Re: heavy crosswinds

[greg clark <boris@xxxxxxxxxxxxxx>]

Jim
     Would that be in a X-wing or a A-wing.
      May the force be with you.
Greg Clark&y2kblue
Aust.
Jim Huber wrote:

> >  From: Eric Sheley <eric@xxxxxxxxxx>, on 05/01/2000 09:58:
> >  At 12:21 AM 5/1/00 -0700, don draper wrote:
> >  >  The amount of effort required to correct for a crosswind is DIRECTLY
> >  >proportional to the height of the CG above the roll center of the
> >  >bike.
> >
> >  Huh ? We weren't talking about the amount of effort required.
> >
> >  The original question was not why it was required to lean in, but rather
> >  why in addition to leaning into the force there was also a certain amount
> >  of force that was required, directly opposite to the lean angle (in this
> >  case in the direction of the wind).
> >
> >  Let me see if I can break it down a little simpler. I will forgo the vector
> >  mechanics discussions as I don't think that will make the scenario any
> >  clearer.
> >
> >  These are some broad generalizations:
> >
> >  1 - A bike travelling in a straight line will continue to do so unless some
> >  external force is applied (wind, input from the bars, throttle etc)
> >
> >  2 - A bike travelling at a lean angle will travel in the direction of that
> >  lean (again very basic - we are not concerned with cg here)
> >
> >  3 - If the lean angle is increased the radius of the turn will be decreased
> >
> >  Of course in addition to the angle, the radius can be changed by tire size,
> >  tire profile, wheelbase etc.... we are not concerned with these factors
> here.
> >
> >  So we now have our bike travelling in a straight line. We now add a force W
> >  (wind) from the right, perpendicular to the direction of travel (things get
> >  really fun when the angle is <> 90). So in order to compensate for a
> >  quickly shifting motorcycle the rider begins to "lean into" our force W.
> >
> >  Now - abruptly remove force W. What does the bike do ? It immediately
> >  begins to turn to the right. Now add the force W again. That same tendency
> >  to turn is still present - only now, force W is acting against it. However,
> >  if the combination of the lean angle and the profile of the tire at the
> >  contact point are such that a turn in the direction of travel is still
> >  being caused (even at a minute level), some force must be introduced into
> >  the equation to compensate (to cancel out this tendency to turn). In this
> >  case a constant pressure to the left would be required - which is why even
> >  though leaned to the right, Patti had to exert a constant pressure on her
> >  left bar to maintain straight travel.
> >
> >  There - clear as ...... mud ?
> >
> >  Respectively submitted
> >
> >  - Eric
>
>         Yep, clear 'nuff. And I agree with you, too. Pilots call it
> "cross-control". It's the same thing you do when landing a plane in a
> crosswind: bank into the wind but use the rudder to counteract the actual turn.
>
>         "Jedi Dawg"  Jim Huber
>         Spring, Texas, USA
>         '00 blue ST  "Rhiannon"
>
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