Re: Wandering, Negative Steering Roll Radius?

[Phil Rose <pjrose@servtech.com>]

>Date: Thu, 04 Feb 1999 16:47:04 -0600
>From: Luis Marques <marques@ti.com>
>Subject: Re: Wandering, Negative Steering Roll Radius?
>
>  "NSRR places each front wheels pivot point outside the center of the
>   tires axis. This has the effect of making the front wheels want to
>   return to center-to turn in the direction opposite that of the
>   pivoting force-even under conditions when one front tire has far
>   better traction than the other. When this happens on a conventional
>   automobile, as when the driver must brake hard in a corner, has a
>   blow-out, or has one front wheel drop off the road, the front tire
>   that retains traction has greater stopping power."
>

>
>I would think that the same "negative radius" feature is designed on the
>caster plane.  Having the front wheels centered behind the pivot point
>will probably make the car's own weight force them to point straight
>ahead.  Now that I think about it, this should be more effective in
>curing the wandering of wider tires than having more offset on the
>wheels.  It is well know that if you increase the caster, you improve
>high-speed stability (at the expense of increased steering effort), just
>like the fork offset in bicycles.  For a car with McPherson struts, this
>could be achieved by moving the strut bearings back a little.  Not easy
>to do on a 4kq, but perhaps easier to do on a 5000/200 etc.
>
>Luis Marques

Yeh! That's the notion I had (um, pretty much, more-or-less, approximately,
give or take) when making my comparison between NSRR to bicycle steering
geometry. I didn't express it very well--in fact it's obvious that I didn't
get it expressed at all :-) Thanks, Luis.


Phil Rose				Rochester, NY
'91 200q				mailto:pjrose@servtech.com
'89 100