I’m going to cut join the rear derailleur Di2 wire to get a perfect length so i’ll re-enforce the underBB area of the cable when i do that, which will also let the std cable frame exit clamps hold it properly (bare cable is too small a diameter currently)
I’m also machining a custom steerer/stem top cap, that uses a Hope Head Doctor style clamp arrangement but that holds the Di2 battery pack hidden below in the steerer tube! Hopefully for full integrated looking shifting.
Have decided that drilling handle bars for the wire to the shifter is a step too far (carbon bars) but will use heli-tape to hold the small wire tight and neat to the underside of the bar, so should be pretty invisible once installed.
(i’m also reverse engineering the Di2 communications protocol (things to do on a rainy day eh! ) as i thought that might open up some interesting future possibilities……