I have ridden a nice selection of modern bikes over the years. If I am significantly faster on them, it would be a surprise to me. I live in flat Miami, where there is only one significant hill. Maybe on that one hill or in a criterium type situation, I would end up being faster. It would be more of a matter of shifting rather than frame design. I know one thing, I am significantly less comfortable on a modern stiffy bike and I am completely unable to detect a weight difference between a 22 lb machine and an 18 pound machine. I recently set up a friends Pinarello F3 Carbon job for its maiden voyage. The stat book says it weighs 18 pounds. My friend's electronic fish scale gets it at 19.5 lbs without so much as a bottle cage or even a computer. When I lift it, it does seem somewhat, or even significantly lighter than my 21.5 lb machines. Two pounds lighter and the possibility of having the medics fish shards of carbon out of my thighs when the seat post splinters, or worrying about a scratch on the frame that may prove catastrophically fatal. I think not!
I recently turned on a friend to classic bikes. He was a skeptic. He was rather fast on the modern bike and just as fast on the old steel job he restored. The difference is he loves, even cherishes the old one. The modern one he rides on wet days or in tight competition when he fears that he may suffer a fall. After all, a disposable super light bike.... who cares if it self destructs? It's only a purposeful machine, not an object of art to admire.
Garth Libre in Miami Fl.