I have not personally stripped any karbonite gears, but a friend of mine had used HS-635HB as aieleron servos and without even flying it hard, just a high rate roll at a low speed caused the servo to strip. Then on landing the other aieleron servo stripped. I am using two of the HS475BS Karb gears in a .40 size Extra, I have two flights on this one and have not had a problem yet. But I will keep an eye on it.