Originally Posted by Eatadonut
That just plain doesn't work. Merely leaning your body doesn't turn the bike, otherwise I wouldn't be able to do a rolling mount in a straight line. Either the bike has to lean, "curving" the surface of the wheel and causing the bike to turn, or the wheel has to turn.
They might have more traction when vertical, but they have no turning ability.
To be fair, it does work when on a motorbike. Not on a roadie though! Even then, though, there needs to be a degree of angle from the bike otherwise you're just riding straight but at an angle to the road other than perpendicular!