yes and no. depends on your definition of "fit" --I ride around 2k miles a year (and yes, I know that's low by some standards), consider myself "fit," and a 39x25 doesn't work for me on roads like High Grade and Evans. I ride a 34x25 on the steep stuff around here (which, to be fair, thanks to slowplows, only approaches 10-12% for any length of time. Otherwise it's all 6-8% max). I'm also a 190lb clyde-light.

39x25 for the 27mi, 7k ft slog up Evans would be awful, at least for my knees.


FL, though, 11-28 on a standard should be plenty all day, every day.