The History of Tire Siping=centerThe History of Tire Siping=leftIf not for the ingenuity of a gentleman named John F. Sipe, the world of circle track, off-road and go-kart racing might not be quite the same. Employed by a slaughterhouse during the 1920’s, he continually experienced difficulty slipping on the wet floors that often existed. On one particular day, he decided to cut slits into the bottom of his shoes and quickly realized that they really helped provide a better grip.

After Sipe patented the process in 1923, he followed by applying the principal to solid rubber tires that were in use at the time but was unsuccessful due to their limited contact patch. Following in his father’s footsteps, his son Harry tried “siping” low pressure balloon tires prior to World War II but experienced little success as well due to their thin tread wall.

By the 1950’s, however, much improved tire designs were developed and found to hold up well to “siping”, which proved to aid traction on roads covered with snow, ice, mud and rain. With the roadways quickly expanding and traffic rapidly increasing, Goodyear followed and obtained a U.S. patent to employ the practice on passenger car tires. It was also proven effective in a study done by the United States National Safety Council (USNSC) in 1978. The study proved that “siping” not only increased traction but also reduced stopping distances. Although the USNSC retracted their recommendations several years later and no longer endorses “siping” due to evidence suggesting that it sacrifices tire life, it is still in practice to this day, particularly in cold weather climates.

Both Michelin and Bridgestone continue to offer all-season tires that are siped right from the factory. Siping along with grooving and needling are popularly practiced in racing, particularly by dirt track racers as a means to quicken lap times. It’s common practice that race teams carefully log how each tire modification is performed along with the subsequent results and racing venue, which is then used for future
reference. Employed to enhance on-track performance, siping is used to help increase heat within the tire. It creates razor blade-like cuts in the tire, which during tire rotation and contact with the track, causes the inside of the sipes to rub against each other and the tread blocks to be more flexible, both effects which result in increased friction and heat.


Allstar Performance offers traditional (ALL10264/10265) and heated (ALL10266) tire sipers to the racing market to ease the process. They also have a wide variety of race tire preparation tools including tire prep stands, sanders and related accessories. Tire grooving has truly become an art, developed over time and through experience by crew personnel. It offers several key benefits, not only to increase traction but unlike siping, it allows the tires to run a bit cooler. The practice removes narrow strips of rubber for the tire, adding more sharp edges, aiding grip and increasing resistance, thus preventing the tires from spinning or sliding. It additionally helps keeps the contact patch clean and free of dirt build-up.


Experienced crew personnel may cut horizontal, vertical or diagonal cuts into tires using a heated tire groover. Available from manufacturers including Allstar Performance, the specialized tool is available in 110- (ALL10770) or 220-volt (ALL10772) powered versions and allows quick, precise grooving. The tool uses V-shaped blades, available from 1/32” to 1/2” wide to accomplish the desired results.

Since the front tires are used to steer and the rears used to transfer power, tires are grooved specifically to where they are mounted on the car. For this reason, rear tires are typically grooved perpendicularly to the rotation of the tire to add forward bite, while the fronts are traditionally prepped with grooves that run parallel to rotation, which reduces steering resistance and adds side bite when turning.

The newly formed grooves also provide additional channels that deliver increased air flow across the contact patch, aiding tire cooling. When performing grooving operations, it is important that rubber is removed from only 1/2 the depth of the tread, as cutting too deep into the tire can cause “chunking” where pieces of rubber can easily tear-off, ultimately ruining the tire.

Needling is yet another method employed by racers in an effort to gain an edge on the competition. A specialized tire perforator, available from Allstar Performance (ALL10550), is used to punch tiny, shallow holes into the tire, resulting in characteristics similar to what siping provides. Needling also creates friction on the tread’s surface and allows the tire to get up to temperature quicker.

Once at temperature, however, it also allows the tire to better dissipate heat when compared to a non-needled tire. Like nearly any labor practice, siping, grooving and needling are often performed with a compromise. While traction may be improved, a portion of tire life may be sacrificed in the quest for quicker lap times.=centerShop Siping and Grooving Tools