I know many think that the SX-Fs are a limited use MX bike, but from my experience they are wonderful for off road and trail use. Stripped down, lighter weight, more aggressive suspension and motors that all work excellently. Me and a riding buddy recently moved from FL to TX and are planning on starting desert racing sometime soon. He has a 2008 450 SX-F and I just got rid of my 250 SX and am looking to pick up an 08/09 250 SX-F. The only possible issues I see for desert use are tire selection for a 19" rear wheel and transmission ratios. The plan is to start with some local races, then work up to racing the Baja 250 and if all goes well running the 450 as a team in the 1000 in 2 years. We have both raced MX, supermoto, and hare scrambles and a lot of the riding we did in FL was good preparation for the desert (fast, sandy, whooped out). What are some decent rear tires available for a 19" rim? Relacing them with 18" is always possible, but hopefully not necessary. What are the typical top speeds run in desert races? Is being able to do 65-70 mph enough if you are not trying to be a top finisher, or would it be frustrating and hold you back?