Seatpost clamp style bike work stands work really well, but they're expensive and can be overkill. Scorpion's MTB Pro Stand, on the other hand, costs less than your race entry fee, is easy to transport, and is super simple to use. Just slide the arm into the hollow spindle of your mountain bike and get to work. The Pro Stand's design will lift your rear wheel off the ground whether its 26, 27. 5, or 29in, so you can run through the gears easily, and the construction will support up to 50lbs, so even the burliest DH rig won't tax it. Scorpion also included arm adaptors, so the arm will work with whatever spindle setup you're riding.