so how do bicycles work ...

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Jules59
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so how do bicycles work ...

Post by Jules59 »

AndyK
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Re: so how do bicycles work ...

Post by AndyK »

Good spot. That's an excellent video with clear demonstrations and explanations of the physics involved in steering a bike - and why you can't even ride a bike if you can't steer it - all packed into 11 entertaining minutes. Highly recommended.
scottg
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Re: so how do bicycles work ...

Post by scottg »

If you get a chance try riding a racing trike aka barrow.
They work opposite a regular bike, very entertaining and educational.
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Jules59
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Re: so how do bicycles work ...

Post by Jules59 »

rogerzilla
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Re: so how do bicycles work ...

Post by rogerzilla »

A bike will ride itself*, at least in a straight line. It needs no help from you. As long as the steering moves freely enough, it self-corrects as it starts to topple. It's an astonishing invention, really.

*you can easily prove this by pushing it downhill, but it's best to do it with soneone else's bike
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Mick F
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Re: so how do bicycles work ...

Post by Mick F »

It's true that a bike will steer itself. No argument from me.

Trouble is, when you put a person on it, the centre of gravity changes and it's not as simple any more. Some frame geometries are more stable than others.
Mick F. Cornwall
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531colin
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Re: so how do bicycles work ...

Post by 531colin »

rogerzilla wrote: 1 Dec 2021, 7:05am A bike will ride itself*, at least in a straight line. It needs no help from you. As long as the steering moves freely enough, it self-corrects as it starts to topple. It's an astonishing invention, really.

*you can easily prove this by pushing it downhill, but it's best to do it with soneone else's bike
Its an interesting piece of trivia, but has nothing to do with how we actually balance a bike.
(a 30 pound bike can't possibly hold up a 15 stone rider)
Jdsk
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Re: so how do bicycles work ...

Post by Jdsk »

Thanks for posting.

I'd never thought of demonstrating it with that sort of modification. But I've often looked for a recording of steering angle as turns are initiated. You can almost get that from the head-on shots in the video, but a plot would be nice.

Highly Recommended, as always: "Bicycling Science":
https://mitpress.mit.edu/books/bicyclin ... th-edition

Jonathan
Jdsk
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Re: so how do bicycles work ...

Post by Jdsk »

Does anyone deliberately discuss counter-steering when helping people to learn to ride a bike? I don't.

Jonathan
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531colin
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Re: so how do bicycles work ...

Post by 531colin »

I find the whole business of countersteering interesting.
("countersteering" is, I think, the name given to how you turn the handlebars to the left in order to lean the bike to the right to initiate a right turn.)
I have no doubt that countersteering is how I initiate a turn on a motorbike which weighs more than I do.
On a bicycle, when I'm riding "hands on" I may do the same.
When I'm riding a bicycle "no hands" I don't think I can countersteer.
Riding no hands I think what happens is I lean the bike in the direction I want to steer; the handlebars turn in the right direction due to "wheel flop" https://en.wikipedia.org/wiki/Bicycle_a ... e_geometry
I can't think how you might do countersteering "no hands"......To initiate a right turn, I have to countersteer left; but in order to steer left I must lean left, which actually initiates a left turn.
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531colin
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Re: so how do bicycles work ...

Post by 531colin »

Jdsk wrote: 1 Dec 2021, 11:02am Does anyone deliberately discuss counter-steering when helping people to learn to ride a bike? I don't.

Jonathan
Riding a bike is a conditioned reflex, like walking. Thinking about what you are doing is probably unhelpful?
Jdsk
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Re: so how do bicycles work ...

Post by Jdsk »

531colin wrote: 1 Dec 2021, 11:08am
Jdsk wrote: 1 Dec 2021, 11:02am Does anyone deliberately discuss counter-steering when helping people to learn to ride a bike? I don't.
Riding a bike is a conditioned reflex, like walking. Thinking about what you are doing is probably unhelpful?
I actively discuss many of the component skills. And encourage the learner to think about many of the things that they are doing while they're doing them. But not this one... it's complicated and I don't think that it would help. But maybe we should do the experiment... ?

Jonathan
axel_knutt
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Re: so how do bicycles work ...

Post by axel_knutt »

Jdsk wrote: 1 Dec 2021, 11:14am
531colin wrote: 1 Dec 2021, 11:08am
Jdsk wrote: 1 Dec 2021, 11:02am Does anyone deliberately discuss counter-steering when helping people to learn to ride a bike? I don't.
Riding a bike is a conditioned reflex, like walking. Thinking about what you are doing is probably unhelpful?
I actively discuss many of the component skills. And encourage the learner to think about many of the things that they are doing while they're doing them. But not this one... it's complicated and I don't think that it would help. But maybe we should do the experiment... ?

Jonathan
There's a phenomenon known to psychologists whereby attempting to explain a skill that's performed intuitively ruins the teacher's ability to perform that skill. I think there's a famous case of an ace golfer who went from winning everything to losing everything after writing a book about how to do it.
“I'm not upset that you lied to me, I'm upset that from now on I can't believe you.”
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mattheus
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Re: so how do bicycles work ...

Post by mattheus »

axel_knutt wrote: 1 Dec 2021, 11:29am
Jdsk wrote: 1 Dec 2021, 11:14am
531colin wrote: 1 Dec 2021, 11:08am
Riding a bike is a conditioned reflex, like walking. Thinking about what you are doing is probably unhelpful?
I actively discuss many of the component skills. And encourage the learner to think about many of the things that they are doing while they're doing them. But not this one... it's complicated and I don't think that it would help. But maybe we should do the experiment... ?

Jonathan
There's a phenomenon known to psychologists whereby attempting to explain a skill that's performed intuitively ruins the teacher's ability to perform that skill. I think there's a famous case of an ace golfer who went from winning everything to losing everything after writing a book about how to do it.
That makes sense.

I think truly good coaches know how to guide someone to perform a skill well - they don't simply describe what they do, then tell their student to "do that"!

(the opposite is usually true with conscious/cerebral skills - wiring a plug, or long division maybe. TEACHING can make you better at the skill - or sometimes show you that you're not quite the expert you thought you were !)
sjs
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Re: so how do bicycles work ...

Post by sjs »

531colin wrote: 1 Dec 2021, 11:08am
Jdsk wrote: 1 Dec 2021, 11:02am Does anyone deliberately discuss counter-steering when helping people to learn to ride a bike? I don't.

Jonathan
Riding a bike is a conditioned reflex, like walking. Thinking about what you are doing is probably unhelpful?
However it is that I ride a bike, it made me look a complete idiot when I tried to ride a tricycle. You'd think it would be more or less impossible to fall off one, but I'm not so sure.
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