I’ve always wondered why Indy-car drivers do that weaving around stuff on the pace laps as well. A few years back a serious accident was caused by that action - so it ain’t all that safe to do in the first place.
Also - think about what happens later in the race. Pit stops. The driver comes in, 4 new tires, right back on the track, full speed ahead. No weaving, no tire heating, just plain old racing. Why do they not need that same weaving and heating action then?
-bs-
Here’s the link: Do race car drivers weave around the track to heat up their tires?
Please, folks, if you’re starting a new topic, please provide the link to the Mailbag Answer so that others will know what the heck you’re talkin’ about. Thanks.
Oops, sorry, I’m new on this message board. I’ll do that next time. Thanks for the assist (with the link back to the original message).
The announcers on NASCAR races also claim that the weaving back and forth on restarts also serve the purpose of cleaning debris of the tires. When the tires get hot, they get sticky and crud tends to stick to them. By weaving back and forth, they are scraping that crud off. So say Ned Jarret and Benny Parsons.
As a short track racer I can confirm the we weave to not only warm up the tires and make them stick better but also to get the crud off them. The get so sticky that driving through the pits will pick up all kinds of interesting things on them. And after a pit stop -if green you just do not have the time to scrub them much- you will see the Nascar guys smoke the rear ones on exit from the pits - if yellow you would do it just before the green falls. - and the “solvent” that the drag cars use is just water - used to be bleach till they figured out vaporized clorine was not a great thing to breath
fyi- Formula 1 slicks are no longer “slick”,they are treaded (somewhat)
Well, I for one am waiting for the wisdom of the Dopers in answering this part of the question.
The best way to heat tires is to run them at full speed, which is what they do as soon as they are out on the track. As for cleaning, I’m sure they would prefer to scrub them, but the chance is not there so they do without. But when they are running parade laps, the opportunity is there so they take it. Not much mystery there.
Re your earlier correspondent, F1 drivers do not weave their cars on the parade lap to abrade the surface of their tires. It is common practice to use scrubbed tires instead of new ones - that is tires that have already been used for a few laps in qualifying or practice, thereby breaking them in.
It is more likely that they weave to generate heat, although the effect is allegedly negligible. They hope that by adding heat, they will start to soften the rubber compound of the tire to increase adhesion. In addition, heating will increase the pressure of the tire by warming the air it contains. This will also improve grip. It was thought that lack of pressure in the tires was a contributory factor in the fatal crash of Ayrton Senna at San Marino in 1994, as he had just spent a number of laps trailing the safety car.
When donning new tires in a pit-stop, the pit crews will have warmed the tires to around 80deg in heated blankets before putting them on the car. Hence, they don’t need to do this weaving manoeuvre after a pit-stop.
You’d have to assume, that by speeding up quickly, the tires heat up fastest just based on friction. So in essence, if you are trying to warm them up, go fast 
Also, by weaving back and forth, you work the bugs out of the system so to speak. Like he said you pick up all sorts of crap on the tires, and it’s a good way to clean them off, but also to make sure that your car isn’t having problems, and that the alignmnet is still working alright. Hate to have one of those things not work going around a turn at 200 mph.
-Rico!
Go back and look at the first part of the original answer; the weaving is also to check the handling on the car. By the time the car is far enough into the race to make pit stops, suspension and wing adjustments are pretty much a done deal and all tweaking needed has been taken care of.
And in the process of leaving the pits, where the car quickly gets up to speed to enter the course, the acceleration down the pit road scrubs off anything that might be on the tires. By the time the car enters the course, it’s good to go.
The only time you’ll see that kind of weaving again is under a yellow (caution) flag situation; depending on how slow the pace car is rolling around the track, the cars may be weaving a little to keep the tires warm at the slower speed. Caution flags are often caused by incidents on the track and tires have an unfortunate tendency to pick up any debris scattered around; scrubbing the tires is sometimes indicated in that sort of situation.
BTW, thanks to all of you that have filled in some of the gaps in my knowledge; I’ve never personally attended a F1 event, for example. I grew up in sports car racing, but what I don’t know about all the things in it is a lot.
your humble TubaDiva
According to the “Days of Thunder” simulator ride at Paramount’s Great America amusement park (in Santa Clara, CA), besides being treadless, the racing tires are coated with a special compound that gets sticky when it’s hot. Is this “special compound” nothing more than non-vulcanized rubber, or what?
I recall seeing a piece on the Indy 500 years ago about how pit crews used ‘tire heaters’ to warm up the tires during the race. It looked like a big warming pad wrapped around the tire.
A quick search came up with nothing on the net, but I didn’t look that long or really know where to look. The closest I got was a page devoted to ‘Hydrogen filled, glow in the dark, tire pressure gauge’.
I distinctly remeber this, but I could be wrong.
Check out this interesting discussion I cam up with on a quick search.
http://www.seventhgear.com/edartic009.htm
About 1/3 of the way through, he talks about tire “marbles” and warmer technology. Interestingly, It doesn’t appear that CART uses them.
However, I also distinctly remember seeing these at the Indy 500, although I couldn’t find reference to them in a quick look at their website.
I was able to find some sites under searches for “tire warmer” and Tyre warmer", but they only showed pictures of uses on motorcycle racing.