If regulations were dropped they would race with egg shaped bicycles, because of aerodynamics. They are very fast. Google that term, lots of funny pictures. On

If regulations were dropped they would race with egg shaped bicycles, because of aerodynamics. They are very fast. Google that term, lots of funny pictures. On climbs, I don't know how they perform. On descents, I have no idea about their safety. Even without going to those extremes, they need a tradeoff bike between going fast on level roads, climbing, descending, replacing flat tires, overall weight, etc. So something like those NDD bikes with maybe a switch to more extreme shapes on long flat courses.