I have a KMC chain which seems oddly stretched even after rather low mileage. The chain and cassette were replaced at the same time, and I only ride in dry, if a bit dusty, conditions. I maybe put 500 miles tops on this chain. And it looks to be pretty stretched. I'll hold off the verdict until I take it to the shop and get it measured with their gauge or something.

In any case I took it off the bike and now I'm missing one plate of the missing link. D'oh! Has anyone had this happen?! My KMC missing link ... went missing! I knew that it was loose and kept track of one of the missing link plates as I guided it off the chainring but the other one .... must have gotten eaten by the rear derailleur or something!! I've been searching the ground for 10 minutes now!

I guess I'll be placing an order for a new chain anyway, and I'll get a 6 pack of missing links while I'm at it.

My first and last (SRAM?) link went AWOL beside the road about 1/2 mile from my house

Hah! Yes. Just had it happen last week. Took chain off one frame a couple weeks ago as part of installing drive train onto a different frame. Distracted by some job-related travel and also by helping some kids with their bikes. Went back to my own and only one side of my connecting link was to be found. Argh! I had a spare link to use, but still...

Some Kmc chains use a roller which is just slightly smaller than other chains which means if you use a guage that drops into the chain to measure the stretch it will not be accurate. To get an accurate measurement you need to measure pin to pin on the outside of the chain.