Originally Posted by
noglider
I have a wild-ass theory that bikes with steep head tubes are designed for quick handling, and moving the rider's weight forward on the bike adds to the effect that the design seeks to achieve. On my racing bikes, I feel as if there's more weight on the front wheel than on my other bikes. But it's just a theory.
Reasonable conclusion, seat tube angle only plays a part, top tube length and the front center dimension while not tied together exclusively work in concert. The FCI, the Italian cycling federation commissioned a study in regard to road race bike design published in the early 80's, I found a translation once, but it became a bad link.
Anyway, it suggested and foretold the " typical Italian race geometry" that persists to this day. Pinarello and Gios were early adopters of the guidance. Shorter top tubes, longer stems, steeper head angles and reduced fork rake.
What I consider the nervous race bike school of design. Fun for the first two hours, fatiguing late in the race. My personal view it has attributed to the nervousness of the pro peloton. Ever compare images of today's pro peloton to say the footage in LeCourse en tete? To me it looks like today's riders cannot ride a straight line to save themselves!
The public's best hope for better is the popularity of the gravel grinder "adventure" bike. In general, more sensible design.