Should Spec Tires Marble?

[paul-collins]

I've posted this on another forum, but thought I'd ask the question here as well.

A question for those who were wondering about the yellow flag near the end of the Grand Am race at Phoenix.

I'm not suggesting that the tires in fact did not shed rubber at Phoenix, but since there's no performance improvement needed, shouldn't the tires be built with this in mind? I know that Bridgestone has worked with CART to reduce marbling because they are trying to maintain multiple clean lines through corners.

OTOH, perhaps it's just something that we (fans and racers) have to live with. I don't know anything about tire wear and construction.

Actually, now that I think of it, multiclass racing has this as a benefit - with all the overtaking, the cars are constantly sweeping the road clean.

So here are some follow-up questions:

What about ensuring that the marbles are of a maximum size, so that they're more like bb's and less like strips of rubber?

Is the lack of a need to clean up corners at Le Mans a function of fewer cars (per mile of track) over a long race? Or is it because of the multiple lines that have to be used and the aforementioned sweeping action by the passing cars?

Here's the breakdown of trips through corners:
Number of cars x Number of laps = trips through corner during a race.
(i.e. the sum of each car's laps at the end of the race for the whole field)

Phoenix 2003 = 2343 laps total
Le Mans 2002 = 11724 laps total. That's 5x the number of cars through a particular corner.

Do Le Mans workers duck out and sweep sections of track during the race?

Ayse/Fab, this probably belongs in the "Technical" forum, but I thought I'd start it here. Hope you don't mind.

[Fab]

I don't mind at all and it opens a new debate... the track is not clean during the race, if you ask. Marshalls try to clean the stones as they could, but very few. Not talking about rubber and carbon pieces on the track...

[Lee Janotta]

Well, sticky tires actually help in overtaking, giving drivers more margin of error. But the marbles do tend to negate that, by destroying any chance at traction off-line.

[gttouring]

as per original question and CART's qork- Spec tires should keep the marbling down to a minimum, there is no advantage of a super grip tire ripping to pieces in 10 laps when evryone is running the same tire, a good compromise is best a tire that rips well to keep lap times consistent and which will break apart less, if everyone is using "stone" tires to keep the marbles off the track then the laps times should be similar among similarly prepped cars, and keep the track free of debris. you are only in competition with your series adversaries not someone else, so it shouldn't matter.
So yes spec tires should keep marbling down.