Howdy,
As I look at pictures of bikes that are racing at Bonneville Salt
Flats,
(and any road race bike in the last 30 years or so), I notice all bikes do
not have any aero fairing on the lower fork legs; as this is a known
smoother of air, by making the rear of any round tube pointed, how come no
one is modifying the lower legs for more speed? It can't be because it's
too hard to do, some of the work I've seen done is incredible....why? Is it
that the pattern of air that is flowing around the front forward edge of
the tire and the disruption of air by the spokes that causes the aero
advantage to be negated? somebody try it before and it didn't work, too
much unsprung weight? anybody seen any wind tunnel data that I could read?
For straight line speed, as at the Salt, how come no one has made the back
of the front fender more fair the same way, with a pointed tail section?
How about gathering the air, as most bikes do now, at the front of the
engine, direct it in a closed tube through the bike and vent it via
converging diverging vents aimed at the hole in the air above and behind
the rider? Bikes punch a fairly dirty hole in the air, any cleaning up
results in more speed, doesn't it? anybody got books that I can go to for
bike aerodynamics? or is it a black art, secrets for the manufacturers only?
John Robinson, Mechanician
Mechanical Engineering University of Wisconsin
1513 University Ave.
Madison, Wi. 53706
608-262-3606
FAX 608-265-2316
Current World Land Speed Record Holder
Bonneville Salt Flats
H/GCC 92 cu.in. 1980 Dodge Colt
131.333 MPH set 1995
136.666 MPH set 1996
140.292 MPH set 2000
144.396 MPH set 2000
///
/// land-speed@autox.team.net mailing list
///
|