This can be built into a bias-ply tire by adding air pressure andincreasing the circumference, which aids in turning the race car. Or,buy a tire set with a certain amount of stagger already built in.Hoosier Tire features a marking system that enables racers to choose,from a pile of tires, the stagger they need without mounting three orfour sets.
Stagger is the difference...
Stagger is the difference in circumference of two tires on the same endof the car. Measure around each tire near the middle of the tread.Subtract the two measurements to find stagger or "roll out" as it'ssometimes called. Always inflate the tires to race air pressure beforemeasuring.
"The key is to remember that the marks are not what the tire willactually measure," advises Cowan. "They are guidelines to assist inpicking the proper tires. As a general rule, right-side tires willrollout 2-21/4 inches smaller than the mark, while left-side tires willgo 3-31/4 inches below the mark size. Air pressure is the main factorthat determines how much size differential you see from the markedsize."
This simple tip will have a significant impact on the amount of biteyour race car will get.
"A sharp edge is always more effective, no matter the track condition,"Cowan says. "Most of a tire's traction capabilities come from leadingedges of blocks (tread) grabbing the track surface and pushing the carforward. If an edge is sharp, it bites harder. If not, the edge slipsand limits forward traction."
He adds that to get fresh edges, grinding tires is a smart alternative,because it reduces loose rubber and dull edges that break contact withthe track. Another advantage is that it freshens the top layer of rubberon the tire, so it fires quicker on restarts.
This is an area in which you have to figure out what tirecharacteristics will benefit you the most, depending on your race car'ssetup.
"Our rib tire (only circumferential grooves are molded in) isconstructed softer than our LSB (Large Stagger Blocks molded in), so youalways know which tire you have," explains Cowan. "We have found overthe years that softer tires make the car tighter through the middle ofthe corner while stiffer tires loosen the car at the same point."
Tires, as tough as they may look, are quite sensitive to weatherchanges. Keep your tires out of direct sunlight and excessive moisture,as these may cause cracks in the sidewalls and ruin the tread compound.
Although choosing the right tire compound is important, the ability tomanipulate the tread pattern to suit your needs for a particular trackor set of conditions is just as crucial. When done correctly, groovingcan help you get better traction and allow your tires to dissipate heat,which allows you more control over tire temperatures. Cowan and dirtLate Model driver Scott Bloomquist compiled the following.
* Grooving Soft Tires: While not common in longer races, groovingsoft tires may be effective for qualifying or short heats on a wettrack. Softer tires are generally used on tracks that have a lot ofmoisture but not a lot of abrasion. Loose dirt can be cleaned off bycutting more grooves, which improves traction because of the increasednumber of edges available to dig into the track's surface. To preventweakening the structure, only groove about halfway across the blocks ofa soft tire.
* Hard Tires: If you plan to run the high line or cushion andneed to move some dirt, grooving the tread shoulders is helpful. Grooveson the shoulders help clean off some of the loose dirt to get atmoisture beneath it. Siping the shoulders is recommended if you arerolling the tire under when running lower tire pressures on a slicksurface. The sipes can help prevent the shoulder area of the tire fromglazing over and losing traction.