Yakima, Saris, Kuat, RakAttach all make swing away hitches for bike racks. Thule also made them but it looks like they have been discontinued. Each company has different fitment measurements but all will only accept 2” racks. These swing away hitches are rated ~ 200-250 lbs. capacity.
Our Transit has an Aluminess rear bumper with a spare tire and a box on swing out arms. I’m checking out the fitment of the Saris hitch at a local bike shop on Friday to see if that adapter will work for us. The bonus of the RakAttach is that they can be ordered for driver or passenger sides (in large, medium and small sizes). The large size will support e-bikes. I tried using the front bumper for a bike rack to avoid purchasing a swing away, but it was a “no go” from a driver visibility safety issue … bummer.
I have reached out to RakAttach to see if they will accommodate an Aluminess bumper. Here is the fitment dimensions from RakAttach.com