

I am convinced some chain checker indicate when it is too late.
I should coco.

mercalia
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Re: Chain wear indicator/when change?

Postby mercalia » 15 Sep 2020, 10:45am

Brucey wrote:
MikeDee wrote:The Park CC-4 (or similar) that push the rollers in the same direction, are the only accurate chain checkers (or a ruler).


er, you are forgetting the method in the link I posted upthread. This is arguably the best of all since it gives you a number, not just a pass/fail indication.

cheers


you in the end filed down or some thing the teeth of the digital calipers didnt you to make sure your measurements were accurate and not measuring the wrong curvature?

mercalia
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Re: Chain wear indicator/when change?

Postby mercalia » 15 Sep 2020, 10:46am

Sweep wrote:Well I have fitted a KMC.

If that seems to last well will switch to them once my SRAM stocks are done. I dread to think how few miles the Sram850 had done.


which KMC chain is that?

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Sweep
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Re: Chain wear indicator/when change?

Postby Sweep » 15 Sep 2020, 10:52am

Z8.3 I think
Sweep