THSCC Forums

This is not the place to ask "are my tires illegal?".

If you've measured your tire and found it to be illegal, post it here, along with the measurement. I have no plans on developing a "legal tires" list.

Reminder: 0.22" or more is illegal.


I was looking at the tires on my Geo last night and thought they looked illegal, so I measured them this morning in the snow.

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The List
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0.25 Kumho 770

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Lina Racing: As Seen On Radio

Kumho MX's 0.28" (from memory)

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In need of car.

Ok I have to chime in here about the whole tire issue. This is not a sanctioned event by anyone, except us. When the rules for a type of event that occurs a couple of times a year, hopefully more soon , disallows tires that are normal street tires it seems a bit dumb.

The 770's are some basic all weather kuhmos that are proabably very similar in tread design and spacing to most all weather tires that most people have on either their daily drivers or beaters. And these are the cars people are going to bring out, to have FUN. To disallow or ban these tires because of the .22" rule seems a little unfair to people. The rule is very important in competative events to prevent "cheater" tires, uh-oh I mentioned that phrase. But at our events, I mean come on.

Sorry, I'm off the soapbox now.

Mods, you might want to split this thread as this is sort of OT, but here goes:

First; Anders, Carl, and the other rally gurus -- don't take anything I say below personally. You all are experts, I'm just an autocrosser with an AWD car.

I'm with Adam here in that the reason for our .22 rule is getting ignored in strict adherence to it.

As I understand, the _entire_ point of the .22 tread groove rule is to prevent people running tires such as true rally tires and/or M&S tires that will destroy the quite fragile surface of Kevin's field and keep us from making many runs in a day.

The .22 thing was taken verbatim from some other club that has used it successfully to split off "rally tire" classes from "street tire" classes. We're using it for something different, in that we're using the .22 rule to allow/disallow _participation_. I don't think _anyone_ would feel that the Kumho MX or Kumho 770 or Conti SportContact are destructive to the site yet they are disallowed because they don't fit within the .22 rule.

Why don't we try something slightly different that should keep the site intact yet allow people with wide tread tires to compete. I'd propose something like:

All tires allowed, except:
--Non-DOT rated
--Light truck M&S
--Rally tires
--Snow tires
--Anything the event chair disallows as too aggressive (we've got this line already, right?)

Just my scattered thoughts, take 'em for what it's worth.
--Kevin H.

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2003 WRX (again!)

Just to provide some enlightenment here. I think the whole .22" max tread gap isn't really about disallowing tires that have a performance advantage. The rule is aimed more at maintaining the quality of the track throughout the entire event. I guess the theory is that the larger the gap in the treads the more dirt the tire will rip up as it goes around the course.

Since we had 30 cars entered at the last event X 6 runs each your looking at 180 passes over the same patch of dirt. If all those cars showed up on really aggresively treaded tires we would have probably dug so far down into the sand that the course would have ended up looking like a bobsled run.

So it always comes down to this, if you are going to make a rule then you have to draw a line somewhere and in case the club picked .22". Remember that this was just the initial ruling to try and prevent course damage, I'm sure this series evolves the rules will evolve as well. If we keep getting good feedback hopefully we will eventually develope a rule set that almost everyone can agree on.

I do see that it is a problem that tires like the Kumho MX's are illegal under our current rule. I mean you can look at the tire and tell that it wasn't designed for dirt at all.

I'm not sure how to fix this rule. Maybe can say .22" or any tire with approval of the Rallycross cheif of tech? Or we could say .22" or any tire on this list of approved tires.? That way we could put tires with large blocks and gaps like the MX on that approved list.

Shawn

ps. Just thinking out load here not as far as the proposed rules, not setting new policy.

I agree completely and thought my post above made that point. Guess I need to work on those written communications skills...

My other point from above is that the .22 thing is arbitrary and was apparently used for another purpose by the club that created the rule. That's why I suggested an alternate way to disallow tires that might tear up the site without disallowing common apparently non-destructive tires like the Kumho MX or Simon's Continentals.

--Kevin H.

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2003 WRX (again!)

Nope actually you need to work on your timing. Look at the post times, I was typing mine while your post popped up. I didn't intend to make the same point as you. I just type too slow.

Shawn

After my Continental's were flagged as too agressive at the last (first) rallycross I found that someone else had run on them but they had been marked with a legal tread gap measurement. I asked Carl for a ruling on my tires and he said they were fine. I think it was a difference in the way the examiners tested the tread. I watched them very closely and saw them measuing the diagonal tread about 1/3 of the way in from the edge. Looking at Anders' picture I feel sure they were measuring the equivalent of the outer, angled red marks. Carl measured where the yellow marks appear and they were legal.

They are not mud/snow tires but simply high-performance all-seasons. So I'm planning on running on them at Four Oaks.

Thoughts?

Simon

You're all correct. I did pick the number 0.22" because another club uses it to distinguish "street" from "mod", but I happen to like it when rules are common between clubs whose events our members are likely to run.

As anyone who was at the last event knows, this site is prone to getting torn up. However, there is no one magic number above which surface wear becomes excessive, as far as I know. It is a simple case of the less aggressive tires we have out there, the longer the surface is likely to last, and the less abusive (and more fun) the courses will be. And, as Shawn mentioned, we have to draw the line somewhere. So considering all of the above, I still like the 0.22" tread-gap spec.

Yes, it's a fledgling program in our club, and there's no real reason to be too "serious" about it right now. But I think a good set of rules makes for a good foundation, and I'd like to have that. Consequently, any of the rules is open to revision. It really does bum me out that some common street-tire choices don't meet the current rule, and maybe we may want to play with that number a bit to find the right compromise. But, of the cars that showed up last time, 90-95% complied with no problem. We've got to draw the line somewhere, and 90-95% initial compliance makes we think we're not way off base.

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Carl Fisher

Be Cool to the Pizza Dude:
http://www.npr.org/templates/story/stor ... Id=4651531

Carl is right, of course. I think I need to drink less caffeine...

With the informality of our program the .22 rule combined with a little flexibility by the event chair (which is what happened at the first event) does work just fine. I'd just hate to have someone skip an event because they have BFG KD's or A032R's and they didn't think to ask the chair for an exception.

--Kevin H.

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2003 WRX (again!)

For note i was running the same tire as simon. The reading for the Continental's was .19.

Another data point: Measured the RE-750's today, and they are _close_. The widest tread block on the outer edge is .215 or so. The narrowest is about .170. I guess Bridgestone varies the width to reduce noise.

--Kevin H.

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2003 WRX (again!)