How do you know? Are you seriously telling me that if you submerged a heavier-than-water wheel by 1/3 of its diameter and then started it spinning quickly that you think the wheel would rise to the surface? I find that hard to believe, since, as I already mentioned in this thread, wheels are round, so the back pushes down even if the front pushes up. Note also that air can be considered to be a fluid, albeit with a lower viscosity than water. So, would you claim that a powered wheel can climb into the air? Heck, why build airplanes? Just put some windscoops onto the wheels of our cars and we can fly away!