Besides being required for air retention, Mickey Thompson racing tubes can enhance reaction time, increase stability and helps the tire maintain the proper shape to reduce sidewall shock and deflection.
Note: Always run the correct size natural rubber tube for the application. The wrong tube type and size will always fail.
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 decision to run with or without tubes should be based on safety and performance, not cost.
The following information will elp in the decision making process
- Air retension
Tube type tires are not guaranteed to hold air without a tube. If a tube type tire leaks, it is not defective. Tubeless tires use a liner molded into the carcass for air retention. This liner is usually omitted from racing tires, primarily for weight purposes.
A tube aids in maintaining consistent air pressure. Therefore if consistency is the primary goal, as in Bracket Racing, a tube is always recommended.
The use of tubes makes the tires package more robust. This really comes into play with heavier vehicles running smaller tires. Because of this, they can extend the life of the tire saving 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, like a tire and tube, is an important factor This is especially true when it comes to a limited power combinations such as naturally aspirated engines. One pound of “unsprung” weight is equal to 8 pounds of “sprung” weight. Based on that, every 12 pounds of unsprung weight removed may gain as much as .01 seconds in quarter mile ET.
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 with clamp down valve stems. Natural rubber is, by far, the better choice. It conforms to tire distortion better, dissipates heat, and it doesn’t get brittle like butyl rubber. Therefore M/T natural rubber tubes offer superior performance and will last far longer with the ability to be re-used.
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, serious injury or death. This is not a matter to take lightly.
MOUNTING PROCEDURES FOR TUBE TYPE TIRES
- Check the valve stem hole in the rim. The hole must be 5/8″. Note: If necessary to drill the valve stem hole in the rim, make sure the rim is de-burred and free of material and sharp edges.
- Before installing new tubes pre-inflate the tubes to the approximate diameter of the tire. This will aid in filling the entire cavity of the tire by giving the tube a “stretch”. Note: This will also aid in valve stem placement on wide rims where the valve stem is offset on the rim, but not on the tube.
- Clean the bead and all interior surfaces of the rim.
- Place wheel on tire changer following the equipment manufacturers instructions.
- Mount bottom bead only on the wheel.
- Insert tube in tire and partially inflate to make sure it is not “twisted”. It will help to lubricate the tube with baby powder. If you’re using a liquid lubricant on the bead, do not allow lubricant to run between the tire and the tube. DO NOT use anti freeze, silicones or petroleum based lubricants.
- Align the tube valve with the valve stem hole in rim. Insert and center the stem in the hole.
- Mount the top bead of the tire on the rim so that the bead in the valve area is the last part of the bead to go over the rim flange. Be careful not to pinch or move the tube. Re-center the valve stem, if necessary, by rotating both the tire and tube. After centering the valve stem install the valve stem clamp ring.
- Inflate tire assembly slowly to seat tire beads. Do not exceed 35 p.s.i. to seat beads.
- To prevent tube wrinkling, remove valve core to completely deflate the tube. Reinsert valve core and firmly seat it. It may be necessary to repeat this process to eliminate any wrinkles. Note: See second half of this bulletin for further details.
- Reinflate assembly to proper pressure and check circumference of the tires to make sure they match before installing any rim screws into the tires. (See Tech Bulletin # 4 for proper installation of rim screws)
WHAT TO DO IF YOU FIND “LOW SPOTS” OR “WRINKLES” IN A TUBE TYPE TIRE
You may notice a “low spot” or “wrinkle in a tube type tire. (See diagram #2-A)This can be caused by one of the following:
A. Wrong tube size (too large or too small).
B. Faulty tube installation (wrinkles in tube).
To confirm the problem, you can do one of two things:
- Break the tire down and rotate it on the rim. You’ll note that the low spot, if it is still there, has not moved.
- Break the tire down and remove the tube. Install a valve stem and inflate the tire. You’ll note there is no low spot.
To correct the problem, first be sure the correct tube size is used. The proper tube is listed in the Mickey Thompson spec sheet. To eliminate wrinkles, the tube should be inflated and deflated during installation. If the wrinkle persists, you may need to lubricate the tube with baby powder and/or break the tire down and work the wrinkles out by hand.
Note: If the wrinkles are not removed or the wrong tube size is used, premature tube failure will occur.
This is Mickey Thompson DRAG / STREET Technical Bulletin #2.