I've been away from internet for two and a half weeks, traveling and camping and hiking at a bunch of national parks out west, and am now in Michigan at my parents' house, and my mom wants her touring bike updated to aero brake levers (not brifters, just switching from road brake levers with exposed cable housing to road brake levers with cable housing routed underneath the handlebar tape). I would also be replacing her current 80mm quill stem with a 60mm quill stem, since her bike's top tube is way too long for her.
My only worry is that cable housing may need to be longer when using aero brake levers and routing cable housing underneath the bar tape, and I don't have any extra cables or housing with me.
So, simple question. Anyone have estimates of how much longer (if any) cable housing needs to be when going from non-aero to aero road brake levers?