meh... I think the motor spinning in first gear at 6k rpms is the same as it in 4th gear at 6k rpms. Only difference is the transaxle/transmission is in a different gear. Just my 2 cents. Ive been up to 140-145 in my Bird and it wasnt bad at all. Was racing a friend of mine from a roll and sure the hell didnt need to be going that fast, usually I shut down around 120 ish on rolls and 110 or so from digs.