Don't disagree palincss, as noted earlier I run 28 & 32 cm, with the former on 700c rims and latter 650b rims on my custom single and tandem, the days of skinny tires are long long behind me. When we moved from 28cm 700c on our first tandem to 32cm 650b on our second custom tandem we noticed both more comfort on chip seal and rootlet trails but also additional speed, but "weight = speed" was to explain the reason behind the information listed on the tires above and give some reason to the selections, note the word "if".

But there is speed and then there is speed, while recreational riders are running wide tires, you don't see 32cm, let alone 38 & 43 cm tires in the Tour de France (the really wide stuff greatly favored in Bicycle Quarterly and probably rightly so for paved, gravel and dirt/sand riding, and now I think I with tires approaching and over 50cm?). I think there is a limit to the bigger, lower pressure tire being faster, as if there were any advantage to them for professional racers then the racers would race on them considering that they've tried everything else to get an edge from light weight bikes to drugged bodies, unless there's some restriction on the size of tires to be raced on, so you're preaching to the choir as far as non-racer riding with larger lower pressure tires.