What Causes a Chain to Come Off?
 

Was out today and had a double whammy. First I flated near the start of ride then near end of ride my chain came off. At first I thought it was the quick link had came apart but one of the links had came off, I actually found the offending link. Didn't look to be damaged at all just inside plate came off, the chain was not wore out but did have close to 5000k on it, oh well guess it was time for a new chain.

Have you ever taken the chain apart using anything other than the quick link for cleaning/repair/anything? I have heard that if you use a chain tool on some of the newer narrower chains that they can pop apart. Just what I think I read somewhere though. I have never had to take off my road chain.

10 speed chains are pretty thin and great care should be used when working with them. I would measure the length carefully and remove only what needs to be removed and do not attempt to add links back. I believe both campy and shimano requires a special pin to install their chains...their not willing to pay the licencing fees to use the the master link technology...but you can buy a 10 speed master link separately.

Cool to know a chain lasted that long. No stretch?

It was still well within the park tool measurements. I am rather hardcore though when it comes to maintaining my drivetrain. Chanin gets cleaned and lubed after every ride.