TonyMTL

Just the bullhorns for now, my training environment wouldn’t really be safe for aero bars.

I’ve seen people connecting small “thumb shifters” to the tip of the bullhorn right under where the brake comes out of the bar end, but generally that would imply a slightly different bar end hand postiion due to the shifter being oriented forward (like aero bar bar-end shifters) which is not the position I’m looking for (less stable during acceleration).

STI and DI2 shifters have the benefit allowing you to leave your hands right on BOTH the accessible brake lever positions (either side bar or bar end) and simply switching with your tumb, it’s a lot safer for training/road riding.