likely average speed is 26-30mph. We did 25mph on a slightly hilly course at the end of last year without tribars. I have found some clip ons to fit, I use tri bars on my solo tt bike. I've thought of another option, that my commuting wheels have a semi deep section (30mm including breaking surface), 105 hubs, 36 spokes. They might make another compromise between strength and aero and cost if it breaks.