Originally Posted by
tbonefitz
Considering these two points, and Jan's assertion that stiffer frames hurt his legs more, maybe the real issue is that the returning force from the bike doesn't go into the back wheel at all, but into the leg, and we get used to the way a bike pushes back on us. So, when we're on bikes that feel like our current bike, we feel (and are) faster because the rate at which this stored power is trying to attack our legs is what we're used to, and our legs mete out power in the right amount to work with our equipment. When on a stiffer bike, the force is returned at a quicker rate, and it is more tiring to fight it. But with time, we'll get used to the spring rate of the stiffer bike, and less stiff bikes will feel "noodly" - and slower.