RIM SCREWS OR BEADLOCKS
Mickey Thompson recommends that wheel widths should not exceed 1” wider than the tread width. If you elect to use rim widths 1-2” wider than the tires tread width, M/T STRONGLY SUGGESTS TO USE MOROSO 3/4″ RIM SCREWS and increasing the number of rim screws to 16 per side or beadlocks. Beadlocks only are recommended on any wheel widths that exceed 2” wider than the tires tread width or if speeds exceed 200 MPH. Some M/T tires have “Beadlocks Recommended” stamped on the sidewall of the tire.
MICKEY THOMPSON TIRES DOES NOT RECOMMEND USING RIM SCREWS ON ALL D.O.T. OR NON-D.O.T. DRAG RADIAL TIRES.
PROPER INSTALLATION OF RIM SCREWS WITH TUBE TYPE TIRES
- Begin by drilling 16 equally spaced holes on both the inner and outer flange of the rim.
Note: (Mickey Thompson strongly suggests that you use Drag slick mounting screws only, and that you follow the rim screw manufacturers suggested drill bit size.)
- Trial run the screws through all 32 holes. Running screws in the hole and back out again. A dab of grease on the screw will help.
- Check for any sharp edges that the screw may have pushed out or caused during the trial run through. If any sharp edges are found de-bur and make sure the inner bead flange of the rim is smooth and clean.
- Mount tire and tube. Have an experienced professional install the tire and tube on proper equipment. (Refer to Mickey Thompson Tech Bulletin #2 for tube mounting procedures and Mickey Thompson Tech Bulletin # 8 for proper procedures to check rollout (circumference).
- Before installing the screws, inflate the wheel and tire assembly to 20 psi. Put a small amount of grease on each screw and install into wheel and tire assembly. Deflate assembly to operating pressure. Inspect rim flange and bead area for proper bead seating. If bead is not fully seated, re-inflate and reinstall screws.
- For best results, “Bubble Balance” is STRONGLY RECOMMENDED when bubble balance is not appicable, static balance is okay. NO ROAD FORCE BALANCE ON ALL M/T DRAG RACING TIRES.
- Periodically you should check the wheel for loose screws and inspect the rim bead area to be sure that there is no bead area separation.
Note: It would be good practice to inspect after each pass when you are checking your air pressure.
PROPER USE OF MICKEY THOMPON ET STREET R (Radial) and ET STREET S/S
Some bead/wheel slippage (1/2” or less) may result during the course of a 1/4 mile (or 1/8 mile) drag race. This is normal. Check for tire slippage when you check your tire pressure after each pass. An easy way to monitor slippage is to put a small mark on tire near the bead just above the valve stem on the wheel. After a few runs, the tire should stop moving on the rim.
Excessive Rim Slip
If continued or excessive (more than ½” to 1”per run) wheel/slip is experienced, Mickey Thompson recommends the use of “Beadlock” wheels for ET Street Radials. Bead screws are not recommended and could lead to tire failure and or damage.
The technical information provided in this document is to be used purely a guideline. Due to the many varied and different conditions to which racing tires, wheels and tubes are exposed, and because of the manner in which racing is conducted, Mickey Thompson Performance Tire makes absolutely no warranty, expressed or implied, as to the fitment for a general or particular purpose. Racing Tires are Sold As Is.