my 01 has done 70 w/ 47 rear sprocket. bike is definitely not happy @ that speed: a little twitchy (maybe that was me). much happier below 60mph.I now know my stock (for now) TW will do 70mph flat out with my 190lb butt. My wife called yesterday with chest pains. Shes fine, bruised rib, probably from my 1 year old boy playing a little rough.