Questions

I was checking out some tires and this fella starts telling me that certain tires are "track tires" and that after 30 or so "heat cycles", the tire will begin to turn blue, the rubber will become harder, grip will diminish, and it will be useless, and that it doesn't matter how hard the tire is run, even if you drive the car a few miles, that's one cycle.

As an example, one of the tires spoken about were Nitto's NT05 as an example of a "track tire".

Is this true, "track tires" have only about 30 heat cycles in them and will be useless on a DD within a month?

97W202

sounds like you spoke to a complete idiot.... any experts correct me if I am wrong

Luke@tirerack

I will happily correct you when needed .... this, however, is not one of those times

Questions

Thanks guys.

Luke, are there any situations where there might be some truth to his statements?

Luke@tirerack

I guess if a tire is repeatedly over-heated 30 times it would have a detrimental effect on the rubber compound. A tire will turn 'blue' on the edges because of heat and heat cycles but, that does not mean that there is any appreciable difference in the durometer of the tire and it tpically takes more than 30 heat cycles .... I guess we would really need a definition of what he considers a proper "heat cycle". If he is using the theory 1 track day with a 24 cooling period is a heat cycle then he would be correct. Few, if any, DOT r-compound tires will last 30 full track days. If his idea of a heat cycle is 1 Auto cross run or one trip down the drag strip then his statement loses most of it's validity.

I ran a set of Michelin Sport Cups for several thousand miles with a few long road trips, several track days, and more AutoX's than I can recall and they never heat cycled out but, they lost a significant amount of grip once I started seeing cords