Di2 external wiring
 

I'm thinking about upgrading my bike from 7800 to Di2. My frame doesn't have internal cable routing, so I'll have to use the external wiring setup. Has anybody had any issues with external routing? Any problems with cable nicks or wear that would cause a short in the system over time or things of that nature?

External routing doesn't have any more problems than internal. It just doesn't look as clean.

I was going to run my last bike external wiring and did not see any problems with it. However I bought trek 5.9 with Ultegra DI2. It is the best, I love it and I will never go back to regular shifting nothing beats the DI to you'll be greatly please. Di2 is friggen awesome

The only problem I had with external wiring (in case of Ultegra DI2) was junction box... It needs a bolt hole and my Scott Addict didn't come with one... right now I am using double sided tape to hold it in there but it isn't as sturdy as I would like it to be (lack of surface are for the tape to adhere nicely). Going to bend a plexi around and probably glue a nut on that and tape that to addict bottom bracket so I can screw it on.

Just make sure you plan the cable out to the last detail. Clean the frame to remove all finger marks and dirt. Lots of online tutorials that will teach you. Or bring to LBS for a standardized setup format.

IMHO i wouldn't upgrade to DI with external wiring for aesthetic reasons. It sounds stupid, and caring about what others think is completely worthless in comparison to FLAWLESS shifting, still... theres something about having to adjust a perfectly fine machine to accommodate a strange mechanism that wasn't thought for it. Clean bikes make me smile...

About aesthetic, you guys know there are black or white cable cover for DI2 cabling right? (Granted you have black frame or white...)
Since mine is black bike, hard to notice it is there...
BTW, a little tip after yesterday's fiasco. Give the connector to shifter a little room right around where it is connected so that it doesn't accidentally pull out on major shock situation, pulled through bar tape, etc. Had that happen yesterday on big century and was stumped for 20 minutes... Going to retape it tonight with bit of slack so that doesn't happen next time.

I would like to see external wiring on a steel frame with the cable channel/cover.
I have a steel build frame build coming up, and I'm strongly considering Ultegra Di2.

You might want to use this:

Caflee internal Battery

http://img135.imageshack.us/img135/8117/img4275i.jpg
This is what it will look like.

do you have any less crazy angle shots

no. in case it's not obvious, the bike is upside down. Since the wires are run underneath the downtube you don't really see anything right side up.

I've had an externally-wired setup for over 3 years now. Zero issues.

I would think that the only issue with externally wired Di2 is the looks. For example the install on Pcad's bike is not great.

has it really been out that long?

Yep. Time flies...