Yeah, that has been discussed in the XP known problem thread I believe. The welds on the fender and bracket are a little shaky if I remember correctly. I was finally able to fix mine by securing the connection with the fender, light, etc but the fender has been removed since I gave it to my son and he changed out the front suspension...
I also had the fender vibration start after 250 miles. When I saw this thread, I looked for a rubber or soft plastic piece to use as a washer. I cut out pieces from an old smartphone cover, & drilled holes in the pieces to match the 1 bolt and 2 screws that directly attached the fender to the bike. Took it out for a long ride today; vibration sounds are gone.
Hi folks!
I fished black shrink tube up and around the chrome wire, the width of the fenders. Then painted the remaining chrome rod a flat black ..
Perfect!
Cheers!