Wings, spoilers, aero stuff on GP bikes?

Discussion in 'Motorcycle Racing' started by Brafield, Oct 29, 2003.

  1. Brafield

    Brafield Guest

    Well over 30 years ago, Phil Read's MV had small "canard" fins fitted
    to the fairing sides. That has been the only obvious bit of car-style
    aero work I've seen on bikes. What else have people tried? I suspect
    that a 45-deg leaning bike does NOT want any more downforce applied at
    45 degs. Do the factory GP bikes use anything that's no obvious and
    out in the airstream?

    Another related question: in the 1960's it was common on UK and
    European drag bikes to see full "dustbin" fairings that enclosed the
    front wheel and forks, down to inches from the road (I think even some
    Manx racers like Geoff Duke used them). Why have they disappeared?

    Cheers
     
    Brafield, Oct 29, 2003
    #1
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  2. Brafield

    Dan Carter Guest

    No one has yet used my idea of a wing attached to the rider's butt. Ass
    positioning would enable him to direct the downforce vector optimally to
    improve grip. And, some cocktail napkin physics suggests that less lean
    would be required for a given turn radius and speed, so the rear tire
    could have a flatter profile. With proper hip thrusting (various
    training regimens come to mind) he could adjust the wing's angle of
    attack, ala Jim Hall's Chaparral 2D, for high downforce in turns and low
    drag on straights. You read it here first.
     
    Dan Carter, Oct 29, 2003
    #2
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  3. Brafield

    Brafield Guest

    **** Thanks, guys. I am very impressed by the polite and factual
    responses on this NG ---- very helpful. Some NG's, I dare not ask a
    question in case some 'heavy' stomps on me! *****l
     
    Brafield, Oct 30, 2003
    #3
  4. Another reason _could_ be that anyone except the shortest riders wouldn't be
    able to get the head down without moving backwards, the helmet would crash
    with the wind shield. Works every time.
     
    Morten Becker-Eriksen, Oct 30, 2003
    #4
  5. Brafield

    jim Guest


    Full fairings or "dustbins" were common in the mid '50's.
    Really caused speeds to jump. But FIM banned in 1958.
    And aerodynamic aides have been banned since then
     
    jim, Oct 31, 2003
    #5
  6. Brafield

    Julian Bond Guest

    I've said this before but I would love to see some formula libre club
    racing series that was genuinely "run-what-you-brung". Let's have two
    rules. 1)two wheels 2)wheel driven, and that's it. If you can get your
    fully recumbent drop tank with the turbo-GSXR engine round the track
    faster than a TZ250 good luck to you. Of course top speeds would make
    this horribly dangerous.

    In 1958, restricting the aero designs was probably a good thing. In
    2003, it's severely restricting innovation not just in race bikes but by
    implication in road bikes as well. But then racing is not really about
    technology now is it. It's about entertainment.

    Take a look at something like the Suzuki G-Strider
    http://www.cyberscooter.it/cx/spec/motorsh_tokyo03/suzuki.htm
    There are half a dozen reasons why this and anything vaguely like it
    would be illegal in any racing formula world wide. Even if you removed
    the entire fairing, the back rest would be illegal. Is that right?
     
    Julian Bond, Oct 31, 2003
    #6
  7. You probably know racing better than I, but I was under the impression
    that tire design and construction has made huge leaps, and is
    responsible for most of the recent lap time gains. Recall that when the
    250cc bikes started equalling 500cc lap times (leading to the Aprilia
    400 and other experiments) it was because they were carrying as much or
    more corner speed than the big bikes. By comparison, the substantial
    power advantage of the 500s amounted to very little with respect to lap
    times. (Of course, there is a big difference in being able to lap at the
    same time as another bike and being able to pass the other bike).
    It's a thought. Compared to bikes of yore, the contact patches are huge
    these days, and allow much greater cornering speeds. One thing that
    really changed the composition of 125 and 250 racing was when racers
    (pioneered by Kenny Roberts?) started mounting wider tires. The previous
    dogma was that you used light, narrow wheels to maximize top speeds.
    Roberts went to fat rubber that maximized cornering speed.

    I think dirt-tracker style has a lot to do with responding to prevailing
    traction and equipment: the tires and chassis right now respond well to
    being drifted flat-track style.

    That said, bikes are reliant on mechanical grip, and I think it will be
    hard for them to generate significant aerodynamic downforce in
    cornering. At the very least, the test runs should be scary.
     
    Ryan Cousineau, Nov 2, 2003
    #7
  8. I recently read an interview with Nicky somewhere on line, (wish I had
    saved a link to it) where he said that it took him a while to realize
    how much faster it was to get the bike straightened up so that he
    could blast out of the turns. This is in comparison to his superbike.
     
    Bruce Richmond, Nov 2, 2003
    #8
  9. Brafield

    Will Hartung Guest

    Ok, here's a puzzler for y'all then.

    How would F1 compare to GP if aerodynamics were not a factor. If the down
    force were eliminated, would they still be as dramatically faster as they
    are today?

    I'd think yes, solely because I think they can get more traction and contact
    patch than a bike can, but it's interesting to consider how much of an
    advanatage the aerodynamics bring to the table.

    Regards,

    Will Hartung
    ()
     
    Will Hartung, Nov 3, 2003
    #9
  10. F1 - aero = go-karts. On most tracks, I believe the fastest karts can
    lap faster than motorcycles. When it comes to lap times, cornering speed
    tends to overcome straight-line speeds.
    I would agree, but the aerodynamic advantage is massive.
     
    Ryan Cousineau, Nov 4, 2003
    #10
  11. Brafield

    * PHIL *` Guest

    I don't think the car without wings would stand a chance, because of at
    least 2 reasons ;
    1. Without the downforce corner-speeds would have to be a lot slower and
    they would have to brake a lot earlier,
    2. Acceleration would also be less impressive, no extra downforce on the
    rear wheels will leave them spinning.

    My guess is that any decend racing-bike would be able to beat that.
     
    * PHIL *`, Nov 4, 2003
    #11
  12. Brafield

    Dan Carter Guest

    Absent downforce, power-to-weight ratio would be a big factor. My
    wild-ass guesses:

    MotoGP: 220hp / 450lb (bike + fuel + rider) = 0.49lb/hp
    F1: 900hp / 1500lb (car + fuel + driver) = 0.60lb/hp

    But there's more. Without downforce, F1 cars would look much different.
    To minimize drag, cars would resemble the cigar-shaped machines of the
    pre-wing 1960s. Small frontal area and low cd, along with gobs of
    horsepower, would make them much faster at the end of the straight than
    a bike.

    F1, but a comfortable margin.
     
    Dan Carter, Nov 4, 2003
    #12
  13. I like the way you think ;-) But why limit the aero attachments to
    the rider's butt? (That's a rhetorical question BTW. Let's not get
    kinky.) The rider could probably better control panels attached to
    his/her/its arms and legs. WOW, get me my Bat suit :)
     
    Bruce Richmond, Nov 5, 2003
    #13
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