up here we call em cow catchers. ive never built one, but instaled one on a harley. augi gave me the idea to put somthin in my bars. i plan to do that this summer.fairing can be seen in my avatar, but is fairly common. but not o an 86 softail what that one is on.
If you really want a speed machine then fairings really are the way to go! check this video out http://www.youtube.com/watch?v=6FAzcEPMi14 Shows just a few of the worlds fastest bikes. speeds of up to 70mph, now think what it could do with an engine
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.
yup, seems to me that a rear cone without a full streamliner would just be a "scoop"...
imo - when it comes to the vehicle class "bicycle", streamlining is an all-or-none consideration, 'bents being the exception as easily streamlined with a fairing. my lil windshield experiments are great for weather protection, but pretty much useless aerodynamically. i bet my final version is not far from the bike as pictured in my avatar.
but - a full streamliner on a 40-48cc setup would make a good showing in the 50cc motorcycle class...some of these new engines are astounding.