Looking at building a trail bike out of a 2015 KTM 85 SXS. Yes I know that is not what it is made for but can it be done. I am thinking a fly wheel weight and much lower gearing. Any other ideas? My son is currently on a TTR 125 but he is at the point he needs something with better suspension and power also it is heavy. There just is not much out there for good trail bikes for these 12-15 year old kids. Any thoughts would be appreciated.