rbeckham

I never heard of this before, but my latest set of new R Compound Tires (Nitto Nt-1s) came with a sticker warning against driving after exposing the tires to sub-freezing temps. It appears that catastrophic failure may follow because of structural weaknesses caused by freezing. I'll be at Watkins Glen in late October, where this condition may indeed happen overnight.

Does anyone have an informed opinion about whether this is something one really needs to worry about? If so, is there a solution such as heating them up in the morning with a blow dryer before driving on them?

rasrboy

From my experience in the tire industry, you should be ok as long as you don't bounce/slam the tires around when it's cold. This is where they can crack like peanut brittle.

We store our race tires in a warehouse in the winter at a controlled temp but we are still very carefull not to DROP them or throw them around in any way. Just get a few laps in them and bring the temps up as best you can per weather conditions. Stay OFF the speed bumps and on track & look at them after every session for any problems.

The side walls tend to split first as this is where most of the load is. Look for any splits/cracks, but other wise you should be fine.

Just my .02 cents worth.

Aaron
Kumho Tire (Motorsports Division)

rbeckham

Well, I don't intend either to bounce or slam them. My intention is to drive on them at pretty high speeds and lateral g's, and so would prefer they not act like peanut brittle in the process.

Seriously - I am trying to figure out whether this is a real issue or not. If you get up early in the morning and it is 30 degrees outside and you jump in the car and drive to the track, how likely is it that your tires will disintegrate under you at high speed? Inquiring minds really do want to know.

0Randy@DRM

Coming from the great white north.
Race shops sell very spendy tire warmers.
If you have a enclosed trailer, use a heater of some sort. If you are on a open trailer, use blanks. The frost is moist and will soak in worse, so install blankets after the last run, they will be warm still in the am.

Then do everything Aaron said and you should be ok. The reason I said should be. I have seen many of tire comna-A-part from all brands.

Randy

Iceracing has taught me one thing, racing in the cold sucks but fun.

rasrboy

Good call on the blankets Randy! The SCCA Solo boys had those on at Topeka last week in the cool mornings.

autoxer6

I have designed a lot of rubber seals for valves. I attended several rubber design engineering seminars around that time with instructors from the tire industry.

Rubber compounds are designed to work at a specific temperature range. When the temperature is to low, the rubber does become hard and to some extent, brittle. Rubber that is exposed to cold is rarely damaged by the freezing. For auto tires, I couldn't understand how they could sell a tire that is damaged just by exposure to cold weather. Racing on 30 degree tires is a different story. The repeated flexing of the sidewall under heavy load can cause cracks or delamination of the tire. The rubber simply isn't soft enough to flex.

Basically, I would take it easy for a couple of laps the first time out in the morning. Once the tire is warm, it should be fine.

Tire warmers would be nice. Or you could just leave them in your car with the heater on for a little while. That's what I would do!

Chris