I'm only 15 and i've been riding since i was 5. You'll be all set moving up the the 400ex, but if you've got riding buddies who are older and more experienced with sport quads, i wouldn't try to keep up with them just yet, get used to the bike, although it doesn't take too long with a 400ex.

RIDE RED

 

Im 13 5'6 130#. This is my second quad and I am already looking for a pipe. You will have no problem.