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The author lost all credibility when he said I have to countersteer to turn my bike. The author is a "professional engineer and consultant, specializing in feed

The author lost all credibility when he said I have to countersteer to turn my bike. The author is a "professional engineer and consultant, specializing in feedback systems and motors" too. There are >50 million cyclists in the US who would presumably immediately recognize this as a false statement and he didn't ask a single one of them to proofread. Edit since some people are confused by this apparently: You can steer your bike away from the edge of a cliff by leaning to initiate the turn instead of countersteering. This makes the author's advice of "Don’t ride your bicycle on the edge of a cliff" much less critical.

jbay808 4y ago
In the interest of defending my credibility, consider the challenge of explaining some concept to an audience using concrete examples, when any example has subtle associated details and exceptions that, while fun to explore on their own, do not further the goal of explaining the original concept. If you'd prefer, I can explain the concept of the right-half-plane zero using only abstract systems described by transfer functions. But I suspect that will be less effective from an education standpoint. I maintain that countersteering a bicycle is an excellent example of a RHP0, and it's no coincidence that a translating inverted pendulum also has an RHP0 in its control solution. I also am one of those cyclists and, at least prior to the pandemic, commuted by bicycle every day.
mk12 4y ago
I'm curious how you're so confident about this. I think if you ask most people (even most cyclists) what happens when you turn the handlebars to the right, they'd say you turn to the right. I cycle almost every day and I thought this for a long time. Have you actually tried it? When I tried it, I found that it forces me into a left turn.
- whycombinetor 4y ago
  Have you tried leaning to the left while biking in a straight line? It results in you turning left without your front wheel ever having gone to the right (i.e., turning without countersteer).
  - kazinator 4y ago
    > Have you tried leaning to the left while biking in a straight line? That is impossible. If you lean your body left while biking in a straight line, the bike will lean right to keep your center of gravity above the track. For bike and body to be leaning left, the bike must already be in a turn. Or else, it must be in the middle of a fall. Two-track vehicles always begin a turn with a countersteering move which induces a fall in the opposite direction. Then the steering immediately switches in the falling direction, to convert the fall into a turn. (In the absence of wind anyway. A left turn could plausibly start without a countersteer if a gust of wind blows over the bike into a left lean; the subsequent left steer and turn will supply the compensating acceleration to prevent a fall.) A bicycle is always countersteering. A bicycle whose steering column is locked out, prevented from turning, cannot be ridden. It will fall over. A bicycle doesn't require a rider in order to maintain balance, either. Above a certain speed, a bicycle can correct itself. This is due to countersteering. Whenever the bicycle accidentally steers slightly to the right, it begins to fall to the left, and this provokes a left steer which prevents a fall. A rider who doesn't understand countersteering nevertheless intuitively "bootstraps" the turn out of these small wobbles, gradually increasing the tilt and and degree of turn, through a sequence of small counter-steering maneuvers.
adiM 4y ago
One can always test the hypothesis via an experiment: https://youtu.be/9cNmUNHSBac https://youtu.be/9cNmUNHSBac
- dilyevsky 4y ago
  Heh was about to reply with the same video. It’s really counterintuitive even for people who ride a lot
  - CamperBob2 4y ago
    It's counterintuitive to cyclists because we don't countersteer. We lean instead, generally subconsciously. If we didn't lean, it's true that we'd have to countersteer... but nobody rides that way, making it a flawed analogy at best.
    - dilyevsky 4y ago
      I’m not good downhill mtb rider but my understanding it’s really common technique there. Even on road i do that not to take a spill in sharp-ish downhill turn going at speed
    - kazinator 4y ago
      You always countersteer; you're just not doing it consciously. Because of that, you're doing it very slightly. Because you're doing it slightly, you enter into turns slowly. You're not able to take sharp corners at a decent speed. You cannot lean without countersteering first; the lean happens because you induced a fall in the desired direction, through a tiny countersteering move. With the tiny, subconscious counter-steers, you induce only small tilts. I suspect it takes multiple small counter-steering maneuvers to "build up" a decent tilt for a sharp turn, which takes time. Once I learned to deliberately countersteer, I then started doing it all the time. I hardly take any turn (big or small) on a bicycle without pushing forward the handle-bar on that side. If you don't make deliberate countersteering your main steering method, so that it becomes second nature, you will not be able to count on yourself to use it in an emergency.

