I replace gear bolts twice a year. I have two sets of gear, both 3" extended, one for Bushwheels and one for my AWB wheel skis. That is easiest way for me to change, jack it up, drop the gear bolts, and bolt on the gear with wheels, brakes and lines all on which have been all serviced and ready to go. New bolts each time I do it.
As said, changing bolts is cheap insurance. I don't put strut bolts on the same frequency. Just use judgement on how hard you are pounding the plane around. The gear bolts take a whipping when you are running on the rough stuff, particulalry skiis.