I'm getting ready to purchase auto-x tires. I notice that you can purchase them heat cycled. Sounds like a good idea. Do most auto-xers purchase their tires heat cycled ? Thanks.

 

It can't hurt, but the heat cycling may not be sufficient to be significant. The best method might be to take it easy on the tires during the first event. I was unimpressed with the results of Tire Rack's heatcycling when the tires were used on hot, abrasive concrete.

 

I did my last set myself. A little over 100 miles of steady highway to get them up to temperature and then pulled them off the car to cool for two days.

EDIT: Found that this was not very effective and have used the figure eight technique with more success.

 

The heat cycling that some tire distributors offer really doesn't do anything. (Of course, this is MY opinion, and I'm sure there will be people who will tell me I'm full of "something".)

To heat cycle a tire, you need both heat and abrasion...something to do with rearranging the rubber compound molecules. Anyhow, the typical roller-type (like a dyno roller) heat-cycling machines are only 195mm wide...so what happens when you put a wider tire than that on the machine? --> part of the tire isn't "heat cycled".

Bottom line is...only effect way to properly heat cycle a tire is on the car and on the track...

Andie

 

Great information! Thanks. This machine is typical of Tire Rack's machine? In any case, I can see one can save money easily diy.

 

If you want to heat cycle your tires, DO NOT do it at the track, because you can't unless you are going to be there for 4 days and only plan to drive for two.

The best method is to put them on the car, go drive 100 to 150 miles on an expressway at normal driving speeds. Drive home, jack up the car, remove them and lay them flat on the garage floor, do not stack them. Now the hard part - don't touch them for two days. after two days of sitting they are heat cycled.

Or spend the money and have someone else do it. I have always done it myself and have found major differences between tires that were not done and tires I have done.

http://www.tirerack.com/tires/tiretech/com...atcycletech.htm

 

I thought I was being clear, but apparently not.

For heat cycling at the track, the gist is that you put them on the car, cycle them in, and then take them off, and put on the next set you want to heat-cycle. I was not trying to imply that you can just put them on the car at the track, heat-cycle them, and then continue to drive on them for the rest of the day.

Sorry for the confusion. -Andie

 

I don't think 1 hour of highway driving equals 15 minutes of track use. The only way to get the tires to temperature is by braking and cornering at the limit of traction. Hoosier specifies that this should be done gradually, but the last lap should be at full speed. I think highway driving only heat cycles the tires for highway driving.

 

The idea behind heat cycling is to gradually bring the entire tire up to temp slowly and evenly. Track use will not heat them up slow or gradual, expressway driving will.

The heat cycle process is a molecular change of the materials. The slow even raising of the temp allows the entire structure to "squish" together and form a more complex bond. Pushing the tires hard on the track for 15 minutes is going to do one thing for the outer edge of a front tire and a completely different thing for the inner edge of a back tire. This will not create even warming. Driving consistently on the highway allows the entire contact patch and eventually the sidewalls of all 4 tires to just nicely come up to an even temp. Again the key word here is even and gradual.

Track use is not the way to do because the corners will loading up the heat on the sidewalls will not create an even distribution.

 

I suspect that there's some / a lot of variance in technique and results and may well vary from manufacturer to manufacturer. The simple way to do it is to raise the temperature to something in the working range of the tire's design. This, along with flexing, will break longer molecules into a more consistent size. It's the consistent size that apparently helps the wear characteristics.

I've wondered how cornering and other flexing done other than in the longitudinal direction would affect the result. It appears that it may not make much/any difference, perhaps because other factor lead to the tire's demise before the effects could be seen. There would also be an issue of cornering causing higher temperatures on the edge rather than a uniform temperature across the face. Possibly road-racing usage would demand cornering since the alignments and time per event would be the significant factor while autocrossing would be short temperature spikes of uneven temperatures.

The only way to really tell is to try them all. I'd go with the tire manufacturer's recommendations or, lacking anything else, the 100 mile road trip...