Broken chain link
- Thread starter Mctommyd
- Start date
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Yellow Saddle
Guru
- Location
- Loch side.
It is reasonably common on plated chain parts. During the plating process, something called hydrogen embrittlement happens when the plating process goes slightly wrong. That doesn't happen on chains where the plates are treated in a different way than electroplating. The chances are good that you'll find cracks in other plates as well.
But I've just remotely measured your chain for you and it is due for replacement in anyway. May as well buy a new cassette. I'm sure the chain ruined the the on there.
But I've just remotely measured your chain for you and it is due for replacement in anyway. May as well buy a new cassette. I'm sure the chain ruined the the on there.
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
New Chain !
andrew_s
Legendary Member
- Location
- Gloucester
Occasionally there are chains where the heat treatment of the outer side plates wasn't correct, and when the rivet end is expanded into the hole the plate cracks, either immediately or after a relatively short period of use.
Break the chain at the broken link, removing all of it, and check the rest of the chain for similar cracks (radially from the pin out towards the edge).
If you don't find any, put in an extra quick link and carry on.
If you do, it's new chain time, and cassette if a check on the wear suggests it's necessary. Since the chain's clean, you may as well do it properly, with a 12" ruler.
Break the chain at the broken link, removing all of it, and check the rest of the chain for similar cracks (radially from the pin out towards the edge).
If you don't find any, put in an extra quick link and carry on.
If you do, it's new chain time, and cassette if a check on the wear suggests it's necessary. Since the chain's clean, you may as well do it properly, with a 12" ruler.
PaulSB
Squire
- Location
- Chorley, Lancashire
I had exactly the same last Wednesday. Popped in a quick link and continued the ride.
Nigelnightmare
Über Member
I don't use KMC chains anymore after two of them did the same thing after 400-500 miles, damaging the cassette both times.
New Bike !
It's funny ain't it? I've done over 100'000 miles with KMC chains and not one problem.
andrew_s
Legendary Member
- Location
- Gloucester
I've come across cases similar to this, where a chain has several cracked sideplates, for KMC, SRAM, Wipperman, and Shimano chains. I doubt any brand is entirely immune.
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Nigelnightmare
Über Member
I've have had it happen with other brands but not within a thousand miles and both KMC chains went within 500 miles.
They were also worn to +.75 at the time of failure. One was just 3 weeks old and the other was 4 weeks.
The cassette was renewed after each failure/wear, which worked out rather expensive!
They were 9 speed chains if it makes any difference and fitted to a recumbent trike so I'm buying 3 & using 2.5 chains at a time.
I run new chains for 200 miles then clean and lube weekly + lubing around every 100 miles or so.
The latest chains (Wipperman) I'm using are 3yrs old, have done over 9,000 miles and are worn to .5 at the moment.
I find it strange that a lot of reported sideplate breakages are to KMC chains.
Smokin Joe
Squire
- Location
- Bare headed cyclist, Smoker
My own favourite chain, though I have a Shimano at present. Wipperman quick links are the easiest to undo in my experience. The KMC ones are right bastards.
confusedcyclist
Veteran
The KMC ones are easy to open, but only with the tool! That's not helpful away from your tools though!
Ajax Bay
Guru
- Location
- East Devon
I know this is a resurrection of a thread from last spring, in fact just before the world 'collapsed', but I had exactly the same failure over the summer. Well it wasn't a failure because I got home, but something was clicking a bit in the last few miles. On cleaning and inspection I found a link had failed (as in OP image). I replaced the broken link with a quicklink (KMC chain).
After maybe two rides later (?200km) during an 'oil and wipe' manoeuvre, wiping with kitchen towel, I discovered two more links had started to fail, in identical manner.
I have now stopped using KMC chains (9sp) and prefer SRAM ones.
As an aside (to @confusedcyclist ) I think opening quick/power links without a tool is a matter of learned technique.
After maybe two rides later (?200km) during an 'oil and wipe' manoeuvre, wiping with kitchen towel, I discovered two more links had started to fail, in identical manner.
I have now stopped using KMC chains (9sp) and prefer SRAM ones.
As an aside (to @confusedcyclist ) I think opening quick/power links without a tool is a matter of learned technique.
confusedcyclist
Veteran
Yes, there is a way of loosening the links by flexing the quick link and the chain either side of it, but I've noticed it even with the technique it can be infuriatingly difficult on the roadside, especially without a bike stand. Though I'm not sure why one would want to do it at the roadside that often, so it's really a non-issue for me.
