Heat Cycling Tires

[Robert Joe]

Does "Heat Cycling" apply to kart tires? Should you heat cycle new tires by taking them out for one session and then cool them down for at least 24 hrs after which you can use them as normal. If so, how many laps and how hard should you drive for the heat cycle session?

[Sean Robbins]

I'm not sure if we're talking the same thing, but in most cases "heat cycling" the tires leads to eventual tire hardening, which is bad for performance. True, you may want to scuff the tires up a little bit by running a lap or two to put a little texture on them, but this has little to do with getting them up to temperature for a certain period of time.

True, warmed up tires stick better than cold tires, but this is talking about current, and not historical temperatures. (case for tire warmers)

Look into getting a tire durometer and you can see how the tires harden over time.

[tim webb]

I think Robert is asking a different question. Goodyear and Hoosier, only race car tires I have experience with, both suggest that the tire should be heat cycled or run-in before racing with the tire. This requires one session on the tires starting slow and building speed to get the temp up to optimum on your last lap. The point is to raise the tire temp up gradually.

Once you are up at the propper temp, head to the pits and remove the tires from car. Let the tires "cure" for 24 hours or at a minimum let the tires cool to ambient.

In theory, the tires will perform at their optimum for a longer time if the run-in procedure is performed.

You can go out and flog the tires straight away, but tire life is sacrificed. Do kart tires need the same treatment?

Tim

[Robert Joe]

Thanks Tim for clarifying my question. Here is a link that describes heat cycling:
http://www.tirerack.com/tires/tiretech/heatcycletech.htm

Note a lot of people do not use this service and heat cycle themselves by driving their car and then letting the tires cure for 24-48 hrs.

I'm just wondering if anyone has done any experiments with kart tires? I wonder if the F1 or Indy cars do this?

Since it can't hurt, what I will do in the future is put on new tires for my last practice session of the day, then by the next time out they will have cured.

[Bob Chiras]

Heat cycling does definitely harden the compound of the tire. It does not continue at the same rate as you use the tire over and over. The exposure to the suns UV rays with the kart on the stand in the pits also hardens the compound and deminishes grip.

The question you have to answer for yourself as a racer is do I need less or more grip from the tires on my kart. If you need less then cycle the tires if you need all the grip you can get then go with the stickers.

To run at the front requires a different thought process in tire investments.

You should all remember that durability is not a characteristic in the tire manufacture process of race tires. Consistency is also another characteristic which is seldon maintained.

Take durometer readings each time you purchase tires. Then measure the size of each tire. You will be amazed at the differences within the same case of tires.

Quality control is not heavily applied to a product for which there is no warranty and who's objective is to wear rapidly.

[Patrick Hubbell]

quote:

---

Originally posted by Robert Joe:
Does "Heat Cycling" apply to kart tires? Should you heat cycle new tires by taking them out for one session and then cool them down for at least 24 hrs after which you can use them as normal. If so, how many laps and how hard should you drive for the heat cycle session?

---

I spoke to a Bridgestone engineer once who told me that tires should be scuffed in and run up to normal operating temperature 24 hours prior to racing on them. Somthing to do with aligning the molecular strands within the rubber.