My 08 SERK was a wobbling nightmare at 75 plus, when mentioned to the MoCo they change the subject or headed to the lunch room. The have a very old frame and QC problem that has caused very serous accidents. Braces are ok but you have to make sure the wheels in alignment or your just bracing it out of alignment.
A good MC frame shop can help or take a look at Jake at Glidepro's vids on checking it. Be VERY careful as this is a HUGE safety issue! The MoCo slaps bikes together on jig, then if you compalin they have a poorly designed tool that they check it with. Once you get things in alignment the wobble stops, and you feel like your riding a new bike! Be sure to have steering head bearings, swingarm bushings and wheel trueness checked also. The picture attached is the alignment of my bike before correcting, the rear wheel was making a right hand turn 3/4" in every 6' while the front tire was leaned to the left 3/8"