Or at least 50% of them are...
Did my bi weekly 25 mile road ride this morning and there was a weird noise from the transmission every now and again, like it was jumping from cog to cog. I mainly stayed in the small ring and ignored it; it was making the same noise on Monday too.
When I got back I decided to treat the bike to is bi-annual clean since that might make the gears work better.
As I was cleaning the chain I saw that the connector link only had one side. The other side of it was broken off and the bent bit worn away. I stupidly used the Park Tools wire cutters to cut the remaining side, at which point the tip of the wire cutter broke off.
The thing is, I'm 95% sure that I noticed the broken chain a few weeks ago and made a (not very good) mental note to change the chain.
I don't ride very much, but I think that damn thing has done about 110 miles with just one side of the Powerlink. Shame the bit on the other side wasn't as strong.
I had something similar on my MTB, an annoying clicking as I pedaled up a hill. Kept looking down at the drivetrain but couldn't see anything. Took a better look when I got to the top of the hill and found I had half a quick link holding the chain together, the other half appeared to have snapped in half. That was a KMC 10 speed though, not SRAM