I'm looking for a 2nd wheel set for my 08' and wonder what other bikes might have compatible wheels. I know rims are rims, so I assume it's the hubs & brake rotors that matter. Also, I noticed a WR450 for sale with an extra set of wheels and the rear is a 19" instead of the stock 18". Is that an improvement for dirt, or just a harder to find and more expensive tire ? If I can't find an affordable set maybe I'll just get one for the rear, since that's the one which wears out the quickest and the one I need most to launch me through the "deep & steep" stuff. Does that make good sense?