RE: All you Gee Bee people reply!
Tom,
The Dave Brown 4" wheels are too big for the material that they are made of. There is too much unsupported foam for the tire. This was causing me two problems. First, the soft foam was acting like it was rolling in mud, creating drag that would make the plane flip over. Second, instead of just compressing, the foam would deflect to one side of the other. The tire was catching on the sides of the wheel pants and causing drag that would flip the plane.
Also the gee bee is too heavy for them. If you let the plane sit for even a minute, the wheels flat spot. So you then have this flat spot that will create drag.
The Sullivan Wheels are made of a much harder foam that won't deflect sideways, it rolls much easier, and it won't flat spot. I picked the 3.5" wheel because that is the size that the hobby shop had 2 of at the time. I would have preferred the 4" because that it is the specified size, but I havn't had any problems.
Ben