Chain wear gauge - how to use and chain replacement

[aidan.f]

I will mentioned chainsuck from hooked chain ring teeth tends to have a serious effect on rear mechs.

[Ningishzidda]

There are a number of excuses for cyclists having worn chains, sprockets and chainrings.
Suchlike “I have to pay the mortgage”, or “I have to put food on the table”.

A cyclist suffering from an overly worn chainring is no doubt a pauper. Or, an ignoramus who knows nothing of bicycle maintenance.

[Brucey]

A cyclist suffering from an overly worn chainring is no doubt a pauper. Or, an ignoramus who knows nothing of bicycle maintenance.

I don't think Sheldon Brown was either of those things, but he evidently used to run some of his transmissions into the ground like you wouldn't believe.

Possibly he just abhorred waste in any form.

Amongst other things he suggested that if you rode a singlespeed setup with even tooth counts front and rear, you could run the chain out to several percent elongation and that it would carry on working OK. [When chains get really knackered, every other half-link ends up being a different length from the other set of half-links, because of the way chains are constructed and then wear, hence even numbered chainring and sprocket]. 

FWIW I find the sight of so many slightly worn cassettes in the LBS scrap bin a somewhat depressing one; I do wish there was a better (i.e. less wasteful) method of an LBS mechanic sorting out bikes so that the gears definitely won't slip when a new chain is fitted.

BTW chainrings can usually be de-hooked with a file; IME if you run a slightly hooked chainring on a singlespeed/IGH with a new chain, it'll be noisy for a while and then settle down.

cheers

[Ningishzidda]

Oh well.
The only way to prove how much wear a gear system can bear before it finally becomes unrideable is to ride the bike until the system fails.
Make sure to take some train fare with you.

[LittleWheelsandBig]

I recall reading in 'The Bicycle and the Bush' of the dingo fence maintence staff bicycles being used daily and only getting their drivetrains replaced decades after the bikes were built. That was before WW2 though. Modern stuff just doesn't last, of course.

[TPMB12]

Many, many years one chain. Broke mid ride, near a bike shop that is had closed and nobody else around to help. No chain tool and no spare.

Not worth the hassle, replace before it fails I reckon. That's why I'm concerned about my chain since it's easily over the 0.1 "replace" measurement on.the chain gauge.

[Brucey]

re chain breakage;  it seems to me that a few chains will actually fail in service simply 'because they are old' but it is also evident that a lot of chains that break do so because the manufacture is flawed (these chains usually break before they have a chance to wear much) or because the chain has seen horribly corrosive conditions, which encourages cracking.

Of the broken chains I have seen, there have been many more of the latter two sorts than the first sort. Of the 'old chains that have failed' most have shed rollers rather than broken.

It is as well to note that modern chains are built thinner in the side plates and this means they can only be built from stronger steels, with more rivet peening. These stronger steels are (by and large) liable to be less ductile, and more likely to be affected by environmental conditions (e.g. they are more likely to crack if they see winter road salt). The greater peening required to prevent rivets from pulling out can easily leave higher residual stresses in the chain side plates, again increasing the risk of cracking.

So one way or another I think that modern chains are perhaps more likely to break in service, but wear per se isn't necessarily a major factor.

 I think that in view of modern chain reliability, it is an excellent idea to at least have a spare quicklink stashed about the bike somewhere or other; (I tried carrying them in the toolkit, but each of my bikes needs a different quicklink and they are easily lost/omitted from a toolkit). I presently favour stashing the spare quicklink in an accessible spot on the bike e.g.

- in the handlebar end
- under the headset top cap (A-head only)
- inside the stem (ditto)
- inside the seat pin.

Wrapped in a little plastic bag and/or bubble wrap they seem to come to no harm, don't rattle etc when so stashed.

In the event of broken chain (it is usually the outer side plates that fail) it is a question of using a chain tool (or just brute force, screwdriver etc) to remove the broken side plates so that the QL can be installed.

