I can see the point if it doesn't have a derailer (just loosen the wheel, move the chain over, tighten the chain and wheelnuts, as opposed to fliping the wheel over), but as a shift-on-the-fly, it seems pointless. Why only two gears, why not 8 or 9 like MTBs? Why would you want to change gear in a BMX race anyway, especially two so close together? Why all the extra weight? Stupid if you ask me.