I have a 6 year old boy and a 3 year old girl. He rode a bike on 2 wheels at 3 years and a pw 50 at 4 years. He did great and loved it. His sister rode 2 wheel bike at 2 years old and got his old pw 50. No training wheels. He rides a klx 110 now and could already use a kx 65. She is still 3 and has used up the pw, now she is on a 05 crf50 and does not have any problem. She doesn't shift it yet, I put it in 2nd gear and let her go. It is better than a 2 smoke, it doesn't load up if she wants to go slow and it has a suspension. It's also a little taller so she won't grow out of it as fast and they probably hold there value better. We ride on a track at a local dealer and around our yard and they both love it. Every day I hear,"Daddy, can we ride our dirtbikes?" Enjoy, I know I do.