Very clever. The bike seems to be supported on top of the wheels, not the axles. So the frame does not jump up and down much as the wheels seem to be designed so that the distance from the ground to the top is constant.
The front tire may be a 4 bar linkage, the axle moves foward and back to keep the distance from ground to top constant.
The world needs a video of this thing.
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.