Benefits of Tire Warmers
Most racers and track day riders want tire warmers to avoid cold tire crashes and to go fast right from the green flag.
It is true that these are two clear advantages of using Tire Warmers, but there are other benefits that are equally important. A Tire Warmer provides the ability to tune and manage tires in the paddock beyond the grip offered on the opening laps:
- Go Fast from the Green Flag
- Set Hot Tire Pressures in the Pits
- Avoid "cold tearing" tires
- Save "Heat Cycles" by keeping tire warm in between sessions
- Tires last longer
Hot rubber grips the track surface better since not only does the coefficient of friction increase, but the Tire’s ability to form the track surface through "mechanical keying" is increased
Set Hot Pressures
Tires will increase in pressure about 20% on the track (ie: 30 to 36 psi) which makes a huge handling difference. CHR Tire Warmers will get your tires surface AND carcass into the proper temperature range (same as you’ll see on the track). Without Tire Warmers 6-8 laps would be needed to get a tire to its proper "hot pressure".
Many of the current race compound tires are "low pressure" tires with psi recommendation of around 22-24 psi. These tires are more sensitive to being at hot pressure before they work properly.
Set the Tire Warmers to the temperature you anticipate seeing on the track, allow them to "heat-soak" for an hour and set the Hot Pressure. When you hit the track, there will be minimal change. Getting your Hot Tire Pressure set on the Tire Warmers gets you going right away
Avoid "Cold Tearing" tires
Taking a 70 degree tire and pushing it hard on the track will increase the very outer surface of the rubber in a couple of laps. However the rubber 2-3 mm down is not yet warm and not as elastic. This causes the outer rubber to grip the track surface and underlying rubber to rip or tear. This shredded look or graining once developed in the tire almost never goes away and basically ruins the tire. By pre-heating the rubber, cold tearing is simply avoided.
Save Heat Cycles
When tires are heated & then cooled, a change occurs that can be seen, measured and felt. On some tires you can actually see a blue haze form over the tire as some "oils" migrate to the surface and oxidation occurs. On other tires one might observe much drier grayish haze depending on individual tire composition. Putting the tire though these hot to cold cycles reduces the tires grip, hardens the rubber and reduces its useful life. A tire warmer can keep tires hot or simply warm (for longer periods of time) between track sessions and reduce the amount of heat cycles a tire goes through. If the tire is to see more than one track session it makes sense not to allow that tire to cool all the way to ambient; this can extend how many sessions the tire can perform at near maximum grip. By operating in this manner the tire’s grip life is increased.
Tires last longer
Taking tires from ambient temperature and bringing them to race temperature on the track may take from 3-6 minutes depending on the machine, track and rider. Aside from giving up speed during these opening laps, it is truly too fast to heat the tire in an ideal manner. For example on a 75 degree day, the rider gets the tire surface hot in 4 laps, which takes 6 minutes. This increase of 100 degrees in such a short amount of time actually "heat shocks" the tire. Race compound tires have several "activator" chemicals in them and get set into motion with heat. Getting the tire hot quickly actually spends or wastes some of the chemicals and tires will lose grip sooner than if warmed slowly on a warmer.
Chicken Hawk Racing manufactures Tire Warmers branded for Dunlop, Michelin and Bridgestone motorcycle tires and works closely with the tire engineers to ensure the ramp up of heat meets the tires needs.