Is this a cracked chain?
 

Separation around the pin, don't recall seeing this prior. Shimano 11 speed chain, maybe 1500 miles on it. That's a crack/failure, right?

https://i.ibb.co/pKH2mRQ/IMG-2829.jpg

I sure would replace it. I never seen one of my chains do that.

PQD issue that slipped by the QA crew.

That chain is kinda sus. Did you buy it online?

definitely replace. it will fail at the worst possible moment.

"best cheap"

/markp

No, Shimano CN-HG601 chain from the LBS. Stuff happens, I guess. Wasn't getting any skipping at all. Will measure for stretch later just to see but this is going in the bin regardless. Cassette teeth look great on all gears so hopefully I can just replace the chain and that'll be that. Definitely haven't seen a failure like this, I didn't even know this was possible. I was inspecting after lubing and I couldn't recall seeing that prior but given how clean the crack is I was almost wondering if it was by design for some reason and I had just never noticed it. Glad I noticed it at home and didn't break the chain miles and miles from home; I carry a quick link and tool but I'd still prefer to catch something like this at home than find out the hard way on the side of the road.

Thanks guys, now I know it's a failure.

Or use a master link to replace the cracked plate.

Gotta ask - was the chain installed by pushing a pin back through, rather than with a master link?

Yes, and one ride away from a catastrophic failure that could easily send you crashing to the ground.

In my experience its usually a standing sprint up a hill and that top tube hurts as does the pedal in the shin.

OP, sometimes these things happen, could have been a bad temper on the metal, a poor assembly job at the factory or by whoever installed it, for whatever reason, doesn't matter. If you don't know why this one cracked assume the whole chain is compromised and toss it, not worth finding out this was the only link by injuring yourself when another suddenly lets go. Chains are cheap and a new one is a small price for peace of mind.

Yes.

The stock 105 CN-HG600 chain on my bike did that too.

https://cimg8.ibsrv.net/gimg/bikefor...fe09e41a92.jpg

Thanks all, I already ran to REI tonight and grabbed another new CN-HG601 to replace it, will toss it on later this week. Very happy I caught this, I've never broken a chain on the road but have always been terrified of it happening knowing it's gonna happen when I'm under load...it wouldn't be pretty. Must've just cracked because I've only ridden 2x since last inspection. Guess I better start inspecting before every ride.

What the hell are those 2 what look like cuts across the crown of the rim?? Both sides of the chain.

^^^^^ this.

That's just how Campagnolo Zondas are designed at the spokes, nothing to worry about there:

https://i.ibb.co/yXDdKmG/IMG-2837.jpg

I would potentially reach out to Shimano. It is odd that a chain would do that. Glad you got a new one but it is certainly something that is potentially worth look at for warranty.

2 weeks ago a Shimano chain of mine began making a clicking noise while riding. When I returned home I inspected the chain and had a link looking just like 'SoSmellyAir' has in his photo (post #11). Every time it went through the rear DR it make a click. It had a lot of miles on it and I didn't think anymore of it and just threw it away. Now I'm seeing these postings and wondering if I got the tail end of a bad batch. Since I rotate chains every waxing, I'm thinking the chain had at least 5000 miles on it so it's not like it was new, but still in the serviceable range of chains by measurement.

I'll say it.
Chains are too dainty now.

If it is a newish chain that might be a reasonable option. If going that route, I'd measure it for wear and keep an extra close eye on it though.

Yup. Cracked. Replace it.




Now!

Yes, it's cracked. Either replace the whole chain or splice in another quick-link.

But the crack begs the question: why did it happen? Did you soak the chain at some point with a non-petroleum degreaser like "Simple Green?" Prolonged exposure to such cleaners can lead to hydrogen embrittlement and failure.

Just 2-3 rounds of mineral spirits to degrease through the Park Tool chain cleaning tool, let it evaporate (10-15 minutes or so), and hit each pin with a drop of ProLink chain lube...same procedure I've always followed that has never caused issues on any other chain. I also generally don't degrease very often, I usually just add more lube and wipe down since the bike is ridden on nice days.

Only thing I can think is that this latest ride that caused me to clean/lube the chain and notice it was the only dirty ride the bike has ever been through - I am a fair weather rider who only rides on nice, dry sunny days, but I couldn't help myself and let myself ride through tons of snow melt slop the other day. Took five hours to clean/lube/detail every square mm of the bike afterwards, yikes. Next time I'll just resist the temptation and stick to nice days. Only thing I can think of is some piece of nasty grit got right in there just right on this particular ride and it cracked, but I'll never know...gravel/MTB are subjected to far worse conditions on the regular.

Durty:

https://i.ibb.co/zJkXXY2/IMG-2827.jpg

Purty:

https://i.ibb.co/d0B6jQQ/IMG-2830.jpg

Don't over think it. Stuff happens. It is likely a quality control issue that is a rarity. Get a new chain and carry on.

Indeed. My brother has been a mechanic for many years now and said that once 11 speed chains appeared, that's when he started routinely seeing bikes with broken chains come into the shop. Some brands are worse than others but all suffer failures sooner than 10 speed and older chains. You just can't get the same mileage out of the narrow 11 speed chains that you can out of the older stuff. It's why my newest bike has a 10 speed cassette on it.

I may have contributed to the demise of the original chain by letting it soak overnight in Purple degreaser.