I recently purchased a GT stomper prime for my 10 year old. Highly disappointed with the quality of parts for the price of this bike. The cranks were to short, 135mm, the front gear was to small, 28 tooth, the wheels suck, and the derailer was the cheapest on the market. So after a new wheel on the back, new derailer, cranks, and a 34 tooth gear on the front my kid can now jump speed bumps and bomb hills with confidence. Needless to say I will never purchase another GT product.