I would guess it may have to do with design trade-offs making
the sidewall conform to a flat contact patch in a short distance.
Fatigue jumps to mind.

The ones I have seen are.  The rotation adds a bit to the effective
mass, but nowhere as dramatic as some claim.

That is a real issue to me.  While your wheel is off the ground,
its traction performance is quite poor.  It also reduces driving
comfort.

Leon

I'd expect the sidewall to be much thicker (and thus heavier), to reduce
the odds of bending wheels in potholes. Folks with 35- and 40-series
tires report plenty of bent rims anyway, but I guess it could be even
worse.

They also must be stiff enough not to roll under at all. I recently
heard of a kid with some cheap, flimsy bling tire rolling it under in an
autocross and actually catching the rim on the pavement. Cars have
flipped from that!

In article <RwHmd.198u.111@twister.nyroc.rr.com> dm@nospam.com (Dave) wrote:

Cynics regard everybody as equally corrupt. Idealists regard everybody
as equally corrupt, except themselves.

Say, do you have any psychological problems?

A poor beauty finds more lovers than husbands.

Basic systems for a gravity distortion system allow time travel. They
are:

1. Magnetic housing units for dual microsignularities.
2. Electron injection manifold to alter mass and gravity of
microsingularities.
3. Cooling and x-ray venting system
4. Gravity sensors (VGL system)
5. Main clocks (4 cesium units)
6. Main computer units (3)

I am sure you are not expert enough nor do you take cars to their
limit.

The civil war in the United States will start in 2004. I would
describe it as having a Waco type event every month that steadily
gets worse. The conflict will consume everyone in the US by 2012 and
end in 2015 with a very short WWIII.

--
Lady Chatterly

"Lady Chatterly bitch slapped you and you just can't deal with it. I
bet you pull typical Pangborn and go run and hide from her now." --
Aratzio

Few years back, just around the time I bought my 2000 NB, there was a story
in Road&Track or Car&Driver (can't remember which) where they lined up a
bunch of sports cars and a couple of pro drivers on a road race course and
did a stopwatch comparo.  Idea was to figure out which car was the fastest,
mixing classes and types of automobiles.  Among the contenders were Miata
(of course), Corvette, M3, 911, Elise, S2000, 360 Modena, Viper, etc.  Maybe
there were 10 cars?  The Elise was supposed to be the "ringer" but it didn't
come out on top.  Idea was to allow all of the drivers drive all of the
cars, average their track times and pick the winner.  So it wasn't a
raw-numbers thing as far as lateral grip or slalom time, but had to do with
how easy the car is to drive.

Anyway, Miata finished near the top but not absolutely on top, but did
amazingly well considering it had 1/4 the power and 1/8 the pricetag of some
of the cars in the lineup.

Some of the comments about the Miata from the drivers showed the real point.
 They said while the Miata had lower limits for absolute cornering than,
say, a Viper, they said it was possible to drive the Miata beyond the
cornering limits...  drifting every corner, walking it around corners, etc.
 But that going over the limit in a Viper was such a disaster that you had
to drive under the limits all the time.  So the measured limits did not
correlate to the performance.  Even with a major horsepower and numbers
handicap, Miata performed in the top of the pack because it could be driven
faster around the track, regardless of the limits.

So the ability to drive over the limit, recover, control the car when it's
in a slide, predict the behavior of the car, stability of the car over the
limits, etc., all affects how the car "handles" and also how fast you can
drive it.

For example, I had a VW Jetta GLI 16V with full-blown race suspension (and
street tires) that drove on the street like a go-cart.  It was crisp,
nimble, lightweight, would corner VERY fast, had insanely high cornering
limits, etc.  Really, below the limit, in an entirely different league from
a Miata.  But woe to you if you imbalanced the car in a corner.  Lift the
throttle just a LITTLE BIT inside a corner and you were going to very
rapidly swap ends.  Brake hard on the way into a corner was a sure fire way
into a spin.  You had to throttle through corners and know exactly how and
when to brake, steer, etc.  It took a much higher amount of skill, and more
margin, to drive the car.  After the rod bearing went out on that car, I
bought my 2000 PEP Miata and even with the factory 14" wheels/tires it would
go through any corner faster than my racer-boy 16V.  The reason is because I
could drift controllably around a corner in the Miata, feel it slowly coming
around and bring it in, brake inside a corner, hey, the car's forgiving.
Under the limit, yeah the 16V felt a lot more like a go-cart.  However, in
the end, I guarantee my bone-stock Miata is a faster car in the hands of
most drivers.  Someone specializing in driving front-drive VW's with
enormous amount of roll stiffness in the rear could probably make the 16V go
faster, but that would take really special skill.  Miatas are fun and fast
every day, for any driver.

This is the same thing that made Datsun 240Z's such popular and fun cars for
most people, even though there were certainly faster and more powerful cars
out there, the Z cars dominated on the race track.  Balance, poise, ease of
recovery, and predictability are all very important in a sports car.  In
fact, I'd say these factors are what separate a "true" sports car from a car
that's just a sporty-styled "fast" car.