What size motorbike for a small 9 year old?

depends on the 9yr. old ability or has he riden at all yet. Go to the Honda dealership if ya can to see in person what they have. Problaby a 50cc would be right. BUT and its a big but, there are many types of 50cc, some slow runners and some that really scream. So depends what he wants to do , trail ride or more aggressive ,like, race speed. some have automatic clutches so theres no clutch involved. It's enough for a begginner to learn the balance, brakes, and how fast/slow to go . The shifting can come later after some experence. on the auto. Another big BUT-- dont get one too small or slow cause he'll outgrow it soon. Kinda depends,,, you know ur kid, a few kids are happy just slow trail riding forever, but i'd say most would soon want a fast, more aggressive bike, .. at the same time it's harder for a beginner to learn right out on the bike with shifting and clutch..hpoe this helps. depends on the 9yr. old ability or has he riden at all yet. Go to the Honda dealership if ya can to see in person what they have. Problaby a 50cc would be right. BUT and its a big but, there are many types of 50cc, some slow runners and some that really scream. So depends what he wants to do , trail ride or more aggressive ,like, race speed. some have automatic clutches so theres no clutch involved. It's enough for a begginner to learn the balance, brakes, and how fast/slow to go . The shifting can come later after some experence. on the auto. Another big BUT-- dont get one too small or slow cause he'll outgrow it soon. Kinda depends,,, you know ur kid, a few kids are happy just slow trail riding forever, but i'd say most would soon want a fast, more aggressive bike, .. at the same time it's harder for a beginner to learn right out on the bike with shifting and clutch..hpoe this helps.