I don't know what my flat ground max without wind is. Kinda curious now. I did 0-30 the other night when I was doing some sprints intervals and caught a red light. I know with my 50x11 I spin out at 40 mph at 115 rpm with a tail wind (segment only a hand full of locals hit). But I wish for lower gearing way more often than taller gearing, so I'm not going with a 52 just for that ultra rare occasion.