How far to push chain wear

[iwantanewbike]

Two years ago I ran experiments testing a few different chain lubes after a regular weekly/200km degreasing and washing interval. Tests proved that no matter the lube, I still reached 0.75% wear in about 1600km. I then tried no degreasing/washing but lubing when squeaky, however that chain also only lasted ~1600km.

I've always been fairly powerful on the pedals but since busting my ankle a year and a half ago and buying a 'gravel bike', my cycling has taken on a much gentler pace. I now generally ride on the off road tracks or shared paths. Accordingly I now get ~2100km out of a chain before hitting the 0.75% mark. So there is all the proof you need that chain wear is linked to the mechanical abuse it gets rather than its cleaning schedule.

My question: am I changing chains still too soon? To get the chain wear tool to drop between the links I need to apply some force on the pedal to "stretch" the chain a bit (it won't go in by itself). If I try the 1.0% side, it doesn't drop in the links at all even if I force the chain. Can I get away with a bit more mileage? Presumably once it starts to allow the 1.0% side to drop slightly then I shouldn't hold off changing it.

 

[numbnuts]

I think a big factor is how you ride, I sit and spin and can get 6500 miles out of a chain, my maintenance is wash chain in white spirit and WD 40 every other trip

 

[raleighnut]

[QUOTE 4812516, member: 9609"]When I first took up cycling I was getting nearly 2000 mile out of a chain, as I have become much stronger and can power my way up big hills at a descent pace, I am not getting much more that a 1000 mile out of a chain. I do think different lubes do make a difference and regular cleaning and oiling is obviously important. But I am now coming to the conclusion one of the major factors is weak legs v strong legs.

Just a thought on your 'how far to push a chain' question. - continue changing them at 0.75, but keep the old chain, when you eventually fit a new chain and it starts to slip, dig out your old chains and start using them again, they won't slip as they will fit the worn cassette, you will should be able to take them up to 1.25% may be 1.5% without any bother.[/QUOTE]
++++++! always save part-worn (but not knackered) chains

 

[slowmotion]

I bin mine when wear gets above 0.5%.

 

[screenman]

How long would a car engine last without oil?

 

[Yellow Saddle]

How long would a car engine last without oil?

According to youtube, a Mercedes C220 can drive around a track for 19 minutes before the engine blows up. That's pretty long.

 

[Drago]

That is indeed quite a long time for any C class to go without something breaking.

 

[Hugh Manatee]

I think I may be the lone voice in the wilderness here but, I don't ever worry about chain wear. I say this with a few provisos. My kit is quite old, 8 and 9 speed cassettes. The 8 speed stuff especially dates back to a time when components weren't made of cheese. Gears are non-indexed shifting via old XT thumb shifters in friction mode. I need to put a proper 8 speed XT mech back on it to replace the new fangled 9 speed thing on there now as I cannot quite get it to index.

That chain has been on there since I changed the cassette, chain and middle ring in about 2005. This particular bike had very heavy use training for an end to end that didn't end up happening. It had to carry a lot of weight in the form of camping gear etc. I remember thinking at the time I would need to change stuff for the ride as the rear wheel had stopped making a clicking noise as it free wheeled some years previously. I removed the cassette body, decreased it and soaked it in 'diff' oil and it is still in there now.

The other bike is a road bike. It was custom made for me in either 1999 or 2000; I can't remember which. It is still running the original Campagnolo Chorus 9 speed stuff it came with. Cassette, chain, cables; all original. It still indexes perfectly on every shift. There is no jumping or skipping of any kind. The cranks have started to creak a bit but I am having a hard time finding the correct removal tool.

This was an occasional race bike with 39/53 and 12/23 gearing. I used it to build fitness from a very low base for the aborted end to end. My maintenance regime is er, sporadic. I do like my chain cleaner though. I also favour a rapid spinning cadence.

To conclude, I ride it until it all stops working together. My standard test is to remove a sprocket and the middle chainring (or the small ring on the road bike).

I throw it at a brick wall. If it bounces back off; refit to bike and carry on. If it sticks into the wall; sell to a ninja and replace the whole lot. The biggest problem with this is that by the time I am ready to replace, I can no longer find the same stuff for sale. I have a chain wear tool (I bought it for a laugh) but the last time I used it, the whole thing fell down between the links!

I fully understand that the modern stuff is far more wear critical (ooh, there's a thing) and that prices for modern XT and Chorus stuff (is it still in the current ranges?) would perhaps make my method expensive! The manufacturers of chains and cassettes must love it though.

