Why is my trailer more stable at 60-65 than 50-55? | FerrariChat

Why is my trailer more stable at 60-65 than 50-55?

Discussion in 'General Automotive Discussion' started by Sandy Eggo, Jul 31, 2010.

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  1. Sandy Eggo

    Sandy Eggo F1 Rookie
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    #1 Sandy Eggo, Jul 31, 2010
    Question for you physics majors or truckers...

    Why is my tow vehicle and trailer more stable at 60-65 when it gets all nervous and sway happy at 50-55? Seems more speed would make the swaying worse but it is quite the opposite. Any good explanations out there?

    Fwiw, I'm pulling a 7,000 lb trailer (26 ft) with weight distribution hitch and sway control bar. Tow vehicle is 2010 Navigator with tow package.
     
  2. UroTrash

    UroTrash Three Time F1 World Champ
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    #2 UroTrash, Jul 31, 2010
    Harmonics.
     
  3. ryalex

    ryalex Two Time F1 World Champ
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    #3 ryalex, Jul 31, 2010
    Last edited: Jul 31, 2010
    Also, possibly tire and wheel balances could be off slightly causing gyration. When a wheel is out of balance it may shake or shudder within a range of speeds (rotations) but that effect dissipates at lower or higher speed.
     
  4. shakazulu12

    shakazulu12 Formula Junior

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    #4 shakazulu12, Jul 31, 2010

    ^^^^^This, start easy and check your tire pressures, but sounds like a wheel weight or balance issue.
     
  5. CornersWell

    CornersWell F1 Rookie

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    #5 CornersWell, Aug 1, 2010
    It's also possible that the aereodynamics are better at one speed than another.

    CW
     
  6. Auraraptor

    Auraraptor F1 World Champ
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    #6 Auraraptor, Aug 1, 2010
    ...which when off only slighly results in very noticeable vibrations due do the manifestation of...

     
  7. Pass

    Pass F1 World Champ
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    #7 Pass, Aug 1, 2010
    Tongue weight is going negative for some reason; probably due to aerodynamic forces. When tongue weight is negative trailer will start to fishtail but if you apply acceleration it will overcome the fishtail. I would check into that possibility.
     
  8. ryalex

    ryalex Two Time F1 World Champ
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    #8 ryalex, Aug 2, 2010
    Which you can check with a handy harmonica.
     
  9. Sandy Eggo

    Sandy Eggo F1 Rookie
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    #9 Sandy Eggo, Aug 2, 2010
    Thanks for all the replies.

    I'm thinking it's a combination of aerodynamics and possibly the "harmonics" theory.

    The tire pressures are good and wheel balance seems to be fine - I know the feeling of an out of balance tire/wheel and this ain't it.

    During the 1,000 miles of towing I did this past week, I noticed that it wasn't always so much about the speed I was traveling but also the wind speed/direction played a big role.

    Maybe the best idea is to just buy a truck and forget about it! :D
     

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