Originally Posted by
SoSmellyAir
Since Di2 shift lever only sends a signal to shift, I am quite sure something can be hacked together to do that and pull a brake cable.
Ultegra Di2 shifters/brakes on an otherwise 105 Di2 groupset probably makes the most sense for a budget rim brake Di2 build, but I was thinking more about OEM spec builds. From that perspective, there doesn't seem to be a lot of mixing/matching from different groupset tiers these days, so I'm wondering if any would even offer a rim brake Di2 build (Ultegra?) - noting that this setup was already a bit of a rare bird these days.