Originally Posted by
brawlo
From there, you can look at tread types and pressures, but when comparing red apples with green apples, the 23-26mm range that the pros use is where it's at for overall fast riding purposes.
If you're a professional bicyclist trying to win races, then you should definitely follow this recommendation.
If you're a recreational cyclist with 25+mm of spacers under your stem and a 2300g Deep V wheelset who doesn't regularly ride in a 25+mph pace line, the tire size you pick probably doesn't matter so much. A wide, fast-rolling tire like the 700x32 Vittoria Voyager Hyper might increase comfort noticeably while not being terribly slower than a 700x25 training tire...