Why do chains snap?
 

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[Closed] Why do chains snap?

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Is there anything worse than the feeling of a chain snapping under full load?
Well ebola or James Corden I suppose... but I just had a chain go. KMC 10 speed, under 400 miles, cleaned and lubed. So why did it go? I was ready to blame the quick link but it was 3 links down from there. [s]Luckily[/s] Of course spare links and a Crank Bros minitool sorted it. As was the fact it happened only half a mile from the office so I wandered in, made myself a cuppa and fixed it in the warm.
But why did it break? Surely the tech must be sorted by now?


 
Posted : 31/12/2014 12:17 pm
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Are you a fatty boom boom?


 
Posted : 31/12/2014 12:21 pm
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Pick from the list

a> manufacturing error (it does happen)
b> incorrect installation (probably not in this case as not on a join)
c> cross-chaining/bad side loading during a crunchy or jammed shift
d> other miscellaneous damage (accumulated damage from 'c' or rock impact etc. )
e> pure awesome thigh power!
f> voodoo curse


 
Posted : 31/12/2014 12:24 pm
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I ain't no chubster! Nor a powerhouse. So probably c or f from amedias' list. Still amazed that a normal link went before a quick link.
Hmm, I must become smoother and tune gears betterer.


 
Posted : 31/12/2014 12:29 pm
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It's always lack of correct cleaning and lubrication for me: take bike out of shed, apply oil over existing layer of grit, rust, mud and oil.ride to first steep uphill. boom! at least I make question easy for myself


 
Posted : 31/12/2014 12:33 pm
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my most recent was KMC 9sp.
with a whopping (nearly) 100miles of basically the equivalent of towpath riding.
so I vote (a) above, at least for mine. Not (b) cos it was not a join, (c) may have happened, but come on, 100miles? on brand new chainrings, mech and cassette too? (d) is not going to happen on a sanitised gravel path, (e) no comment. (f) is a possibility. of 3 other friends with the same chain model, 2 also snapped at similar distance, and the one that didn't was the gold bling version.

so (g) potentially a batch of fake chains?

most certainly not a lack of correct cleaning and lubrication in my case. all my snapped chains have been virtually new out of the box on brand new other mechanical drivetrain.


 
Posted : 31/12/2014 1:14 pm
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I had a KMC 10s go last week. The side plate broke across the pin hole, about 80 miles or less after a chainsuck/jam incident. I expect that twisted the link and damaged the plate. First broken chain in 15 years or more, the last one was a lesson in how not to use joining pins. I did replace a chain a while back after getting over a log badly and bending the (single) chain ring, though that could have done similar damage to the chain.

potentially a batch of fake chains?
I can think of easier £20 products to fake : )


 
Posted : 31/12/2014 1:28 pm
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This discussion comes up AAALLLL the time on Clyde forums and it's usually big / fat guys claiming that they have teh awsum power and break stuff. Most chains have a breaking strain of 'quite a lot' so it tends to be abuse that will lead to them breaking.


 
Posted : 31/12/2014 2:43 pm
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I reckon a lot is down to shifting technique, it makes me wince when some folk change gear.


 
Posted : 31/12/2014 2:57 pm
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mainly option "C"

only ever managed "D" myself and I'm a beast (in both #PWR! and size) 😉

I bend sprockets and crank arms far more frequently


 
Posted : 31/12/2014 4:02 pm
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I've only snapped a couple of chains, both times it was due to my incompetent shifting, trying to drop a couple of gears at the same time just as my front wheel comes to a big tree root, that sort of thing. Never bent a sprocket or crank arm. I'd take a bit of convincing that anyone can bend a crank arm just by pedalling unless it's a very beefy rider who's specced something absurdly light.


 
Posted : 31/12/2014 4:27 pm
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Didn't mention pedalling at all. nevermind "just" pedalling Johnners.


 
Posted : 31/12/2014 4:34 pm
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Ive done a few KMC SL chains..... normally on hills just putting down to much 'awesum'power...

uaed to leg press 240kg (6 plates each side total arse to load) regularly in gym.... my love of weightlifting an cycling never really was a harmonious thing.

So user error/under speccing - make mine an 'e'. Not a chubster either 🙂


 
Posted : 31/12/2014 4:54 pm
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just putting down to much 'awesum'power..

*cough*bolleaux*cough*

leg press 240kg

Go you

As a starting point, in the US, a bike can't be sold unless it's chain has a tensile strength of 1800 lbf. That equates to over 800 kg. Material fatigue, user error, bad spannering - perhaps. Putting down the power? Nope. Not without something else contributing.


 
Posted : 31/12/2014 6:03 pm
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Same reason yer banjo snaps...


 
Posted : 31/12/2014 6:12 pm
 gee
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Poor gear shifting is a common reason... Crunch! Just ease up a tad when shifting. IME they either go within 100 miles of new (I've had one chain fail due to a fault in 15 years of racing) or last forever.

GB


 
Posted : 31/12/2014 6:24 pm
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Anyone tried Wipperman chains?

Even after having an epic chain stuck between the ISCG 05 mount and having to hammer the chain out with screwdriver and rock, its still going strong. Used them for the last 7 years, and the quicklink is the best out there, true finger splitting with complete ease. Don't pay any attention to careful shifting, stomping etc etc

I've just bought a 10SX for my 10 speed conversion coming up when I get round to it

http://www.connexchain.com/en/product/connex-10sx.html

Although usually buy the £18 budget ones

http://www.connexchain.com/en/10-speed-chains.html


 
Posted : 31/12/2014 6:30 pm
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Pick from the list

a> manufacturing error (it does happen)
b> incorrect installation (probably not in this case as not on a join)
c> cross-chaining/bad side loading during a crunchy or jammed shift
d> other miscellaneous damage (accumulated damage from 'c' or rock impact etc. )
e> pure awesome thigh power!
f> voodoo curse


g> bad habits acquired from SS meaning you turn to big a gear on hills and change under too much load

never snapped chains before I started riding an SS, I don't even ride the SS very often but its changed my cadence and now I snap them all the time shifting on climbs


 
Posted : 31/12/2014 6:55 pm
 DanW
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On the rare occasions I've snapped a chain it has always been very soon after a dodgy crunchy front mech shift. 1x makes a chain's life so much easier!


 
Posted : 31/12/2014 7:04 pm
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I put the wrong quick link in my banjo.. Makes sense now


 
Posted : 31/12/2014 8:38 pm
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g> bad habits acquired from SS meaning you turn to big a gear on hills and change under too much load

I used to SS as well and I think your right ... I also vaguely rember the proper ss chains were beefier and took more abuse as well.


 
Posted : 31/12/2014 9:24 pm

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