Hmm, so most of you don't like the idea of a tail and rear fins?
Here's a first image.
Now it balanced, staying perfectly level.
I admit it has now something of a Ork gyrocopter....
Anyhow, I have to redo the whole thing, as I made a major mistake yesterday (after I took this image), so here's the chance for your vote :-P
So, should my SP-bike have a tail or not?