Mine's a 9 tooth. I just feel like I have no hard lift. As far as wasting your money on carbons, I've smacked my blade on the ground about six times with them on and they took the abuse. Touch the ground with woodies and you have to buy a new $et. Once I repaired them due to an asphalt strike. The shaft is straight and I don't have any vibration. ( I replaced it once!) I wonder if my motor is starting to slow down, it's over a year old with at least 50 flights. I still haven't replaced the tail motor! I may get a set of woodies at my LHS www.Hobby-Sports.com. I love to give them a plug once in a while, they've never let me down I'll let you all know how it feels going back to the woodies. I'd love to put the 3-1 in and go brushless, I'd be very happy.