I'm about to complete my own bushhog (see attachment.) Only work left is to add the tires (if I really have to add the tire.) I suppose the height of the cutter should be flexible(automatically adjustable) according to the shape of gorund surface. I say this flexibility in the cutter height should be elastic (reversible to its original height quick). But plastic adjustment too makes some sense as tractor is moving together with the attachment. Maybe, I should ask this question like that "solid tire or pneumatic tire" (ps. no laminated tire as I don't favor it. Am I correct? You are experienced cutters;-)