31-05-2020, 08:23 AM
Having spent a good few minutes studying that photo, I think that complex design is specifically so that a centre hole in the wheel is not needed. It looks to me as if the inner disc is fitted to the inside of the wheel, presumably located reasonably securely between rim and centre, the three spokes are then fed through the disc and wheel and secured to the centre boss, this assembly now being a tight fit on the wheel. The outer disc is then secured by the centre stud, and is designed to be easily removable in order to access the tyre valve.