The opening of the video describes the difficulty (impossibility?) of balancing a bike with the handlebars locked.
I've had frustrating arguments with engineers on the degree to which the gyroscopic effect of the bicycle wheels are what keep the bike upright. They seemed to think it's the spinning wheels that allow you to balance. (I suppose in their minds this would explain why it is difficult to balance when rolling very slowly.)
Give the bike a brisk shove, I argue, with no one on it and see how far it balances. In my experience, a bicycle balances for about as long as it takes to fall over.
I see the rider+bike as an inverted pendulum ... or like someone balancing an inverted broom on the tip of their finger if you will. Steering is the rather counter-intuitive means by which one moves the contact point with the ground left and right under the larger mass (the rider) to balance it.
Maybe the opening to the video or the Arduino-controlled contraption (lacking gyroscopic wheels) will get more people to re-think this.
> 've had frustrating arguments with engineers on the degree to which the gyroscopic effect of the bicycle wheels are what keep the bike upright. They seemed to think it's the spinning wheels that allow you to balance.
Hmm, why there is even arguing about rhat, given that there is even technique that every even advanced amateur knows: trackstand https://youtu.be/-0VnQJF_WKQ
Balancing is hardly anything to do with the gyroscopic effect of wheels. You balance by steering the bike under the centre of gravity. Veritasium : https://youtu.be/9cNmUNHSBac
Gyroscopic wheels allow you to have some time to balance, so you won't fall instantly but have few seconds to move your center of gravity. Try to balance on a bicycle which does not move. While it might be possible for experienced acrobat, it's much harder.
But when the bicycle is not moving, lost too is the ability to move your point of balance through steering. That alone explains how hard it is to balance when not moving.
I do not believe the wheels spinning give you even a modest assistance in balancing.
It does seem possible for some bicycles to roll quite far without a rider before falling over. I suspect there's some sort of natural feedback mechanism related to the angle of the front fork and the positioning of the wheels with respect to the axis the handlebars rotate on.
I also suspect this is related to the fact that some bicycles are clearly easier to ride without touching the handlebars than others.
I agree that the gyroscopic effect is minimal at low speeds. Bicycle design may take it into account somewhat at high speeds, but clearly people can ride bicycles at low speeds with small wheels where the impact of the gyroscopic effect would be minimal.
Consider the case of a Razor scooter. I seriously doubt 4-inch Wheels have any significant gyroscopic effect on the ride.
Essentially, a bicycle is an inverted pendulum and the fork acts as a feedback mechanism. The fork geometry (caster angle) translates lateral force at the front wheel into steering inputs. Gyroscopic forces also contribute. These effects all act more strongly at higher speed.
The fork must be free to move, or the feedback won't work.
Bicycle stability is well studied. As long as the bicycle continues to travel above the critical speed and on a flat surface without obstruction, it will remain upright given it was constructed of a stable design.
I've had frustrating arguments with engineers on the degree to which the gyroscopic effect of the bicycle wheels are what keep the bike upright. They seemed to think it's the spinning wheels that allow you to balance. (I suppose in their minds this would explain why it is difficult to balance when rolling very slowly.)
Give the bike a brisk shove, I argue, with no one on it and see how far it balances. In my experience, a bicycle balances for about as long as it takes to fall over.
I see the rider+bike as an inverted pendulum ... or like someone balancing an inverted broom on the tip of their finger if you will. Steering is the rather counter-intuitive means by which one moves the contact point with the ground left and right under the larger mass (the rider) to balance it.
Maybe the opening to the video or the Arduino-controlled contraption (lacking gyroscopic wheels) will get more people to re-think this.