Conventional (read; shoddy) wisdom would say that they seek out the heavy spot, but what they don't envision is that they distribute themselves all around the inside of the tire and thin out near the heavy spot. The way they're able to do it is because of what they are. 1/3mm ceramic beads that are perfectly round. If you rub them in your fingers they feel like liquid silicone. They never wear out. We should go over to Flounder's house tonight, take off his weights and put some in his tires. He'll think someone fixed his motorcycle.