On Fri, 25 Jan 2019 09:34:50 -0000, NY wrote:

"Commander Kinsey" wrote in message
news
I knew steering played a big part (I thought about 50%) because I've seen
a trick played where people are given bicycles with fixed steering, and
it's very difficult to balance on them.

Also there have been tests where a perfectly balanced human-size/weight
dummy is attached to a bike, and it falls over even when it is travelling at
a speed that a human could ride easily. That suggests that minute
adjustments to balance and steering are a major factor in staying upright.

I'm sure the wheels play a big part too - if you remove a bicycle wheel
and keep the hub, then spin it holding the wheelnuts, it's difficult to
turn over. Mind you, maybe that's not enough to prevent the weight of the
rider falling over too.

That's the gyroscopic effect. If the wheel is rotating and you twist the
axle side-to-side (in a horizontal plane), there is a force that tries to
twist the axle up-and-down (in a vertical plane). It acts so as to correct a
tendency to fall over: if you start to lean to the left and the front axle
turns to the left, the gyroscopic force acts to try to move the bike back to
vertical, and its magnitude varies with speed.

I can see why people though that this was the only force that mattered,
since it does play a small part in keeping balance - it's just that it's not
enough on it own.

I would have said a large part. Just try balancing on a bicycle that's stationary.

I read of an experiment where a bike was fitted with wheels that had discs
of equal mass to the wheel that were rotated (electrically) in the opposite
direction so as to cancel out any gyroscopic force. And the bike was still
rideable, though it was slightly harder to keep one's balance.

I guess it's also harder if you have a very lightweight racing bike with lighter wheels. Mind you, I could never ride a bike with narrow handlebars, I can only ride mountain bikes. Not enough leverage to balance by steering in those drop handlebar types.

On Fri, 25 Jan 2019 09:34:50 -0000, NY wrote:

"Commander Kinsey" wrote in message
news
I knew steering played a big part (I thought about 50%) because I've seen
a trick played where people are given bicycles with fixed steering, and
it's very difficult to balance on them.

Also there have been tests where a perfectly balanced human-size/weight
dummy is attached to a bike, and it falls over even when it is travelling at
a speed that a human could ride easily. That suggests that minute
adjustments to balance and steering are a major factor in staying upright.


I'm sure the wheels play a big part too - if you remove a bicycle wheel
and keep the hub, then spin it holding the wheelnuts, it's difficult to
turn over. Mind you, maybe that's not enough to prevent the weight of the
rider falling over too.

That's the gyroscopic effect. If the wheel is rotating and you twist the
axle side-to-side (in a horizontal plane), there is a force that tries to
twist the axle up-and-down (in a vertical plane). It acts so as to correct a
tendency to fall over: if you start to lean to the left and the front axle
turns to the left, the gyroscopic force acts to try to move the bike back to
vertical, and its magnitude varies with speed.

There's something you can do with a computer chair (as in one that can rotate) and a bicycle wheel. I can't remember what it was, something like your friend gets the wheel spinning and hands it to you, then you turn it to the horizontal, making the chair spin round.

I can see why people though that this was the only force that mattered,
since it does play a small part in keeping balance - it's just that it's not
enough on it own.

I read of an experiment where a bike was fitted with wheels that had discs
of equal mass to the wheel that were rotated (electrically) in the opposite
direction so as to cancel out any gyroscopic force. And the bike was still
rideable, though it was slightly harder to keep one's balance.

On Fri, 25 Jan 2019 12:20:34 -0000, whisky-dave wrote:

On Thursday, 24 January 2019 20:47:35 UTC, Romera Etafodor wrote:
On 1/24/2019 3:07 PM, Commander Kinsey wrote:
I tried one, once, I couldn't stay on it. I see countless Youtube videos of people falling off them. But why? If you are about to fall over backwards, shouldn't it feel the tilt of your feet and simply roll under your centre of gravity? It should
be impossible to fall off.


Half the people on the planet are below average IQ so are incapable of riding a self balancing scooter.

I doubt it's anything to do with inteligence, I'd say it's far more likely to do with the way the inner ear affects balance.

Plus reaction speed. I can't balance on a scooter, I also can't hit a tennis ball before it's passed me. But strangely I can react twice as fast as the average person to a simple stimulus where I have to press a button etc. I guess some reactions require a calculation, and that part of me is slower.

For the double-digit IQ crowd there is the Teknique HD6 powered wheelchair.

https://www.hoveround.com/mobility-s...y/teknique-hd6 .

You mean like stephen hawking ?

That wheelchair is more for double digit tonnage - holy ****, 600 pounds! Americans I presume. Although "tandem rear tires for increased traction" doesn't make sense, as judging by the grips on the front tyres, it's front wheel drive.

Have you seen those dumb ****ers on quad bikes killing themselves.

You been watching failarmy?