Last week I kiddingly posted this shot of my tires on the trailer, but now I'm told that these are actually dangerous, even for practice. Something about the compound being irreversibly damaged. Really? (And please excuse the inversion, I'm on a remote)

 

What kind of tires?

 

Many R-compound tires will develop cracks if frozen. Once that happens, they're pretty much toast. Here's an advisory from Toyo, as an example.

 

Treat them gently until they thaw and look for cracks before using.

 

Pirelli clearly states on the tire stickers (on its slicks) that they should never be stored in temperatures below 5 degrees Celcius. I suppose they didn't put that on there to fill the sticker

 

Is it true that it is worse for a tire to freeze if it has never been heat cycled?

 

Does Hoosier transport its tires from the factory in Indiana via heated trailer? If not, presumably tires would freeze all the time.

 

Seems like it would also matter if the tires are aired up (at all), and even worst if under load. If they're bled out and just sitting, I'd be willing to use 'em again for practice/testing, if you absolutely leave them alone till they're warmer. That said, they also shouldn't be sitting out in the sun going through those heat cycles. So these are probably junk, yeah.

If you leave 'em empty in an unheated garage out of the snow and sun and weather, away from electric motors, then useable (but shagged-out)...

 

I stored my 964 cup on some old Pirelli's one winter long ago...It got down to -5ish...Sidewalls were cracked and crumbling in the spring...That "experiment" convinced me that any slicks or R-compounds need to be stored indoors during the winter months.

 

I've heard of a scrub slick cracking and suddenly going flat from a drop off a tire rack on a cold morning at Mosport, but I didn't see it happen.

I would be curious to know what freezing can do to R-comps, if someone has any data.

 

My everyday car has Pirelli P zeros . I have been driving them in our 0-15degrees that we are having . No issues other then really slick till about 10 min of driving

 

My Hoosiers from last year spent the winter in freezing temps. The newest set had maybe 3 heat cycles and they were useless at Sebring last month. I'll never buy tires late in the season again without storing them in the basement over the winter.

 

Hoosier will not ship me tires when the temperature is below freezing. I routinely have to wait for shipments during the winter.

 

from the Hoosier website....

FREEZE WARNING

Freeze Crack Advisory: This advisory addresses proper storage and use of Hoosier tires in cold conditions. Hoosier Tires, especially asphalt and hard compound tires, may experience Rubber Cracking if the tires are transported, crushed, flexed or stressed when frozen. The following guidelines are provided to avoid this problem.
1. Always store Hoosier Racing Tires indoors at temperatures above 32° F.
2. If tires have been subject to 32° F or less, allow them to warm to room temperature (about 70° F)
for a minimum of 24 hrs before tire is mounted, transported or flexed.
3. Always use spare tires not intended for future competition to store vehicles for prolonged periods
of time or winter transport.
4. If below freezing temperatures are expected, please consider shipping tires once more favorable conditions exist.
Do not use tires that have evidence of Freeze Crack Damage.

 

I used a set of 20+ cycle RRs that had been outside until they left for FL and they were faster then the stickers I put on for the weekend.