The colored dots identify the final finish inspector that inspected that tire. We used to use yellow paint stamps with numbers but the numbers were usually illegible. When we got back a tire that should have never shipped to begin with we often had trouble figuring out which of our inspectors needed a tad more training. Now they each have a different color paint pen.
Race tires are not warranted as racing is often performed on severely underinflated tires. Additionally, the use of softeners, which we strongly advise against for safety purposes, can lead to tread blisters and tread and ply separations. Tires are regularly inspected on return to us and any product showing a defect in workmanship or materials is replaced. Our inspectors are very skilled at differentiating between damage and defect. Returning a tire you have damaged and claiming it to be defective is a waste of our time and your money.
American Racer Tires are manufactured for a specific application (racing, pulling,etc.) We keep the weight down while maintaining enough strength to ensure that the wheels survive their intended purpose.
Racing Tire Manufacturing
Building the top racing tires in America requires the best of men, materials and machines – all of which are found in the American Racer tire manufacturing process.
To begin, we blend the raw materials provided by nature and by man – latex from trees, sulphur from the earth, carbon black from oil & gas, fabrics from plants and chemistry. All of these are brought together to be at the ready for the manufacturing of American Racer Tires.
If the stock is destined for tire treads, sidewall or bead filler, it is taken by means of conveyors to the extruder, or tuber, where warmed stock is fed into the barrel mouth and forced by screw into the head and out through a die. The die has been carefully made to obtain the shape and thickness desired by the tire designers. From the tuber, the treads are sent to the skiver where they are cut to exact lengths for use in tire building.
If the stock is to be used in the carcass of the tire, it is sent to the calender. Tire cord fabrics, cushion stock, and the inner-liner stock are all prepared at the calender. Nylon, polyester, Fiberglass®, steel, Kevlar®, and rayon cord is purchased already coated with an adhesive to give a better bond between the rubber and the cord.
The adhesive treated fabric then goes through another process called calendaring where rubber is squeezed around the cords to insulate them from each other and make heat-resistant tire plies. The rubberized fabric is cut mechanically on a bias cutter into the proper angle and sized ply strips. In the tire building operation, these are laid at alternating angles, or biased angles, to give the tire body maximum strength. The angle chosen by the tire engineers is aimed to meet the verifying requirements of comfort, inflation and driving stresses.
The first step in our custom tire manufacturing process begins with the weighing and measuring of the raw materials which go into Banbury mixers. Following a formula which has been developed, tested and perfected in our laboratory and on test vehicles, the compounder prepares the ingredients for mixing.
The Banbury mixer is used to combine all the required ingredients. The composition of a tire tread stock, for example, is rubber (natural and synthetic), carbon black (to give strength and abrasion resistance), sulphur (which causes vulcanization), accelerator (to speed up vulcanization), age resistors (to minimize the effect of sunlight water and air), zinc oxide and stearic acid (to help activate the accelerators and aid in processing) and oils (to aid processing).
Mixed rubber must be given further mixing and kneading – this is accomplished on the mill where the batch is rolled into sheets and worked until it is the proper consistency for the next operation. Here, too, a sample is taken and tested by the laboratory. Depending on the upon the end of the use of stock, it may be sent either to the tuber, bead former or calendar for further processing into treads, beads, plies and sidewalls.
Still another component of the finished tire must be assembled. This is the bead – a wire bundle which holds the tire to the rim. A single strand of wire used in American Racer beads will support a man weighing more than 285 lbs., and a passenger tire bead bundle might contain as many as 25 wires per bead!
The bead wire is bronze plated to resist corrosion and to promote good adhesion of the rubber. It is then coated with a rubber compound and bent around the circumference of a wheel to give the bead a circular shape. Finally, lengths of woven nylon are wrapped around it and the bead bundle is ready to be used in the tire building operation.
Tire manufacturing itself begins on a revolving drum. The operator is a highly skilled craftsman who takes the previously calendered cut fabric (called a ply) and puts it around the drum. After the appropriate number of plies have been put on the revolving drum, a bead bundle is placed on each edge of the drum after the fabric is crimped over its edges. These plies are then turned up over the bead bundle, thus enclosing it. Additional plies may then be put on the drum and turned down over the bead-ply bundle.
The change from a soft, useless rubber cylinder into a tough, resilient tire takes place during the vulcanization or curing process in a mold where heat and pressure fuses the many parts into an integral unit. The non-skid tread design is put into the tread during the curing process by the design cut into the mold. At the start of the cure, the rubber stock becomes very soft so that when the internal pressure is applied, the stock is forced into the cavities of the design in the mold. As the cure proceeds, the heat and pressure vulcanizes the rubber so that it becomes resilient and tough and permanently retains the shape of the tread design. After vulcanizing, the tire is sent to the finishers who inspect the tire and trim it.
As part of our commitment to quality assurance, tires are taken at random from each lot of finished tires for additional inspection and testing. These checks include High Speed and Endurance Indoor Wheel Testing, force required to puncture the tread and carcass using a steel rod, inflated dimensions, balance and x-ray inspection. Only after these checks are satisfactorily completed are tires released to become American Racer tires.
