Keith and Sue in PG

Keith and Sue;
Great question and I had same concern. I could detect no towing issue with 2, 50 pound bikes on the bike rack. The Airstream bike rack cannot be installed without the bumper. The bumper and bumper frame weighs less than 50 pounds(bumper is aluminum) and mount frame is steel. The bike rack is 20 pounds +/- a little.
Towing bikes on the Bambi is a treat. It probably lightens the tongue weight some, so you might want to put some weight in the front of the Bambi to increase the tongue weight if you feel it necessary.
By the way, the bike rack is open in the center and the storage boxes slide right through without having to even tilt them. The bumper also acts as a shelf for these.
I also love my Bambi and just loved it more the longer I owned it. Several grand children(and parents) just moved to where I live and I now have unexpected guests and needed a bigger Airstream which I now have. Actually own two and can have my own caravan.
CHad

Keith:
I had same thoughts about weights and balance. The bumper weighs 40 or so pounds with frame. The rack is attached to the bumper and the trailer so the weight distribution is excellent. The tongue weight was not effected and the unit tows without a sway without weight distribution hitch.
The storage containers inside the back easily fit through the rack which I was also concerned about.
Absolutely a perfect addition to a Bambi.
CHad