Originally Posted by
beelz
Imagine a really low recumbent trike. Then add a second deck to it, but only high enough to clear the lower rider's leg rotation. Would that need to be any higher than maybe 4 feet high? That's not that high, is it?
Remember it's a trike, not a bike...
also maybe with smaller wheels it can get lower.
A trike is much worse for a vertical tandem than a 2 wheeled bent. A high two wheeled bent can lean in corners where a vertical tandem trike will just fall over.
This is why 2 wheeled "tall bikes" like the one pictured above are ridable.