[BTW you can often jam a broken side plate into one of the gaps in a folded multitool; this will often allow enough leverage that it can be removed OK, even if you don't have chain tool.]

cheers

[vorsprung]

I have one of these for chain wear checking



It measures from zero to 1 "percent wear" and I replace at 0.5.  Cassettes seem to last well under this regime
Some really new chains won't fit in the tool as if they are shorter than it expects
I could use a ruler to do this but this tool makes it so very easy.  I can check all my bikes in 2 minutes

[Kim]

I think that in view of modern chain reliability, it is an excellent idea to at least have a spare quicklink stashed about the bike somewhere or other; (I tried carrying them in the toolkit, but each of my bikes needs a different quicklink and they are easily lost/omitted from a toolkit).

I'm of the 'one toolkit per bike' persuasion, as it ensures you have the right spares and specific tools like security skewer keys and 15mm spanners.

But quicklinks come under "too small and light not to carry" (see also: cleat bolts), so if you've got a single toolkit then you might as well carry an assortment.  It might help you save someone else's day.

[Ningishzidda]

Sixteen quid !! 

I'll carry on with my tape measure from the pound shop.

10 3/32" over 10 links is time to replace. Sooner if the chain is very dirty.

( Where's the emoticon of the chap rolling around laughing? )

[TPMB12]

I've got 11-25T cassette,  easiest thing to fit would be like for like. No adjustment of gears, chain length just the same number of links as the old chain. Relatively simple fettle, well not for a maintenance newbie but as easy as can be.

My question is what would the issues be with an 11-27T cassette? Just because that's about the closest option I could get and fit this weekend. What gear adjustment will be needed? Seriously, I don't know since my only adjustment I've made has been very minor and possibly luck with very little judgement or knowledge involved

The other thing, would the 11-27T have a noticeable effect? With a 50-34T chainring I'm guessing it's a little easier uphill. In tend to stick in the 50T so with the 27T it'll be slightly better since I often wish for an easier gear with the 50 chainring so I don't have to drop to the smaller chainring.

What's your opinion? Easy adjustment of gears if I go for the 27T cassette option?

[frankly frankie]

Issues - probably none.  Noticeable - almost certainly yes.

Given the cost of a replacement cassette I now regard the chain as extremely disposable, I wouldn't even waste my time measuring anything, if there's any doubt whatsoever I just replace the chain.  I now replace chains far more frequently than tyres.  And under this regime, cassettes seem to last forever.

[Ningishzidda]

There was a company once who sold bike chain by the roll. Can't remember the name. You just de-linked it a the appropriate length.

http://en.hollandbikeshop.com/bicycle-parts-city-bike/bicycle-chain/bicycle-chain-nexus/kmc-bicycle-chain-z1-narrow-1-2-x-3-32-1speed-roll-50m-brown/

[andrew_s]

Given the cost of a replacement cassette I now regard the chain as extremely disposable

This does depend on what transmission you run.
If it's 7 or 8-speed, a cassette costs hardly any more than a chain, at least if you watch for offers, so frequent chain replacement works out as the expensive way of operating.

Just think of the running costs of SRAM 1x12 transmissions, with cassettes at £200 and chains at £50. Used off road, it wouldn't be difficult to kill a chain in 500 miles, as far as a wear gauge is concerned, which is 10p per mile just for chains.

[Biggsy]

Account for the chainrings as well.

[mattc]

Given the cost of a replacement cassette I now regard the chain as extremely disposable

This does depend on what transmission you run.
If it's 7 or 8-speed, a cassette costs hardly any more than a chain, at least if you watch for offers, so frequent chain replacement works out as the expensive way of operating.

That's good going! For my 8sp bikes I mostly buy the basic chains from KMc or similar "proper" brands. Have been around #5-6 for quite a few years now. Can you get 8sp cassettes that cheaply?

