ELECTRONIC SHIFT UPGRADE PLAN

Sourcing the parts for a Di2 conversion is fairly daunting at first but I have done it successfully before on my Shiv TT (also not a Di2 specific frameset).  Majority of the info we needed was in the Shimano manuals and my preferred approach is summarised by these two diagrams:

So we need to do some investigation to determine:

• Suitable junction box locations (Internal or external)
• Internal or external battery
• Internal / External cabling (or a hybrid)
• Wire lengths

So surely someone has done this before but I can't find a blog or forum post anywhere showing a fully internal upgrade for this bike!   Most of the upgrades were done when Di2 was new and the internal battery was not an option.

I’m really keen for the fully internal battery as the plan was to get cables out of the wind for the aero benefits, less clutter and be comaparable with a 2015 model bike.

The external batteries are clunky and they don't communicate with the newer USB interface / charger I use now and I don’t want to buy the older PC interface and battery charger if I can avoid it.

So I persisted and eventually the main limitation became clear; the seat tube was not open into the bottom bracket cavity!  I quick check of our frame confirmed this area was blocked and I can see how this would deter most people.

Some poking from above and below got me to the same spot at the base of the seat tube suggesting the barrier was very thin.  I fashioned a makeshift 3mm drill extension and with a few seconds on the drill it was through and I could see the shiny alloy bottom bracket tube below!

The barrier layer is indeed very thin so I’m relieved of any concerns about this hole reducing the structural integrity in the frame.  The hole was in the centre of the tube away from the sides where there may be splice connections between the carbon tubes.

With some patience I managed to fish a wire out the bottom to satisfy myself that a full internal setup was possible.

With some 10mm OD x 7mm ID aluminium tube, a 7mm drill and 5 minute epoxy I fashioned a long drill to enlarge the hole sufficiently to pass the 5mm Di2 plugs.

I’m now ready to finalise my Di2 shopping list.