I have a roll bar, and still have the shimmy. Been there since I bought it.

 

I'm curious to see if the BossFrog Arms make much a difference. This winter I plan to add them and a strut brace for stiffness. I'll report back on whether they help with my shimmy shimmy.

 

The frog arms are one of the better stiffening products supposedly. Roll bar and door bars are up there.

If you don't think you have the shimmy, try loosening up your grip on the wheel at 55-75mph. I bet there's one somewhere in there. Mine's hard to notice when I'm white knuckling the wheel.