Bruce Gordon Motto "hoopless is Hopeless"
I have Bruce's I added a Braze on for the light on the side of the Hoop
(summer days are long so Its a Battery Light)

The other type needs a Bolt thru the Fork ( or 2 threaded bosses aligned like that )
and the rack doubly braced on each side.


http://www.tubus.com/documents/1442217084_Duo_BM.pdf