Every year I explain this to an onlooking kid or a judge, I get the same response: "Wait... what the... is that wood?"
For several years, 188 has gone with a very cheap and effective method of making our own wheels. Once the gearbox design is completed and we decide what size wheels are optimal, we simply make them ourselves. A few pieces of plywood, a lathe, and some carpenter's glue do the trick. As you can imagine, the time it takes to make cylinders of wood is well within one night and can be performed by one or two people. We've experimented with a number of things including
metal C-channel (back when that was legal) and numerous rubber treads, which we only have to fasten on with wood screws (they are far enough in that they don't contact the carpet, but still worry rookie inspectors every time). Sometimes we modify the tread's shape for lateral motion. We bolt in a sprocket and Forstner out some material to finish off. People are always surprised by the amount of traction we get from wood and rubber screwed together, but usually don't even realize that our robots have wooden wheels to begin with, because we paint them metallic colours. It looks pretty cool.
Anyway to sum it up, we get awesome traction, wheels to our specifications, and low weight, all for a lower price than getting them made or buying them off the shelf. Ghetto? I think not.