And just to put the carmichael thing to rest (since I hear it any time I complain about being short).
1) Carmichael is 5'5". Even shorter than me. He may even have a shorter inseam than me.
2) His bike is HEAVILY modified to fit his body: shaved seat, custom lowered subframe, 20" front wheel. Anything you can do to shorten it (and keep suspension stock) has been done to his bike.
3) He is 1000x the rider I will ever be. Yes, he can ride the big bikes, but he's got millions of hours on a dirtbike. I can't even begin to compare to his skill. I'm sure I could ride a full-size bike after 5 years if I put 40 hours in a week.
4) He rides motocross, which doesn't involve hillclimbs, off-camber, wet roots, rocks, and twisty turns. I'm sure I could still ride a full size bike on the MX track, but in the woods, at moab, and around here, I die on a big bike. I'd love to see Carmichael ride a YZF450 up AF Canyon or at Moab. I have no doubt he could do it, but it's quite a different story from a MX track or out at the sand dunes.
/rant