As you may remember, my initial thoughts were to route the Di2 wiring through the handlebar, through the stem and then down the fork to the downtube to connect to the internal junction. With having already made the holes for the wiring in the fork, I decided to test the theory by routing the cable. WHAT A NIGHTMARE! I spent hours trying to thread the Di2 wiring using everything from brake cable to string to picture wire. I just could not get the connectors to pass freely through the fork and into the downtube. I used thin picture wire to fish through the two holes in the fork and then connected it to a string which I was able to fish down the downtube with the weight of a nut. After connecting the wire and string, the cable was able to be advanced up to the second hole in the fork. It just wouldn’t go any further. I finally decided to bite the bullet and drill a small hole in the side of the downtube and have the wire route externally to there. In all honesty it looks very nice and possibly gives an even more professional look.