Di2 Rear Derailleur Loses It's Mind

[Mike K.]

I appreciate the input guys but I don't believe it is a chain related problem since it began with a sporadic hesitation felt while pedaling. I wasn't blowing any gears while shifting, the chain never dropped between cogs. I believe when it slipped it was because the derailleur gave too much slack for the selected gear. I supposed I could have tried repogramming but I was livid about the problem and the thought did not cross my mind.

[Ypsylon]

I can feel you, but I think it's important to recognize that it sounds more like a mechanical than an electronical issue. It still might have been the RD, but an electrical part can have mechanical problems as well. If you get your new RD you'll have to programm it, so I guess we'll never know what the original cause was.

The important thing is you get back on the road ASAP and don't become paranoid about anything electrical.

I remember one time I put a new part into a computer and soon after that a different part broke. I was pretty mad my brand new part didn't work right and it took forever to find the real problem because I'd been so focused on the new part.

Not saying this is the same as your case, just as an example how a step backwards and a moment of reconsideration sometimes saves a lot of time in general.

[Mike K.]

Good points Ypsylon!

[HammerTime]

What was the ultimate outcome of this matter?

[Gumgardner]

He switched back to manual shifting like the Gods wanted.

[Mike K.]

He switched back to manual shifting like the Gods wanted.

No way! Outcome was I had a tantrum and returned the derailleur for a replacement-no time to diagnose problem.