<VV> Wheels and Tires Question

[Kirby Smith]

I think it depends on the tire design.  The late '60s reverse-moulded, 
bias-ply, "cantilever" race tires (I hadn't seen that name association 
before seeing it on this forum, but it is apt) such as the Goodyear 
Bluestreak 4.75/8.50-13 tires I still have (as mementoes) have 7-inches 
of tread and were certainly designed for wheel widths smaller than 
either the tread or section widths.  Section height to section width 
ratio is around 50%.  So I guess today they would be 250/50-13s.

The stock tire on my '95 S6 is sized at 225/50-16 fitted to an 8-inch 
wide wheel.  The Bridgestone SO-2s I use have 8.5 inches of tread. 
These are radial tires based on a more modern race tire design, and do 
not have as sharp a tread edge as the reverse moulded tires of the 
ancient past.

They do have very large curved grooves to throw the water to the side of 
the tire.  It takes a lot of standing water to force them into 
hydroplaning, a rather uneventful phenomenum anyway in a quattro.  The 
lesson is to make sure that any wide tire used where it rains has a 
groove design suitable for the water depth and speed anticipated.

kirby


Bryan Blackwell wrote:
> I've read that as well - in fact, it's in How to Hot Rod Corvair Engines 
> to use wheels as wide as the section of the tires.
> 
> --Bryan
> 
> On Sep 15, 2005, at 3:42 PM, Bruce Schug wrote:
> 
>>> And it depends on what you want: tall or wide. Personally I find 
>>> anything lower than a 60 profile to be, well, you can tell if the 
>>> cigarette butt you just ran over was plain or filtered. They also 
>>> demand wide rims (for street my rule of thumb is a wheel as wide as 
>>> the tread, racing it should be as wide as the section).
>>
>>
>> I thought the rule-of-thumb for racing is that wheel width equals 
>> tread width. You apparently disagree.
>