If you are building your SIG Fazer stock? Then they are all right. I have had the gears strip using 225's on Fun-Flys with significantly larger control surfaces than the Fazer. I would still recommend that if you use them, inspect them frequently. I personally have not had any luck with the HS-81 period, even on throttle. I realize that their sucess, HS 225s and HS 81s is purely dependent on how you treat them. I guess that I am too tough on them, but I have torquring my servos!!!