Apparently, We Still Don't Know How Bikes Work.

[The Cumbrian]

https://youtu.be/YWsK6rmsKSI

[mikejd]

Amusing and interesting...

Looks like this might be another thing like 'bumblebees theoretically can't fly but they don't know that'

[RobLyon]

Does a gyroscope in the opposite direction actually cancel out the affect or does it just double it?

[jameso]

Haven't watched it yet but if they're talking about gyroscopes they're way off understanding bikes. It's the classic Q.I. type question and qyroscopes always come up as the clever-sounding but wrong answer. You might be suprised by who in the bike design world has come out with it as an answer before too.

We do understand how bikes work, it's just hard to model. There have been some successes with robotics in this area so it must be something that can be reduced to code thf. understood.

[ScotRoutes]

Haven't watched it yet

Here's a clue; watch it

[jameso]

Haven't watched it yet

Here's a clue; watch it

They said gyroscopes weren't the reason I hadn't realised that idea had been disproved as long ago as that as it still comes up as an answer.
"everybody knows how to ride a bike, but nobody now how we ride bikes"
But I'd say we do. It's how they programmed the robot, and he referred a robot riding a bike in the film.
He says it's stumping the leading mathematicians and engineers - I get that. Crazy complex maths to model it and predict outcomes numerically. Way beyond me. But the basic mechanics are not so complex, there's a relationship between steering geo and lean angles and our weight. We ride a bike by leaning that relationship and making continual adjustments to manage the fall to one side or another. We're never in balance, always in motion (the pushed bike shows that same relationship working w/o our input). There's case law based on this after someone demonstrated this principle, which means a cyclist is defendable if a cause of an accident is said to be they steer/'swerved' as they moved forwards, ie that's how we ride bikes.

[ScotRoutes]

And then we un/re-learn steering when we get a bigger and heavier bike. Counter-steering makes a huge difference with a motorbike but I'm not aware of ever having used the technique on a pedal bike (though maybe I'm doing it sub-consciously).

[whitestone]

And then we un/re-learn steering when we get a bigger and heavier bike. Counter-steering makes a huge difference with a motorbike but I'm not aware of ever having used the technique on a pedal bike (though maybe I'm doing it sub-consciously).

I do it on the fat bike, especially on harder surfaces such as roads. It's a subtle movement and more as a result of dropping the outside shoulder than actually turning the bars but there's so much grip on the tyres that even attempting to steer into the turn causes a twitch

[jameso]

And then we un/re-learn steering when we get a bigger and heavier bike. Counter-steering makes a huge difference with a motorbike but I'm not aware of ever having used the technique on a pedal bike (though maybe I'm doing it sub-consciously).

In theory we do it on any bike, though from a point of balance that we're never truly in so it'll not always be needed if our weight is on the side of / direction of the turn already. Perhaps what makes modelling all this so hard is that you can slalom through cones for ex without any real counter steer (or the action is one big counter steer cycle), or you'd use a lot of counter-steer -or do similar with the back wheel for faster riders then me- to corner hard on a DH bike. Just another area where the brain is a more impressive computer than anything we can build?

[Bearbonesnorm]

I tend to believe we counter steer anything with two wheels to some (even small) degree.

I recall once being told by a lecturer, that riding a bike was simply a continuous series of near crashes carried out quickly ... sounds about right.

[Alpinum]

"Cancelling out the gyroscopic effect"

I don't think that when you add another two counter rotating (equal mass, speed etc.) wheels to your bicycle you cancel out he gyroscopic effect.
All four wheel rotate, it doesn't matter in which direction.
To put it differently, a bicycle with two regular wheels and two counter rotaring wheels needs (2 x) more energy to accelerate than the same bicycle with two wheels. Given this, there's 2 x the rotational force to keep it upright. (Friction of bearings, aerodynamic etc. by side).


Would be interesting to find out if the force of bringing the bicycle off line is twice as high, or the bike needs half the speed to be equally stable, when using two additional, equally sized and heavy counter rotating wheels to the regular two of the bike. Should this be the case, it would prove my understanding right.

Until then, I don't believe the counter rotation to cancel out the gyroscopic effect.

?

[ScotRoutes]

https://www.youtube.com/watch?v=vGun5at ... hannel=cgs

[BigdummySteve]

https://m.youtube.com/watch?v=MFzDaBzBlL0

Riding a bike is impossible, everyone knows that

[BigdummySteve]

A huge amount of technical stuff here
https://en.m.wikipedia.org/wiki/Bicycle ... e_dynamics

I remember an article in Performance bikes many years ago discussing the science of turning bikes.
I went out afterwards and actively counter steered my slow turning Honda V4, it was nearly horizontal in the blink of an eye.
I’d avoid reading too much, I think it’s possible that by reading enough your brain might realise it’s impossible and you might never be able to balance again. Let it lie I say

[Alpinum]

https://www.youtube.com/watch?v=vGun5at ... hannel=cgs

Thanks.
Hhmmm... I would like to understand my questioning, but nope... didn't help. I must have a knot in my brain.

But I'm certain that Claire de Lune is a nice composition.
Lamb uses it for Angelika - another nice song.

[fatbikephil]

I'm with Stu - you are constantly making tiny adjustments to keep you upright. Think of riding at sub 1 mph or track standing - this exaggerates the movement required but you are still doing it at speed its just less noticeable. Anything above walking speed and you will be counter steering, you just don't realise it. I'd also say that gyroscopic effect will come in but only at high speeds. A good reason to have very heavy wheels as the bike will be more stable

[Alpinum]

A good reason to have very heavy wheels as the bike will be more stable

Yeah. That's why I ride a penny farthing. Best bike for everything!
Because it's so true...
!!!

Yay!

[Mariner]

A question arising from the initial video of the guy launching a bike across a carpark.
How long would a bike stay upright on driven rollers?
Going out on a limb here but the answer I suspect is as long as it takes to fall over.

I would be looking at momentum/deviation from vertical/c of g sort of equation but perhaps they are asking the wrong question.
Richard Feynman would have this sorted in no time.

[jameso]

How long would a bike stay upright on driven rollers?

Ha.. classic STW thread revisited, something about a plane on a conveyor belt?

I’d avoid reading too much, I think it’s possible that by reading enough your brain might realise it’s impossible and you might never be able to balance again. Let it lie I say

Yup..

[psling]

Well, the good thing about riding a bike is that once you've learned you (apparently) never forget

[BigdummySteve]

Isn’t that elephants?

[psling]

Isn’t that elephants?

Us riding elephants or elephants riding bikes?

[Cheeky Monkey]

The obvious extension to that is elephants riding us but eww (plus "OMFG" and ouch!).

[BigdummySteve]