Wow! I thought I was being daring trying a pair of 400mm bars on my DF bike. 390mm is narrow.I have tried 440mm, 420mm and now I have 390mm. It seems like most go wide enough to clear their knees or thighs and turn them down for a bit of aero, and the 390mm bars are a bit too narrow for my legs to fit so the 420mm are what I would do next if I were to put on another pair of drop or flared bars. I have also tried a few bullhorns which were ok, but dropped or flared is better IMO.
You mean bullhorn-like?My S40 has 420 Crononero with the ends sticking up. Not very aero, but for me, aero just means breathing. Downward-pointing ends catch my thighs. How can anybody manage with upward-pointing ends?