Before the economy went south, we logged almost 2 million miles a year with Counteract Beads in our tires. Speeds varied from stuck in San Antonio rush hour to 72 mph on open highways. 90% of our traffic back then was running empty 50% of the time, and thats where an out of balance situation really shows up. 6,000 lbs on 8 tires with 110 psi will really cause axle hop with out of balance tires. We never experienced such a situation with the beads at any speed. I don't think there is a speed threshold. As for tire size, I don't know. For many years I have traded pickups before the original tires wore out. I just leave the factory weights on them and don't worry about them. My drivers helped themselves to the beads, but none of them ever reported the results.
