[Supras] 18" or 19"

[Jeff Mohler]

Simple, more mass farther from the hub, creating tons more rotational
momentum for the brakes to now try to stop as WELL as stopping the moving
mass of the car.

Thats why for performance we want the lightest wheels & tires we can find,
and also..the smallest diameter.

Wider diameters have a higher %age of rotational mass farther from the hub
as compared to a smaller diameter wheel/tire combination.

That 19" will weight more as well, resulting in a slower performing
suspension, which will force the tire to accept more road bumps and
holes..than the suspension itself, because it will accelerate up & down
slower than a lighter combination...and thats why you see more split
sidewals and bent wheels on larger sizes compared to smaller ones.  Of
course, a strong-ass 19" wheel would also weigh about 35lbs..if not more,
which makes things even worse.  The tire will weigh 25-30 as well.

Rotational mass hurts WAY WAY more than dead weight in the chassis.

Also, a wider diameter wheel/tire combination with a higher %age of weight
towards the outside of the total diameter will act as a much more powerful
gyroscope than a smaller tire/wheel combination, which will affect high
speed cornering and transitional handling.

Four 50lb gyroscopes at 50mph is a powerful tool that either works for you,
or against you.


Basically, theres no gain to a larger wheel over a narrower one, except for
brake fitment.

If I could run 13x9 wheels and STILL have enough braking to handle the
heat/friction requirements that I could USE with a 275 wide tire on the
racetrack..I could.

But the penalty is I need more brake to use all of a 275 tire than a puny
1983 rx7 rotor and caliper can deliver, so the tradeoff is I would need a
larger heavier and momentum-hungry wheel to fit it.





On 4/9/07, C Fernandez <fernande at internet1.net> wrote:
>
> Jeff,
>
> How would bigger diameter rims put more stress on the brakes?  Larger
> diameter tires, yes, but rims?
>
> Chad Fernandez
> Michigan, USA
>
> Jeff Mohler wrote:
> > Bigger wheels will strain your suspension and braking system a lot more
> as
> > well.
>
> _______________________________________________
> Supras mailing list
> Supras at supras.com
> http://supras.com/mailman/listinfo/supras_supras.com
>