I've ridden thousands of miles fixed gear on chains using that link. I suck at chain repair, changing a chain always takes me way longer than it should, and still have never had a problem with that clip. So they must be pretty idiot proof. I doubt it was cold enough to compomise the steel. My guess would either be a defective link that finally failed or the bike was left somewhere, like a public rack, and something hit the chain hard enough to damage it.


Did the side plate pop off the pins or physically break?