i dont know... i started on a 600, but i knew my limits. for sure! i rode the thing like it was a 250 though. i would say its more of a mindset than anything else. like a im to cool to wear my helmet and jacket so im gunna slap on my oakleys instead type of deal. and someone who rides way above their own skill set. i am sure there are other examples, but what it comes down to is the mental aspect of the rider.