jbay808 4y ago

In the interest of defending my credibility, consider the challenge of explaining some concept to an audience using concrete examples, when any example has subtle associated details and exceptions that, while fun to explore on their own, do not further the goal of explaining the original concept. If you'd prefer, I can explain the concept of the right-half-plane zero using only abstract systems described by transfer functions. But I suspect that will be less effective from an education standpoint. I maintain that countersteering a bicycle is an excellent example of a RHP0, and it's no coincidence that a translating inverted pendulum also has an RHP0 in its control solution. I also am one of those cyclists and, at least prior to the pandemic, commuted by bicycle every day.

mk12 4y ago

I'm curious how you're so confident about this. I think if you ask most people (even most cyclists) what happens when you turn the handlebars to the right, they'd say you turn to the right. I cycle almost every day and I thought this for a long time. Have you actually tried it? When I tried it, I found that it forces me into a left turn.

whycombinetor 4y ago
Have you tried leaning to the left while biking in a straight line? It results in you turning left without your front wheel ever having gone to the right (i.e., turning without countersteer).
- kazinator 4y ago
  > Have you tried leaning to the left while biking in a straight line? That is impossible. If you lean your body left while biking in a straight line, the bike will lean right to keep your center of gravity above the track. For bike and body to be leaning left, the bike must already be in a turn. Or else, it must be in the middle of a fall. Two-track vehicles always begin a turn with a countersteering move which induces a fall in the opposite direction. Then the steering immediately switches in the falling direction, to convert the fall into a turn. (In the absence of wind anyway. A left turn could plausibly start without a countersteer if a gust of wind blows over the bike into a left lean; the subsequent left steer and turn will supply the compensating acceleration to prevent a fall.) A bicycle is always countersteering. A bicycle whose steering column is locked out, prevented from turning, cannot be ridden. It will fall over. A bicycle doesn't require a rider in order to maintain balance, either. Above a certain speed, a bicycle can correct itself. This is due to countersteering. Whenever the bicycle accidentally steers slightly to the right, it begins to fall to the left, and this provokes a left steer which prevents a fall. A rider who doesn't understand countersteering nevertheless intuitively "bootstraps" the turn out of these small wobbles, gradually increasing the tilt and and degree of turn, through a sequence of small counter-steering maneuvers.

adiM 4y ago

One can always test the hypothesis via an experiment: https://youtu.be/9cNmUNHSBac https://youtu.be/9cNmUNHSBac

dilyevsky 4y ago
Heh was about to reply with the same video. It’s really counterintuitive even for people who ride a lot
- CamperBob2 4y ago
  It's counterintuitive to cyclists because we don't countersteer. We lean instead, generally subconsciously. If we didn't lean, it's true that we'd have to countersteer... but nobody rides that way, making it a flawed analogy at best.
  - dilyevsky 4y ago
    I’m not good downhill mtb rider but my understanding it’s really common technique there. Even on road i do that not to take a spill in sharp-ish downhill turn going at speed
  - kazinator 4y ago
    You always countersteer; you're just not doing it consciously. Because of that, you're doing it very slightly. Because you're doing it slightly, you enter into turns slowly. You're not able to take sharp corners at a decent speed. You cannot lean without countersteering first; the lean happens because you induced a fall in the desired direction, through a tiny countersteering move. With the tiny, subconscious counter-steers, you induce only small tilts. I suspect it takes multiple small counter-steering maneuvers to "build up" a decent tilt for a sharp turn, which takes time. Once I learned to deliberately countersteer, I then started doing it all the time. I hardly take any turn (big or small) on a bicycle without pushing forward the handle-bar on that side. If you don't make deliberate countersteering your main steering method, so that it becomes second nature, you will not be able to count on yourself to use it in an emergency.