[simpits-tech] Bike Sims; a physics lesson (was: Re: Air & Space Smithsonian....)

[Sean Galbraith]

At 05:10 AM 5/22/03 -0500, you wrote:
>Sean Galbraith wrote:
> >
> > To understand what happens you need to know a little about gyroscopic
> > precesion <sp?>.
>
>I knew about precesion, but there are other theories that sound good, too.
>One is that you turn the bars right and the bike starts turning right, but
>inertia leans the bike to the left. At that point the tires being on the
>side overcomes the angle of the front wheel so the bike turns left.

Ahh the trip_over_the_curb theory... I believe in that one too :)  Best 
argument I ever saw/heard was between a couple of instructors on which 
theory was more technically correct.....

> > On my GSXR-400 track bike
>
>Bastard ;) I want a ZXR400R myself (I think that's the right string of
>characters, anyway) for a trackbike.

Yeah well, in a fit of absolute stupidity I sold the thing... wish I hadn't 
now :(


>Ever hear of the No BS bike? It's a ZX6R with some bars and a throttle
>mounted rigidly to the fairing stay. It'll just barely turn by leaning the
>bike, but countersteering on the normal clipons is the usual 6R lightning
>fast.

California Superbike School perhaps... I think they had something like 
that.... would be frightening to ride!

> > to fall off the thing :) A bit like the whole motion cueing vs actual
> > motion discussion for full motion sims....
>
>Yes, but it does have to move at least, say, 10° since you can feel the bike
>leaning when you start a turn. It doesn't have to go far, though.

Yes, agree with that :)  The heave would be more important that the actual 
lean angle, which your brain would interpret from the visual cues.

> > lean angle in software, and a much smaller motion of the "bike".  The
> > coolest part was that they had the road on an angle on either side of
> > the
> > bike so that the riders could get their knees down :)
>
>Hmm... a couple of garage sale treadmills? ;)

Bingo!

> > - Biggest problem I can see is creating the physical relationship
> > between
> > counter steering and lean angle.....
>
>Pneumatics or really, really fast electric rams.

Scary fast rams would be good.... I don't know how you would do it, but 
then I'm just an ideas guy <vbg>

>if possible). That'll do a LOT to trick the brain. A tactile transducer
>under the seat to simulate engine vibration would be needed, too. If played
>in the dark with the sound turned up it would probably be enough to make
>non-bikers sick.

If you were simulating the VTR I'd suggest a honking big transducer just in 
from of the seat... man does that thing vibe when it's making power!

>people fell backwards trying to compensate for it. A couple of people even
>walked flat into the wall thinking it was many feet farther away. After the
>room gave our advisor a migraine that sent her home for the day the
>principal made us take the tape off even though he thought it was a really
>Cool experiment.

Tormenting teachers AND riding fast bikes... now we're talking :)

>I'm going to my first trackday in August if everything works out right. I
>actually bought my 7R from an instructor and have pics of it on the track.

The track is *the* best place to learn the intricacies of fast bike 
physics.... honest that *is* what I was doing all those years ;-)

>Colin Edwards lives about 15 minutes from here. I run into him every once in
>a while around town.

So we have the former Honda Super's squad wrapped up here...

> > Oh, and when you get it finished I'll bring the beers, my leathers
> > and Arai ;-)
>
>And if you ask real nice I might let you ride one of the things in my
>signature ;)

Deal.

Sean.