Originally Posted by NZRalphy
Washing machines use a heavy weight and springs to stop the thing walking across the floor - they also stop and restart if the out of balance is too extreme.
Actually, most top-loading washing machines have a hollow ring that is partially filled with liquid (my guess is just dyed water because it can freeze). The balance ring is mounted on top of the washer's drum. The liquid inside the ring acts as a dynamic balancer, much like how tire beads are supposed to work. The ring does the vast majority of the balancing for the washer's load. Due to the ring containing only a couple pounds of liquid, it cannot balance extremely off-centered heavy loads, especially if there is a broken mounting spring, or if the drum "skateboard" pads are worn and sticky, or if the washer used is on a weak floor.
I'm wondering if the people that are having balancing bead problems just don't have tire, wheel, and suspension combinations that have a natural resonance or springiness that can't be eliminated, or are made worse, by free moving beads (much like a washing machine that is on a weak or bouncy floor). It would be interesting to see if bikes with relatively weak or flexible forks are more likely to have balance issues with tire beads than bikes with stiff forks (like typical sport bikes). I also wonder if steering and suspension geometry plays a part in the equation.
I believe in the concept of how tire beads work, but I also see issues with how it is executed. I imagine rim mounted balancing rings that contain a non-freezing liquid would work better than beads, but the added cost and risk of damage to the ring would outweigh the benefits.