I have seldom found the gears are the point of failure. I have carefully tested alll the servos that have failed me in 049 use. Each time the motor was the failure. Each time it was a motor winding wire that broke between the commutator and the coil windings. This wire, if pulled too tight and soldered during assembly, will vibrate, harden, and break. If one was truly concerned one would open the motor and carefully encapsulate that area with epoxy or hot glue and reassemble before use. That is a lot of work. So I went with HS81 or HS82, in hopes that the wires were a bit heavier and would last longer. I also take pains to mount using rubber grommets. Don't screw them down so tight the rubber looses all flex. Balance the prop carefully.