For the last 5 years I had it mounted to the frame at the rear but the tyre finally wore through it so now I made ups some brackets out of 15mm copper tube and mounted it to the swing arm.
I used the aluminium "crud catcher" as a template to cut the plastic mudguard down so it protrudes well below the swing arm at the front using the existing bolts and extending the rear with a rubber mud flap.
Rivnuts were used on the swing arm and rubber rivnuts on the mudguard.
All seem fine up to press.
I would add some photos if I knew how.