Comment by beardyw
4 days ago
> Bicycles achieve balance through the gyroscopic effect
No they don't. If that were true you could cycle along at a 45 degree angle. They balance because you steer into a fall.
4 days ago
> Bicycles achieve balance through the gyroscopic effect
No they don't. If that were true you could cycle along at a 45 degree angle. They balance because you steer into a fall.
> They balance because you steer into a fall.
They naturally steer themselves into a fall really.
Wouldn't that imply that a bicycle wheel I roll down the street by itself should fall over immediately which clearly is not the case?
There's not zero gyroscopic force, just negligible compared to the moment of inertia (with the tyre/ground interface as the axis of rotation) of the bike/rider system.
Furthermore you will notice a bicycle wheel rolling down the street often won't roll in a straight line (as it starts to tilt sideways, it will turn to bring the contact patch back underneath it), so even with just the wheel, the gyroscopic stabilization is insufficient on its own to keep it upright.
No that's not true. A bike just naturally steers into its fall.
Veritasium made a video about it: https://youtu.be/9cNmUNHSBac?si=8cbWXgoqg-uuVidb
A bicycle is not the same as a bicycle wheel though. I can't just roll down a bike down the street (at least not as easily as a single wheel); it almost always immediately falls over.
Sure you can.
At very low speeds, yes, the bike will fall over. But a bike with some minimum amount of speed can roll upright on its own just fine. You can try it yourself with your least favorite bike and an empty parking lot. All it takes is a good solid push. It has to do with bicycle frame geometry and center of mass.
Neil deGrasse Tyson explains it in this video at 2:52: https://www.youtube.com/watch?v=RIrgwWQqqts
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It boggles the mind how much people believe gyroscopic forces are what keep bicycles and motorcycles upright. It's even taught in text books.
It only really enters the picture during wheelies, if you've got the front wheel spinning fast enough.