From time to time I come across bicycles with a particular geometry (or rather a lack of). Most of them have no seat and a single tube which simply connects wheels and has the bottom bracket (if that still makes sense) in the middle of it.
Shouldn't the frame split in two by the force put on the "bottom bracket" while pedaling? Is the "bottom bracket" stay strengthened in any way? Does the lack of the seat tube imply there is less load on the frame? I assumed that the "diamond" shape of a bicycle offsets the bending and compressing forces that act on a beam structure.