Frequently Asked Questions

QUESTIONS:
1. What is the number written on my bias race tire in yellow chalk?
2. Does it matter which way I mount my tires?
3. What are the do's and don'ts when storing Hoosier race tires at the end of the racing season?
4. How do I properly groove my ATV tires with hard and abrasive track conditions?
5. How do I properly groove my ATV tires with wet and tacky track conditions?

1. What is the number written on my bias race tire in yellow chalk? As a result of a tire being bias in design (as opposed to radial), it will have a circumference that varies from tire to tire. This is not something that is unique to Hoosier but is common to all bias tire manufacturers. However, Hoosier has went to the expense of placing a "chalk-mark" on its bias ply tires in an attempt to assist the consumer in making the proper selection when purchasing new tires. It is something Hoosier does that our competition does not. Now, to understand its use, you need to understand a little of the manufacturing process as well.
After a tire is cured, it is removed from the press and placed on a machine called a "post-inflator". On this machine each tire has air injected into it for a set period of time. The amount of air is determined by our engineering department and is not the same for every type of tire Hoosier produces. After a set time period, a tire is then measured and the circumference is recorded. Then a press operator writes the size on the side of treaded tires and on the tread of slicks, in yellow chalk. All Hoosier bias ply tires with a chalk-mark, follow this same process.
Now, how should the chalk mark be interpreted? It should be viewed as a reference point or a guide on purchasing tires by size to attempt to attain a certain stagger. Say for instance, you needed to replace your right front tire. Your car currently has 1" of stagger (with the RF @ 28 p.s.i.) but you want to get 1 1/2" of stagger. The tire you were replacing had an original chalk mark of 86", and had a roll out, of say, 85". Obviously, you would want to purchase a tire bigger than the 86" tire you removed. Most likely, a tire with a chalk-mark of 86 1/2". You have to remember there are many factors that go into what size a tire will actually measure. The ambient temperature that day, the air pressure in the tire, whether the tire is new or old. These are factors that no, one person, controls. You just need to be aware of their existence and work with what you know. The chalk mark does not tell you the circumference of the tire at running pressure, it does not tell you how big a tire will grow to, it tells you that a tire is either going to be bigger or smaller than another one with a different chalk mark. It's just that simple. Bias ply tires, by nature, are going to vary in size, whether you buy a Hoosier or the competition's tire. By keeping good records, using common sense and understanding how the chalk-mark Hoosier tires provide, you will be step ahead in selecting the proper sized tire(s). (Top)
2. Does it matter which way I mount my tires? All Hoosier tires having directional arrows must be mounted so that the tire travels in the direction of the arrow. Hoosier tires having directional arrows will have them on both sidewalls.  Directional arrows may not be on a tire that can have both a left and/or right side application. All Hoosier tires not having directional arrows should be mounted as detailed below.
Every Hoosier race tire has a four character serial code embossed into one sidewall of the tire. All Hoosier DOT tires will also have two additional codes as required by the Department of Transportation. (Example: J7AB 4AX8 3701)
3. What are the do's and don'ts when storing Hoosier race tires at the end of the racing season? Tire storage.
The useful life of a tire, whether mounted or dismounted, is directly affected by storage conditions. Tires should always be stored indoors in a dark, cool, dry room.
DO
1  Remove the tires from the vehicle. 
2. Remove the air from the tires and store them on their side in a cool/dark/dry environment.
3. Place tires in a black plastic bag when stored during the "off-season".
4. Make sure the temperature range in the storage location is between 40-90 degrees Fahrenheit.
DON'T
1. Don't store tires in direct sunlight or near electric motors. (Electric motors emit small amounts of ozone.) Tires need to be protected from light, especially sunlight. Light causes ultraviolet damage by breaking down the rubber compounds. The storeroom should not contain electrical welding or any other equipment that could produce ozone.
2. Don't apply any chemical treatments to Hoosier tires. (It's not necessary and may actually damage the integrity of the tire by breaking down the rubber properties of the tire.) Tires must not be allowed to come in contact with oils, greases, solvents, or other petroleum products that cause rubber to soften or deteriorate.
3. Don't store tires in sub-freezing temperatures for any length of time. (The rubber can freeze and may crack as a result.)