Lets talk tire legality

SimonWright · **Posted:** Mon Dec 05, 2005 12:56 pm

PJ Aspesi wrote:

well i understand taller tires get through deeper ruts/mud.......<snip>

I think it's more that narrower tires get through deeper ruts/mud.

Simon

PJ Aspesi · **Posted:** Mon Dec 05, 2005 1:03 pm

oh yeah thx simon!

Carl Fisher · **Posted:** Mon Dec 05, 2005 1:17 pm

Well, as you might guess, it's a tradeoff. Taller sidewalls will deflect more and may be more prone to debeading, but lower-profile tires will also transmit more shock to the wheel. What you really want is stronger sidewalls, and some brands and models are going to be better than others in that regard. It certainly appears that whatever is on the Dirtmaster is not a good choice, for example. Driving style certainly plays a part in the stresses that the sidewalls get, but I can say that debeading has not really been a problem for me in the Neon, and I have my front tires inflated to only 38psi (disclaimer: I was not driving when we debeaded at BMW Farm, and before I debeaded a rally tire yesterday, several people had commented to me that the tire was low).

You can search this forum for links to the tires I've used, or you might want to look into light-truck tires (if you can find some suitable ones), as they usually have stronger sidewalls. BTW, special-purpose snowtires like Blizzaks and Nokians usually have paper-thin sidewalls, and I would not recommend them for rallycross use.

Hope this helps.

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

So I got the new Avons on the RS and out into the field for some testing yesterday. Very hard to get the car to slide; lateral grip seemed almost rally tire level. Tires barely spin at launch & very little wheelspin coming out of tight corners. Very stiff sidewall - felt about like Falken Azenis RT215.

Grip on the road is also very good, considering they're all-seasons; I had already figured this out with the FXT, but confirmed with the RS.

These are the same tires that were on the Forester XT when I rallycrossed it a few months back (it was pretty fast, in case you weren't there or weren't paying attention.

). Just in a different size.

Info: Avon Tech M550 All Season; size 205/55/16

WalterHouston · **Posted:** Tue Jan 17, 2006 6:10 pm

The old Maxima that I'm getting for $100.00 has two good mud and snow tires on the back. Since I want to run in the street tire class, will that be a problem? I'll buy some legal tires for the front.
Thanks.

BretLuter · **Posted:** Tue Jan 17, 2006 6:43 pm

WalterHouston wrote:

The old Maxima that I'm getting for $100.00 has two good mud and snow tires on the back. Since I want to run in the street tire class, will that be a problem? I'll buy some legal tires for the front.
Thanks.

My interpretation of the rules is that you'd have to run in Rally tire class with those unless they have very closely spaced tread blocks.

Have a look at the rules, I'm pretty sure it's spelled out there.

Bret.

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

I think the "mud and snow" thing is being misinterpreted by some people. A lot of "ultra high performance all season" tires have "M+S" on them, meaning they're mud and snow capable. My Avons do. What we're disallowing is REAL mud and snow tires - as in, mud tires that would go on a mudsling truck or snow tires that you'd put on only during winter when it has snowed (or if you're Anders, for Sandblast Rally

).

If it's an all-season tire, it would have to be a very strange all-season tire to be disallowed for street tire class.

Carl Fisher · **Posted:** Wed Jan 18, 2006 6:52 am

From the rallycross rules (http://thscc.com/rallycross/info/rallyx_rules.html):

Quote:

Street Tire: For the purposes of this class, a "street tire" is defined as a "summer use" or "all-season" tire from any manufacturer that does not have an knobby or overly aggressive tread pattern, as determined by the Rallycross VP or his designate. Specifically excluded are snow tires, rally tires, mud-terrain or all-terrain tires, and any tire with a knobby tread pattern.
The intent of this definition is to permit any "normal" street tire to be used in competition. However some tires will obviously push this limit, and the Rallycross VP reserves the right to make (or delegate) that determination on a case-by-case basis. Note: many OEM truck and SUV tires will be deemed too aggressive to meet this classification.

Hope that helps.

Ryan Holton · **Posted:** Wed Jan 18, 2006 8:31 am

An illegal tire is like porn. You know it when you see it but its hard to define exactly....

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