Upon closer examination of your excellent pics, the brackets look like they are mounted to the lower fork shrouds. That may be where the slight flutter is coming from, since they are not as rigid as the upper fork shrouds. Thanks again,

--Tom 02 TBA; 130 mains; TBS; Nology Coils&Wires;Unifilter/opened Airbox; -AI/snorkels; -2 baffles;Progressive 440s & Springs