Re: [alfa] vibrations

["skippatnode" <skippatnode@xxxxxxx>]

Joe,
    It's amazing how much energy an out of balance wheel and tire can have!
It can move a lot more than the tire can deflect.  I have seen cars going down
the road with the tires jumping completely off the ground.
    I don't know about your "16 rad/s".  I just made a quick calculation and
in 5th gear your tires are turning about 1/4th engine RPM.  4,000 engine rpms
= 1,000 tire rpms.  Now, some mechanical engineer can figure how much force a
few ounces of mud spinning at that rpm and that far from the center of
rotation would produce.  Then try to hold it down with one corner of a 2,000
pound Alfa and------
    I rest my case!
Skip Patnode
67 Duetto
Norfolk, Va


>snip< What I want to know now is how an imbalanced wheel can make the whole
car shake like that.  It can't move any more than the tire will deflect, and I
would think that any movement that small would be taken up by the suspension.
My rough calculations indicate that the wheel would be spinning at about 16
rad/s, and I would think that the related vibration would have the same
frequency, but it felt higher than that to me.

- -Joe
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