My 5'2" 12yr old has has just about outgrown his CFR 100. We do mostly two track with some woods mixed in. I have been thinking about an upgrade. A CRF 150 seems like the next logical choice, but then again I am geting tired of buying bikes every year. What do you guys think about a CRF 230, or is their a better choice. How much of an upgrade is a CRF 150 from the 100, and 230 from the 150.