Yep. No seat tube. You’ll be amazed why: It’s not needed. Yep, it’s that simple. Bicycles are made with that diamond/double-triangle shape because it’s easy and cheap, not because the seat tube holds you up. In fact, most of that structural support comes from the top and down tubes, which made our decision easy. We opted to reduce the amount of material needed to make the frame.
We also opted to make something not so easy and pretty damn cool. (Though maybe not quite as cheap.)