If one's focus is to improve speed and distance, I think a more effective place to start on a bike is by cleaning up the wake of the rider with a rear fairing. The frontal area of the bike itself is relatively small, and the frontal area of the rider tends toward a rounded shape, but it's the turbulence off the backside that is largest and really slows a person down.
Put another way, an object with low turbulence has low drag, and frontal area is rarely the largest contributor to it. E.g., a brick with only a nose-cone will never have as low a drag as a brick with only a smooth tapered tail-cone.