servos, servos, servos, everyone has a different story. i've had 4 blue birds and 1 still works. best $40 servo i've tried but for $80 you can get an ace 1013 that is the best high end-low price servo you can get. i spent over $200 on other $10-$40 servos in 1/2 the time i've had my ace. servos are the meat of your ride so don't skimp on that if you can.