Not the current view I know and quite a long post. Condolences to all in Manchester today.

 

[Yellow Saddle]

The observations that higher torque causes more rapid chain wear are correct. A chain wears at only stages of the chain's travels along it's circular path. Those are at the 12 O'clock to ten-past position on the chainring and, at the 10 to 12 O'clock position on the cassette. These positions are where the chain articulates under tension. It articulates at the 1/2-past position on the chainring and all the way through the RD's chicanery, but wear doesn't happen there because the chain is slack there. This is somewhat different for singlespeeds without spring-loaded chain tensioners, but not much.
The chain essentially has two runs: a tension run and a slack run. During the slack run, the oil flows back into the chain's pressure faces via capillary action. During the tension run, the oil is gradually pushed out of the tension faces, with the chainring articulation position being the chain's driest position. The more torque applied, the quicker the oil is pushed out.

As a chain cycles, it constantly "breathes" oil in and out. This is of course only true if the oil is liquid enough to flow. If the oil becomes gummy or something inappropriate like wax is used, the chain mostly runs dry and wears quickly.

However, hygiene is everything and an open-to-the-elements oily chain is probably the worst position to be for any wear part. A chain that runs in filtered oil without exposure to the elements lasts several thousand times longer than an open chain. This is evident from motorcycles. They have a drive chain open to the elements and an internal timing chain running in engine oil that's filtered. The internal chain lasts as long as the engine, in most cases. The external chain a few thousand miles, in spite of the fact that the external chain is longer, runs over larger sprockets and has O-ring bushing seals.

 

[numbnuts]

[QUOTE 4812530, member: 9609"]are you on a recumbent ? and if so what length is the chain ?[/QUOTE]
No that is on my road bike, recumbent trikes even last longer

 

[Ajax Bay]

My question: am I changing chains still too soon? To get the chain wear tool to drop between the links I need to apply some force on the pedal to "stretch" the chain a bit (it won't go in by itself).. . . . . Can I get away with a bit more mileage? Presumably once it starts to allow the 1.0% side to drop slightly then I shouldn't hold off changing it.

Are you changing chains too soon? Probably not. Since you're making sure that you measure (using the tool) the chain under decent tension, if the 0.75% drops the chain is best changed asap. If you put the new chain on and, under 'powahh', it skips; you have left it too long. If you leave it too long (and certainly if the 1% end drops) the most economic way forward is to put the old chain back on (hence the need to hold onto worn chains) and ride the chain cassette combo till it skips, and then change both. Buy a new cassette and have it ready (with the new (fitted and then removed) chain) so that you do not lose riding time.

I carelessly let the (9 speed) chain I've got on elongate by more than 0.75%, replaced the chain only to find skipping (you need to check this on all but the smallest sprockets btw), so I put the old chain back on. So far the chain has done 4110km and the cassette has done 3867km. But I will replace both before my next long ride - Mille Pennines, even if it hasn't started skipping by then. I don't want to come down hard on my top tube at the critical bend on the Hardknott Pass climb (or on any of the other 'double chevron' climbs).

 

[MontyVeda]

On my most recent cassette, chainrings and chain replacement, I've decided to bin the chain gauge and just run the lot into the ground. I keep the chain well lubed and i'm interested to find out how long everything will last as it wears out harmoniously. It's been a couple of years so far and i reckon it'll work out cheaper in the long run by not replacing slightly stretched chains far too often.

 

[Bodhbh]

++++++! always save part-worn (but not knackered) chains

I used to, but you end up with a box of chains of varying vintage and length - more bike clutter! I'm in the life's too short, run the lot into the ground camp now.

 

[raleighnut]

I used to, but you end up with a box of chains of varying vintage and length - more bike clutter! I'm in the life's too short, run the lot into the ground camp now.

I've donated a few 'part worn' chains to workmates who just use a BSO to get to work when a new chain wouldn't have worked on their freewheel but a used one will mesh happily.

 

[andrew_s]

On my most recent cassette, chainrings and chain replacement, I've decided to bin the chain gauge and just run the lot into the ground. I keep the chain well lubed and i'm interested to find out how long everything will last as it wears out harmoniously. It's been a couple of years so far and i reckon it'll work out cheaper in the long run by not replacing slightly stretched chains far too often.

In my experience, the transmission eventually gets rough enough in the rarely used (in my case) 11 & 13 sprockets that they become even more rarely used, and final demise is either the most used sprocket (18) getting worn enough to allow chain slip, or the rollers wearing thin enough that they crack and fall off.