| MadSci Network: Physics |
As you say, the small wheels on the scooter provide only a small amount of gyroscopic action that aids to keep the scooter balanced. The major reason you can balance it when it's in motion is that extremely small steering changes can provide quite a lot of balancing correction. For instance, if the scooter is starting to lean to the left, your body senses that and you instinctively (after some practice, at least) make a minor change in direction toward the left. In doing so, the original momentum of the scooter now points slightly to the right of the new direction, which tends to put the scooter back up where you want it.
I have no idea what percentage of balancing is provided by the wheels and how much is provided by the active direction corrections.
John Link, MadSci Physicist
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