wide wheels with rather narrow tires

[Arryn Milne]

At 09:52 PM 1/16/01 -0700, auditude at neta.com wrote:
>On 16 Jan 2001, at 18:47, Stephen Bigelow wrote:
> >
> > > What is tramlining? And a narrow tire is better?
> >
> > Tracking on cracks or ridges in the road.
> >
> > > How do you say? Doesnt
> > > it make sense that the stiffest widest tire possible will give the most
> > > dry traction? More rubber contact to the ground, and least amount of
> > > flex?
> >
> > Least sidewall flex, yes. More rubber on the road, no.
> >
> > Contact patch size is a function of wheel loading and tire pressure.
> > Contact patch shape is a funtion of wheel width, tire width, tire pressure
> > and wheel loading.
>
>To add my 2 cents, if you increase contact surface, then the
>pounds per square inch of that surface is decreased.  There is a
>point beyond which the weight of the car is so spread out over all
>that tire surface that the tire isn't "pressed down" into the pavement
>hard enough to get any traction.
>
>That's clumsy way to try to explain it, but that's what came out.
>
>Later,
>
>Ken

I'm no engineer, but I thought that as long as the weight was the same, and 
the tires were the same diameter, that going to a wider tire simply changed 
the shape of the contact patch more than anything else, ie: a narrow tire 
will have a more longitudinal patch which would be better for acceleration, 
while wider tires with a more lateral contact patch would be better for 
cornering.

The above was a generality, and I assume there are tradeoffs (otherwise 
tires would tend toward one extreme or the other).  Look at drag tires, 
narrow relative to height, and can-am cars, wide relative to height.

I've been working on that theory, and considering quattro provides for good 
acceleration (lessening the need for a longer patch), wider is better :-)

Arryn