Just think of the running costs of SRAM 1x12 transmissions, with cassettes at £200 and chains at £50. Used off road, it wouldn't be difficult to kill a chain in 500 miles, as far as a wear gauge is concerned, which is 10p per mile just for chains.

Strewth yes - that's not a small cost, is it??

[Samuel D]

I think the 12-speed SRAM cassette is a good deal more than £200. (That’s probably the last time you’ll hear “good deal” and 12-speeed in the same sentence!)

It’s an astounding amount of money. There’s something obscene about it to my ear.

Like mattc, I prefer 8-speed. One advantage is that, with prices for consumables so low, there’s less need to precisely optimise the chain-to-cassette replacement ratio.

I like the freedom that low maintenance costs give me, even if it’s mostly just a psychological thing. It feels like my bicycle is almost free to ride.

[Ningishzidda]

Racing for money – the latest componentry paid for by your team sponsor which gives you an advantage over the other competitors.
Commuting - Tried and tested reliability proven componentry which you are confident will not fail during the ride.
Audax – Tried and tested reliability proven componentry which you are confident will not fail during the ride.
Touring - Tried and tested reliability proven componentry which you are confident will not fail during the ride.
Popping down the shops - Tried and tested reliability proven componentry which you are confident will not fail during the ride.

[andrew_s]

That's good going! For my 8sp bikes I mostly buy the basic chains from KMc or similar "proper" brands. Have been around #5-6 for quite a few years now. Can you get 8sp cassettes that cheaply?

I generally get chains a bit above base level, since I run them to death (~7,000 miles)
Cassette @ £8.60 (Rose)

7,000 miles costs me approximately £8 for a chain, £9 for a cassette, and £15 for a chainring; total £32.
7,000 miles, changing chains every 1,000 miles (which is roughly what I've found as a checker limit) costs £42 even for base level chains, and assuming that the cassette and chainrings last for ever.

[Samuel D]

What does “death” entail, andrew_s? I am also curious what the gear changes are like after 7,000 miles. Won’t the lateral slop be so great that it hinders changes?

Does it still run smoothly while pedalling along after 7,000 miles?

Interesting strategy. I have also heard of people rotating, say, three chains several times while slowly wearing out a cassette. They claim the overall costs are lower this way, though I struggle to see why.

[Biggsy]

I've done similar to Andrew before, with no deterioration in gear changing noticed.  I call it dead when the chain eventually skips, although you might not want to stretch it that far.

[Kim]

I have also heard of people rotating, say, three chains several times while slowly wearing out a cassette. They claim the overall costs are lower this way, though I struggle to see why.

Recumbent riders do that by default.  While my recumbent chains do last significantly longer than my upwrongs', I suspect that's more to do with how they're loaded and how much road crud they're exposed to.  I also note that barakta somehow managed to wear a recumbent chain to >1% in about 1000 miles of mostly fair-weather cycling.

[rogerzilla]

I find that a chain used on a daily(ish) commuting bike for a year is usually worn enough to have taken the sprocket with it.  On a bike with a Sturmey-Archer hub this is fine, because sprockets are only a few quid, but if you have an XTR rear cassette you will be gnashing your teeth.  Basically, how often you change the chain should depend on the replacement cost of the sprockets (a chainring takes much longer to wear out).  Otherwise, the chain and sprockets can be incredibly worn without any adverse symptoms.

[Biggsy]

I have chainrings expensive enough to influence my policy even though they wear more slowly than rear sprockets.  I am carrying on with the same chain on my everyday-bike, though.

[geoff]

Thread necromancy, after exactly one year (wooh! how strange is that?)

I've just replaced chain/cassette and chainwheel (small of a 39/53 double*) and somehow cut the chain a couple of links too short (Arse! but at least it's 8-speed so not too spendy to get another chain).

Why is it so easy to shorten chains but so hard to lengthen them? Of course, not making it too short in the first place would help!

*I'm not sure what the big one's for...