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Wheel weights and balancing: Anal Question of the Day

Discussion in 'Technical Q&A' started by Bullfighter, Nov 26, 2007.

  1. Bullfighter

    Bullfighter Two Time F1 World Champ
    Lifetime Rossa Owner

    Jan 26, 2005
    20,698
    Fullerton, California
    Full Name:
    Jon
    So...

    On my car, the wheels are all balanced with weights on the inside rim of the wheel -- nice because they're not visible. Not sure if this was a coincidence last time the tires were changed, or some obsessive owner threatening the tire jockey at gunpoint if any weights marred the rims.

    If I ask the the tire guy locally to balance the wheels from the inside, will he start throwing heavy tools at me?

    I notice that all my new cars have had the weights mounted inside, so there must be some truth to the 'balance it from the backside' approach.
     
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  3. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    20,267
    socal
    Do you really want to know the answer to this question? O.K. here it is...

    There is dynamic spin balancing and there is static balancing. You always pay for dynamic spin balance but 99% of the time get static balance. DSB is balance in the X/Y plane. SB is balance in the Y plane only. Therefore if you put weights on the inside you may or maynot get weight in the proper place in the X plane or you need more weight in the X plane to accomplish the job due to shirt lever arm of not putting the weight on the outside visible face which will require more weight in the Y plne to balance the wheel. So if your tire monkey is 1) not entering the overall diameter and width of wheel, or 2) sticking weights on the inside middle or inside edge only you are getting SB only. SB is fine I do it with race wheels all the time and it make little difference at 120mph. Sometimes you get a wheel/tire combo that really needs the proper balance and sometimes you even need to "force" balance (need special machine) which is a balance done with the tire under load. IMO there is a 90% chance you will not feel the difference between DSB and SB. Besides there is a 90% chance you have never had a true DSB because of eitehr of the two above reasons. Well I hope that helps.
     
  4. spiderseeker

    spiderseeker Formula 3

    Jul 22, 2005
    1,708
    Colorado
    Full Name:
    Steve
    Because my rims were just refinished , I asked for my wheel weights to be on the inside. The tire guy said "no problem", that as long as the wheels were straight and tires were ok (new F1's), the balance should be fine that way and they are perfect to 100+ mph. (I hate seeing wheel weights, if it's not absolutely necessary)
     
  5. bls2219

    bls2219 Rookie

    Oct 3, 2007
    30
    Boerne, Texas
    Full Name:
    Bill
    When I had new Pirelli PZeros mounted on my new repro 16" wheels, I asked the tire guy if they put the weights on the inside. He said "Of course". They did a spin balance on their machine and the weights are close to the middle of the wheel.

    Everything seems to be okay.
     
  6. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
    2,159
    Tampa bay
    Full Name:
    Bruce
    Exactly! Wondered how many people knew or understood this.
     
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  8. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,234
    Houston, Texas
    Full Name:
    Bubba
    I have white wheels on the Trans Am, when new they put them inside, after a few years they bang them on the outside and I paint the lead...LOL!

    As noted, the stick on ones can be mounted anywhere....
     
  9. miketuason

    miketuason F1 World Champ
    Silver Subscribed Owner

    Feb 24, 2006
    14,286
    Cerritos, CA.
    Full Name:
    Mike
    I didn't understand it that clear until now but I have always make sure in the past that they do the DSB (weight both sides) everytime I take my wheels for balancing.
     
  10. Bullfighter

    Bullfighter Two Time F1 World Champ
    Lifetime Rossa Owner

    Jan 26, 2005
    20,698
    Fullerton, California
    Full Name:
    Jon
    Perfectly.
     
  11. KKRace

    KKRace Formula 3

    Aug 6, 2007
    1,052
    Rockville/Olney MD
    Full Name:
    Kevin
    If you go to a decent shop that has a high end machine there are settings for putting the weights on the inside only. When I mount them myself I try to use as few weights as possible. The older machines just assume you can only put weights on the outsides of the rims and if you look at the results and make a educated guess and put the weight in the middle and retest and often it will be perfect. If I'm mounting and balancing myself I'll spend some extra time and try to rotate the tire on the rim a little and most of the time get pretty good results without having to add much weight. Competizione in Maryland has one of these machines that allows you to spec only inside weights.

    Be carefull where you have tires mounted! Most of the tire shops have trained monkeys mounting and balancing tires. You'd think that if thats all they do every day they'd be good at it but most of the time thats not the case. Worth finding someone decent if you have hard to replace rims! Also, if they are using an airgun to put the wheels back on your Ferrari go somewhere else!

    On my FCar I'd rather have a tire wear a little funny then put a weight on the outside and screw up the paint on my rims. The tires will probably dry rot before they wear out anyway.
     
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  13. prance

    prance Formula Junior

    May 4, 2005
    510
    Agoura Hills
    Full Name:
    morris
    I always have the weights wherever they are required. For reasons already stated I don't believe that you can have a well ballanced wheel with the instruction that the weights be placed on the inside only, especially with older cars with wires.
    Morris
     

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