Question: what is the best size dirt bike for a 11 year old?
Answer: For a 10 11 or 12-year-old average kid that wants to learn to ride dirt bikes and he or she is not too much into racing or a serious motocross I would recommend Honda CRF110F, which is the bike that my nephew rides, following by the Kawasaki KLX110, or the Yamaha TT-R110E model.