[Author Index]
[Date Index]
[Thread Index]
[Date Prev][Date Next][Thread Prev][Thread Next]
Re: heavy crosswinds
- Subject: Re: heavy crosswinds
- From: greg clark <boris@xxxxxxxxxxxxxx>
- Date: Wed, 03 May 2000 08:24:09 +1000
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"
>
> * * * * * * * * * * * * * * * * * * *
> The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
> http://www.TriumphNet.com/st/lilley for more info
> http://www.TriumphNet.com/st for ST, RS and Mailing List info
* * * * * * * * * * * * * * * * * * *
The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
http://www.TriumphNet.com/st/lilley for more info
http://www.TriumphNet.com/st for ST, RS and Mailing List info
=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=