@enobacon
I have the predecessor, the Free Radical (on left). I've read that if the passenger weight is behind the rear axle, then the horizontal beam supporting the rearmost point can buckle at the rear axle.
It looks like the Big Dummy (on right) has something like a "suspension bridge" with a verticle strut from the rear axle, and a "cable" (actually tubing) from the rearmost point, up and over the vertical strut.
I'd like to figure-out how to add something like that to my bike.