I have a LawnBoy Commercial self-propelleded 21" hand mower that is used daily, and sometimes for long periods of time. It is a couple of years old, and I had an older model that ran for years (pre-DuraForce). My experience has been the drive wheels don't last very long - the rubber wears off. I change wheels about twice per season. The last set of drive wheels I mounted have developed a problem. The plastic hub, with the metal gear pinned on the inside, is no longer adhering to the outside rubber tire. It spins within the tire. Of all the wheels I've had, this is a new problem. And, it has happened to both wheels, about a month into service. Oh, to be sure, not a huge problem, but the wheels are expensive! Maybe these two came from a bad production line. The wearing surface on the rubber is still good with lots of life left. So, I don't want to throw them away and start with a new set. Is there any mechanical way to make the attachment that others have used? There isn't much room on the inside for a bolt head (e.g. putting a bolt radially through hub and tire). How about some glue? The wheels drive fine on flat terrain, but if more power is needed to climb a slope, they will spin, leaving the tire stationary (and me pushing the machine!).