I wondered why my gears were a bit clonky on my 9 spd crosser/road bike, and on closer inspection 2 of the side plates had split!!

I’m not one for bad gear shifts neither.. Must be a duff chain I reckon? I’ve never broken a chain before, but breaking it in 2 places on the same chain is quite an achievement (and getting home before noticing…)

There have been a few bad batches of Shimano chains:

http://forum.ctc.org.uk/viewtopic.php?f=18&t=22858

If it’s not massively old, you could try returning it if it looks like a dodgy chain as opposed to you riveting it back together with a rock. 🙂

Interesting, thanks for the link, that sounds like what it is. The metal looks like it has just suffered from fatigue and split.