I could not open the link you provided, as it gave me a security message.Can a wheelie bar and wheel, both front and back be fashioned then either powered by pedal or engine you stay upright?
Other:
http://motorbicycling.com/picture.php?albumid=469&pictureid=9274
Was wondering what kind of engine is this on a bike from your album?
MT
I do not know which bike you speak of?