I just rode stage 13 on the turbo trainer, yikes that is one hell of a final 1 miles climb and the route itself is basically constant gradient changes, i do think i've ever had to shift so much over just 21 miles but i do know my lowest gear was in no way low enough for 29% that hurt. I'm not a fan of TT anyway but this one should be really interesting, will there be bike changes at the start of the climb or just ride the whole thing on their road bikes.