Works quite nicely, I have done 3 (mine and friends) and have a 4th to build this winter. Battery will go into seat post with just some wedged shaped foam packing. Junction A can go a couple of different ways, but I mount on the back aspect of stem making it clean from air and easy to access for charging. Everything else is pretty straight forward and easy if you are used to threading cables in these frames. I use long pieces of brake liner that fit perfectly over DI2 connectors, a couple of wraps of electrical tape and thread away. Happy to post/send pics if needed.

Thank you so much! I'll pm you with a couple more if you don't mind

Got it, easier to send pics through email.

For the thread the A junction box decision may have some limits/opportunity depending on stem (near/far/low/high...). Slight mods of the stem cover (non structural) can yield some space and also have some riding mates running Junction A out of their Bento. I have done this on a a Felt IA also yields a clean and easily accessible solution. You can also bury these in frame if you don't mind some fiddling for charging, several options there usually just need some longer cables.

Can you cc in the emails with the pics? I'm building a sc with di2 very soon. I'll pm you my email address

ok i think ill put it right on the top of the cable cover for easy access for charging and such. good thing is those are the cheapest to re-order if i mess those up!

Yeah works well and to be clear I should have said mono spacer versus stem. Things get tight if you have a 25mm spacer or less for a vertical mount of junction A. I have a mid far stem, but have done this with low far as well.

What do you use to mount the junction box on the risers or cover?

Anything holding the junction box b in your frame in place?

Lots of choices for mounting "A" on mono spacer. 1) Velcro direct without mount hardware. 2) Epoxy mount piece to back of spacer. 3) Nothing; you will have 5 lines coming up from stem into box that can be fed down and create a nice support as box will not fir through cover opening.

I haven't built to all stems so you need to set it up and see for yourself which is best. Here is a pic with widened cover opening to allow box to stay put. As I said in email to OP there are certainty other methods and I have done most of them in builds, but this is where I landed.






cheers

I believe there is another junction box between that and the FD correct? Where exactly is that

Junction B will be down at the BB where you make the 4 connections (from junction A, RD, FD, Battery). No need to secure it, just fish things around crank. You can use plastic clips to wires to minimize rattling, but essentially junction B will be just forward of spindle as I recall. Wires for large frame are roughly 1000 for junction to junction, 800 to battery (I like this long for seat post removal), 600 to RD, 500 or 600 to FD. I sometimes adjust length for price as longer is usually never an issue.