I keep seeing references to "heat cycles" in tire wear conversations..what exactly are ya'll referring to and why is it important?
Thanks for your time to reply to a silly newbie question.
Don

 

I'm no expert but this is what I have read. Sellers like The Tire Rack Mount the tire and run them under pressure/weight to heat up the tire. This allows certain reactions in the rubber to happen under a controlled environment. I suspect certain cross-linking breakdowns and further cross linking. It would be helpful to have a Vulcanization expert at this point. This controlled heating process makes the tire more durable in track/hi-heat environments. Without this "controlled" heating process, excessive heat early in the tire life can lead to more rapid tire brake down.
I invite a critique from others more knowledgeable

 

The “rubber” in modern tires are composed of long chain molecules. The molecules are “linked” together electrochemically and by physically intertwining with one another. Raising the temperature of the “rubber” compound causes the molecules to change how they are linked together and changes the rubber's physical properties. The initial heat cycling of a new tire and letting it rest unloaded for 24 hours or more allows the molecules to re-link in a way that improves the wear characteristics of the tire. Additional heat cycles cause the tire to gradually become harder and less sticky. Different rubber compounds are more sensitive to heat cycling than others. For instance, Hoosiers are very sticky tires but rapidly loose their stickyness with each successive heat cycle. On the other hand, Toyo and Yokohama R compound tires are less sticky new but do not rapidly loose their grip.

 

Without getting into the chemistry, what they are talking about is how the rubber on R compound tires tends to get harder with each time they heat up and cool down. This is a heat cycle. Many race tires will become too hard to run before their tread is used up because they experienced too many heat cycles, Hoosier R6's are a good example. You can literally tap the tread of a race tire that has hardened and it will feel like plastic.

 

You were quicker on the draw, plus you have the chemistry