I wonder. Do you get the same results if you heat the tires in an oven or is the stretching a critical part of the process?
APEowner said:
I wonder. Do you get the same results if you heat the tires in an oven or is the stretching a critical part of the process?
I’m pretty sure they need to be adiabatically heated through deformation. Just heating it up will not have it go through the structure changes that the material matrix needs to go through.
I believe tire rack pushes the spinning tires against a roller to heat cycle them.
Straight from tire rack’s heat cycling page: “Our heat cycling service begins by mounting the tire on an appropriate-width wheel and inflating it to the desired pressure. It is then placed in our heat cycling machine which has three rollers positioned at the corners of a triangle. The tread flexes where it comes into contact with each of the rollers, stretching the rubber compound enough to progressively bring it up to temperature all the way around the tire and across the tread.”
We started buying pre heat cycled tires. It increased our tire life by 50% or more. Especially important before getting the wheel/tire package dialed in.
For decades many race teams have “scrubbed” sets of tires during test days for this very reason. Even Crashcar teams do it. Teams I worked for would use the Thursday test day for the Daytona 24 to scuff multiple sets of tires.
Twenty years ago I was working with a special compound tire supplied to me for an important race. The tire engineers told me to scuff them before the race, and let them cool back down to air temp. In this case we had only two hours between a warm up session and the race. I’m sure many were laughing at us as we dismounted the wheels and carried them to a hose to rinse them repeatedly to get the heat out. (It was silly looking) But, all that said we won the race and set a lap record.
Its probably why I have no issues with any of my Falkens. Go out and run them pretty hard and come home and park the car up on jackstands for a day
A fresh set of heat cycled Azeenis RT660’s are going on the Miata as I type. I think paying for heat treating is the cheapest speed and durability you can buy.
What does “scrubbing” a tire in on track consist of? 6/10ths for 3 laps? One warmup and one flying lap? Curious!
My NT01’s typically get heat cycled by sliding them around as much as possible on the out lap and then usually a quick spin/4 wheel off to cool them down. They never last less than 13 or 14 weekends this way and always keeps the marshall on their toes.
I continue to be amazed by having to do all this extra work. Every single customer will want at least 2, if not all, of the benefits (improved lap times, longer service life, reduced wear). Do it before it leaves the factory, add $20 to the price and let’s be done with it. Do an “easy session” you say? Is that why I put all this time and money into this car and this track day (and into bribing the moderately jilted wife)…so I can do an easy session and then put the tires away?
APEowner said:
I wonder. Do you get the same results if you heat the tires in an oven or is the stretching a critical part of the process?
Yeah the tires really want to get the heat through deformation and friction. This exercises the entire structure of the tire and leads to more even heating and more aligned curing after they return to ambient temperature. If you had no other alternatives, heating with tire warmers is better than simply doing nothing as it does allow the tread surface some benefits, but it’s no substitute for proper friction-based heating.
buzzboy said:
We started buying pre heat cycled tires. It increased our tire life by 50% or more. Especially important before getting the wheel/tire package dialed in.
I had the same experience. I started having Tire Rack heat cycle my HPDE tires a couple years ago and I’m getting 50-75% more life. Definitely worthwhile.
Why aren’t tires heat cycled at the factory? Good question. As these tires are often made in small batches, I wonder how much heat cycling would impact shelf life.
Tire “life” starts at first use, not when they leave the assembly line. If they get heat cycled and then sit in a warehouse for six months before you buy them, that’s six months taken off of their useful life. Unless you have a dedicated track only non-street legal car, it’s really not too hard to do a decent heat cycle on the street (and it’s free).
In reply to dps214 :
I get 14 heat cycles out of the Hoosiers on the Datsun; that equates to two race weekends plus two additional sessions.
I use Friday first practice session to heat cycle the new tires then put the old tires back on for any additional sessions.
If I’m not doing Friday practice I heat cycle the new tires at a track day event; I usually have a track day within a month of a race weekend
In reply to MauryH :
The Hoosier guy told me it is a key element of doing it properly.
Can anyone provide insight into the tire categories which benefit from heat cycling? For example, only Track and Comp DOT tires, or will an Extreme Performance Summer Tires also benefit? And Max and Ultra High Performance Summer tires?
Thanks
No mention of the cooling down and 24 hour wait period process. A extremely important part of the entire heat cycling procedure……
RWRhein said:
Can anyone provide insight into the tire categories which benefit from heat cycling? For example, only Track and Comp DOT tires, or will an Extreme Performance Summer Tires also benefit? And Max and Ultra High Performance Summer tires?
Thanks
We started off racing on All Seasons(due to weird OEM tire size) and we were having them heat cycled. That was my original 50% tire life increase. Shaving was another probably 25% life increase.
In reply to maxxturbo :
I thought JG covered it well. Just don’t touch them for 24 hours and you’re set.
In reply to RWRhein :
The theory is the same for every tire, which means the only difference is whether or not the starting performance envelope is close enough to intended use that expanding it will be noticeable. You probably still won’t be happy trying to do time attack on all-seasons, but we heat cycle almost every tire we run.
