I had decent results with Plasti-Dip on the mirror balls. It's much grippier than even the RAM ball, so you don't have to tighten the arms as much. Less force on the RAM balls, less deformation. I still loosen the arms so they don't dig into the RAM balls when the bike isn't being ridden.
Tip on Plasti-Dip storage: Once the can is open, keep it in a large glass jar with a screw top. That will prevent the solvents from evaporating.
DIRT BIKES ARE FUN AND INTERESTING