TUBES AND TUBE TYPE TIRES

When buying tube type tires it is important to understand the reasons behind making a tire tube type and when it is appropriate to run the tire with or without a tube. The following information will help in the decision making process.

1. Air retention

Tube type tires are not guaranteed to hold air without a tube. If a tube type tire leaks, it is not defective. There is a liner molded into the carcass of a tire that seals it and makes it tubeless. This liner is intentionally omitted from racing tires. This is done primary for weight purposes. More on that later.

2. Consistency

Without a tube you cannot maintain consistent air pressure. Even the slightest leakage will cause a difference in the performance of the tire. Therefore if consistency is the primary goal, as in Bracket Racing, a tube should always be used.

3. Strength

The wrinkling of the sidewall that is visible at launch causes the carcass material in the tire to break down over time. The more violent the launch the quicker this break down occurs. Inconsistent 60' times or a drop off of 60' times usually indicate that this is happening. When this happens the tires should be replaced, regardless of the amount of tread rubber remaining. The use of tubes strengthens the sidewall of the tire and keeps this breakdown from happening prematurely, therefore extending the life of the tire. This will save money in the long run.

4. Weight & performance

In some cases it is acceptable to run a racing tire without a tube. When a car competes in a heads up class, unsprung weight is an important factor. Tires and tubes are all unsprung weight. One pound of "unsprung" weight is equal to 8 pounds of "sprung" weight. The average tube weighs about 6 pounds. Therefore, if you eliminate the tubes you have eliminated the equivalent of 96 pounds from the car. For every 10 pounds of unsprung weight removed you may pick up as much as .01 seconds in quarter mile ET.

5. Cost

All natural rubber tubes are expensive. All M/T tubes are made of Natural Rubber and feature a clamp down valve stem. There are some inexpensive Butyl rubber tubes on the market. Even some with clamp down valve stems. Natural rubber is, by far, the better choice. It conforms to the wrinkles better. Dissipates heat better. And it doesn't get brittle like butyl does. Therefore M/T natural rubber tubes offer superior performance and will last far longer.

6. Safety

At a racetrack you must check air pressure regularly. This is important to maintain performance and to insure pressures are not too low. Low pressure can be dangerous.

Never run tube type tires on the street without a tube. Leakage and the prolonged heat build up can lead to tire failure and serious injury or death. This is not a matter to take lightly.

THE BOTTOM LINE

THE DECISION TO RUN WITH OR WITHOUT TUBES SHOULD ALWAYS BE BASED ON SAFETY AND PERFORMANCE. NOT COST!

This is Mickey Thompson DRAG / STREET Technical Bulletin #6.
For more information regarding Mickey Thompson Performance Products ph: 330.928.9092 OR 909.587.0101