Awhile back I converted from a Ultegra triple to an Ultegra standard double (deciding to replace the chain at the same time). Ever since then I've had problems with periodic chain drop (when shifting from big to small, usually with no tension at all, a bit of tension, i.e on a smal hill and the problem wouldn't occur). I replaced the FD to the Ultegra short derailleur setup, problem persists. I then switched to the short Ultegra RD, problem persists. I adjusted the height and angle of the FD until they were just perfect, and still the problem persisted. The chain was also rather noisy on the small ring. I checked every link of the chain and they all looked just fine.

Well finally I decided to give a KMCDX10 a try. Today was my first day out with it. Shifting is even smoother than with the Ultegra chain (part of why I didn't suspect the chain was the shifting was generally very smooth). Chain is also much quieter and smoother. Best of all, chain didn't even come close to dropping off today.

Now, don't get me wrong, I'm sure the 6701 is a fine chain and I just had either a defective one, or I somehow damaged a link when shortened it, or did something else to screw it up. This post is merely for those considering a KMCDX10, if you're on the fence, my vote is to give one a try.

Of course, this was just the first day out with it, but provided there are no issues with it in the short term, KMC will be the brand I use from now on.