I experienced the same thing, running E36's on the side and had quite a bit od shake. Dropped front end about 6mm by loosening triple clamps and letting the fork tubes slide up a little, that helped quite a bit, alot less shake. I think I'm going to try the rear shock wwsher shim next to raise back end, then play with sliding the fork tubes back down. Definately want to maintain ground clearence when riding two up and loaded.