I agree--nothing below 3 iches, at least for me and my field. Right now I have one plane that has wheels smaller than 3 inches (twinstar), and I think they are 2 1/2. The real problem I have with them is prop clearance on grass. On asphalt, it's no problem, but when the wheels sink down into grass, that gives you even less clearance for the prop. I'm fixing to get some 3 1/4's for it.