@ Zach: I think you're correct- when my LBS repaired my bike and the severed cables after my accident, they appear to have slid the new Magura rear brake hose down the wrong (back) opening. Reviewing the Di2 installation manual online, Cervelo does
direct sending the Di2 cable throw the back vertical hole of the bucket. However, that begs the question- where then should the Magura hose (which is a thicker cable than the Di2) go down? It cannot fit through the same hole as Di2, and as you can see from my photo below, it certainly could not go down any of the three ICS3 tubes- which only one (the center) can accommodate the 5mm Di2 and the others too small for even that. When I tried to drag Di2 through with a cable shifter, just one roll of wrapped electrical tape prevented it from fitting down the middle tube. Given that, is it reasonable to suggest that Cervelo never anticipated the (girth of the) 2nd generation of Di2 cable?
@ Jeff: Excellent idea- I never thought of that. However, once I get Di2 up and underneath the bucket, where do I go from there? I cannot wrap that cable up and around the back opening, and the ICS3 tubes are obviously secured in there pretty solid... do I then need to drill through the bucket? Or must I cut open the (larger) center ICS3 cable and thread the cable up through that?
And if so, who can recommend the best solution (drill bit or similar?) to cut through the bucket or cables? I'm obviously nervous about cutting carbon, but even more nervous about splicing Di2. I guess I'm also disappointed that this is the best situation for P5 and Di2.