Not if you keep it level enough, which should be feasible on a four-wheeler. I mean, the gyrobus shows that it's not a infeasible concept - they still let peopl

Not if you keep it level enough, which should be feasible on a four-wheeler. I mean, the gyrobus shows that it's not a infeasible concept - they still let people ride it sometimes here in Antwerp, as a curiosity: http://en.wikipedia.org/wiki/Gyrobus http://en.wikipedia.org/wiki/Gyrobus