Comment by nwatson 4 days ago
The gyroscopic effect contributes little to maintaining a balanced bike ride, contrary to the article claim. An idealized massless wheel/tire wouldn't diminish ridability.
Steering dynamics (steering to counteract bike lean) and trail effect (bike are built to automatically counteract lean), along with rider input (steering, leaning body), are more important components.
It's the combination of steering and forward momentum the gives the negative feedback. Bike tips left -> steering turns left -> circular path -> (from moving frame of reference) centrifugal force tips the bike back upright.
Without forward movement you miss the centrifugal force that tips the bike back up.
It is primarily the forward sweep/caster of the front wheel forks which makes the wheel turn into any lean and the forward motion of the bike with the turned wheel tries to bring the bike back under the overall balance point. With the steering axis/forks in a perfectly vertical position where the wheel's contact point and steering axis are perfectly aligned, the wheel will not really respond to leans and you would have to actively turn it to balance. And with a negative caster the wheel would want to actively turn away from any leans making the bike fight against balancing.
While the bike is stationary there's limited options for moving the bike relative to your body. While the bike is moving, you can make small steering adjustments which move the bike left or right relative to your body, which helps re-balance the body-bike stack. The faster forward you're moving, the faster these steering adjustments take effect.
It's easier if you can find a sliiiight incline to do it against. So for instance if the road slopes a bit to the right (more elevated on the left side), I turn my front wheel to the left, "up" the small incline. Then I can push the pedal to go a cm forward, or release it a bit to roll a cm backwards. So it kinda simulates a unicycle, except you use the slight incline to do the backpedaling you would do on a unicycle. The better you get at it, the flatter you can go, and when you find the balance you can lift your hands. Good luck!
Here's me doing it: https://gopro.com/v/QoMmEVLp7pJyX
Once you see how a trackstand is done it breaks the gyroscopic myth immediately.
The easiest bike to trackstand is a fixed gear, you turn the front wheel about 45 degrees to one direction or the other, then find the balance point, with the cranks leveled out. Pedaling forward leans you one way, pedaling backwards leans you the other way.
The next difficulty step is a conventional bike, if you have a slope to point your wheel up, that replaces the ability to pedal backwards.
The final difficulty level is replacing the slope with just brake modulation and body weight.