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Old 01-13-2011, 01:00 PM
Dag Otto Dag Otto is offline
Join Date: Sep 2003
Location: Las Cruces
Posts: 5,086
Originally Posted by Projammer View Post
The beads are dry ceramic, so adhesion isn't the goal. What supposedly happens is some sort of continuous dynamic redistribution. Personally, it's counter intuitive to me. If you have a unbalanced spinning object and introduce an untethered weight into it, the weight would move to the location farthest from the center, adding to the imbalance.

Further complicating matters is the tire deforming where it comes in contact with the ground shifting the beads around.
My guess:

The variable position of the beads make it almost impossible for the beads to provide balance (which would prevent vibrations). What they do is provide damping of vibrations. Given a certain forcing action, the mass of the wheel system will start vibrating. The fluid nature of the beads makes the mass of the wheel systems a little bit variable (when the vibrating force is high enough to overcome the centripetal acceleration of the beads, decoupling the beads from the forcing action). This change in mass shifts the resonant frequency of wheel away from the frequency of the forcing action.