Choosing a bike best fit for you doesn't really depend on your size. When buying a dirt bike this can come down to many different factors. The first depends on your experience. If you are a fairly experienced rider then a faster bike would be better. But if you have hardly any experience you would be better getting a smaller bike. Next is size. If you are a big kid then a big wheel bike would fit better. A big wheel bike is a small CC engine with bigger tires and suspension.