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Tire mounting on a non-safety bead magnesium wheel.

Discussion in 'The Hokey Ass Message Board' started by stank468, Apr 18, 2007.

  1. stank468
    Joined: Apr 19, 2006
    Posts: 139

    stank468
    Member

    I am mounting a pair of bias-ply, tubeless cheater slicks on a set of vintage American magnesium wheels. The wheels have no safety beads... Do I run a tube? I would prefer not to drill holes in the wheels for retaining screws, they were kinda pricey..
     
  2. hotrawd
    Joined: Jan 24, 2007
    Posts: 193

    hotrawd
    Member
    from lima,ohio

    My local tire store won't mount a tire on a non safety-bead rim without a tube.(It's a liability issue). Also,magnesium is porous. Air will leak out through the pores in the wheel if you don't use a tube.
     
  3. Forgive my ignorance, but what exactly is a safety-bead rim/wheel and how will using a tube on a non-safety-bead wheel help?
     
  4. squirrel
    Joined: Sep 23, 2004
    Posts: 55,941

    squirrel
    Member

    see the little ridge about an inch from the outer flange of the wheel, labled at the bottom of the pic? that's the safety bead.

    [​IMG]
     

  5. Does that safety bead help keep the tire from rolling to the interior of the wheel and coming unseated when making a turn?
     
  6. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    Just run a tube. You'll be glad you did. I also coated the inside surface area of my mag wheels with some dp-40 to slow down corrosion.
     
  7. 47bob
    Joined: Oct 28, 2005
    Posts: 625

    47bob
    Member

    I didn't know that; I have tubeless on tube type rims on the front. Something else to worry about. Thanks a lot Squirrel. .....Bob
     
  8. squirrel
    Joined: Sep 23, 2004
    Posts: 55,941

    squirrel
    Member

    the safety bead keeps the tire from coming off the rim when the air goes out of it. I'm not sure of the history of the safety bead, seems to have been introduced by Chrysler in 1940, but they seem to have become common in the early 60s? not too long after tubeless tires came along. My guess is that when a tire goes flat without the bead, the tire will come off or suddenly deflate, causing mayhem. The idea is to make the car more likely to stay under control when you have a blowout.
     
  9. Like Roothawg I painted the inside of mine with DP-40. I'm running them without tubes. I don't have safety beads but have not had anyone refuse to mount tires for me yet.
     
  10. stank468
    Joined: Apr 19, 2006
    Posts: 139

    stank468
    Member


    Is dp-40 an epoxy primer similar to dp-90(ppg)?
     
  11. Rem
    Joined: Mar 6, 2006
    Posts: 1,257

    Rem
    Member

    If your tyre fitters use any sort of lubricant it eats its way through alloy, so the recommendation is to paint the inner surfaces with anything that will stick to the metal. I had a pair of tyres mounted to brand new alloy rims for a bike once, and after 3 months INDOORS the corrosion was eating its way out through the spoke holes! The white soapy stuff is the worst.
     
  12. That makes sense. With the bead the tire would stay at the edge of the wheel and keep the wheel from making contact with the road surface and causing a sudden loss of control.

    Thanks squirrel.
     
  13. ShakeyPuddin55
    Joined: Dec 22, 2004
    Posts: 1,906

    ShakeyPuddin55
    Member

    I run tubes in mine. Dont let them use soapy water on your magnesium when mounting, baby powder does the trick.
     
  14. pasadenahotrod
    Joined: Feb 13, 2007
    Posts: 11,775

    pasadenahotrod
    Member
    from Texas

    The introduction of the safety beaded wheel by Mopar pretty much ended the availabililty and production of non-safety beaded wheels on automobiles. Tube or tubeless was really not a factor there.
     
  15. Duh.... I typo'd. It was DP-90.
     
  16. squirrel
    Joined: Sep 23, 2004
    Posts: 55,941

    squirrel
    Member

    That doesn't add up, from what I've seen...the sources I've found on the internet say that Mopar introduced them in 1940, yet none of the 1950s GM wheels I have laying around are safety rims.

    Or maybe I'm out to lunch....
     
  17. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    Yes, dp-40 is just a different color.
     

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