What keeps a bike upright?
 

https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

What keeps a bike upright?
 

On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

What keeps a bike upright?
 

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions. Any bicycle I've ever seen with the front fork in it's proper position soon falls over after being pushed without a rider on it. I also think that the gyroscoptic force of rotating bicycle wheels keeping the bicycle upright is miniscule unless the wheels are turning at very high revolutions. I once saw a video on You Tube of a normal bike with the front fork reversed, and without a rider, that went quite a distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

What keeps a bike upright?
 

On Fri, 4 Jan 2019 12:28:50 -0500, Frank Krygowski
wrote:

On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??


Well, Tom is a little slow on the uptake.

cheers,

John B.

What keeps a bike upright?
 

On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

What keeps a bike upright?
 

On Friday, January 4, 2019 at 3:41:22 PM UTC-8, John B. Slocomb wrote:
On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

All you have to do is look at a Penny Farthing which had totally different geometry but not only was ridable but they raced them. That gives you some idea of just how odd a bicycle really is.

What keeps a bike upright?
 

On 1/5/2019 1:29 PM, wrote:
On Friday, January 4, 2019 at 3:41:22 PM UTC-8, John B. Slocomb wrote:
On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

All you have to do is look at a Penny Farthing which had totally different geometry but not only was ridable but they raced them. That gives you some idea of just how odd a bicycle really is.

It's actually hard to build a bicycle that is not rideable. There's a
somewhat well-known but quirky physics paper out there documenting a
physicists quest to build an unrideable bike. As I recall, he tried
several weird front end geometries, including doing away with trail
entirely. He mounted a second front wheel next to the original and just
above contact with the ground, which he rotated in the opposite
direction to cancel any gyroscopic effects. As I recall, he could ride
anything he built.

But back in the early and most experimental days of modern recumbents
(probably the 1970s) I read about a guy who tried to build a
rear-steering recumbent, based on the idea that it would simplify a
front wheel drive train. IIRC, that was almost impossible to ride.

The variety of current bikes is pretty amazing - long and short
wheelbase recumbents, small wheel folding bikes, kids bikes with
questionable geometries, tandems, box bikes, tall bikes, long-tail cargo
bikes. People ride them all. Handling on some can be a bit quirky,
especially at first, but people adapt.

And that's one of the main things about human beings: We're very adaptable.


--
- Frank Krygowski

What keeps a bike upright?
 

On Sat, 5 Jan 2019 10:29:06 -0800 (PST), wrote:

On Friday, January 4, 2019 at 3:41:22 PM UTC-8, John B. Slocomb wrote:
On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

All you have to do is look at a Penny Farthing which had totally different geometry but not only was ridable but they raced them. That gives you some idea of just how odd a bicycle really is.

Ridable? A bloke rode one across the U.S. in 1884.... and today people
brag when they ride down a gravel road.

There was a discussion here about riding wheelers some time ago and
Frank, I believe, described riding one and apparently they are easier
to balance then the more modern bicycles.

cheers,

John B.

What keeps a bike upright?
 

John B. Slocomb wrote:
On Sat, 5 Jan 2019 10:29:06 -0800 (PST), wrote:

On Friday, January 4, 2019 at 3:41:22 PM UTC-8, John B. Slocomb wrote:
On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they
were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might
end up being extremely difficult to ride. Look at how even small
changes in frame/trail geometry on a road bike creates quite different
handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

All you have to do is look at a Penny Farthing which had totally
different geometry but not only was ridable but they raced them. That
gives you some idea of just how odd a bicycle really is.

Ridable? A bloke rode one across the U.S. in 1884.... and today people
brag when they ride down a gravel road.

There was a discussion here about riding wheelers some time ago and
Frank, I believe, described riding one and apparently they are easier
to balance then the more modern bicycles.

cheers,

John B.

Hard braking, coasting down steep hills and mounting/dismounting
disregarded, of course :-)

What keeps a bike upright?
 

On Sun, 06 Jan 2019 06:05:35 +0700, John B. Slocomb
wrote:

On Sat, 5 Jan 2019 10:29:06 -0800 (PST), wrote:

On Friday, January 4, 2019 at 3:41:22 PM UTC-8, John B. Slocomb wrote:
On Fri, 4 Jan 2019 10:43:12 -0800 (PST), Sir Ridesalot
wrote:

On Friday, January 4, 2019 at 12:28:54 PM UTC-5, Frank Krygowski wrote:
On 1/4/2019 11:37 AM, wrote:
https://www.nature.com/news/the-bicy...matics-1.20281

Of course this isn't for John or Frank who could fall down if they were sitting on the ground.

You're just reading that now??

--
- Frank Krygowski

Seems to me that the guy has made a few basic false assumptions.
Any bicycle I've ever seen with the front fork in it's proper position
soon falls over after being pushed without a rider on it. I also think
that the gyroscopic force of rotating bicycle wheels keeping the
bicycle upright is miniscule unless the wheels are turning at very
high revolutions. I once saw a video on You Tube of a normal bike
with the front fork reversed, and without a rider, that went quite a
distance when pushed before toppling over.

I think too that making a bicycle stable enough to be riderless might end up being extremely difficult to ride. Look at how even small changes in frame/trail geometry on a road bike creates quite different handling characteristics.

Cheers

There has been a lot of research into what makes a bike stable. One
paper I read described a bike that was built with a front fork that
allowed the trail to be adjusted from a negative number to a rather
large positive number and yes "trail" has a great effect on the (would
one say) the longitudinal stability of a bike - how easily the fork
turns, and during the same experiment it was "discovered" that BB
height, vertical location of center of gravity, also effected this
same stability. Bikes have also been built with counter rotating
wheels which counter act the gyroscopic effect of the spinning wheels.

My own guess is that bicycles require stability in at least two planes
and so far no one seems to have built a bicycle that is completely
stable.

cheers,

John B.

All you have to do is look at a Penny Farthing which had totally different geometry but not only was ridable but they raced them. That gives you some idea of just how odd a bicycle really is.

Ridable? A bloke rode one across the U.S. in 1884.... and today people
brag when they ride down a gravel road.

There was a discussion here about riding wheelers some time ago and
Frank, I believe, described riding one and apparently they are easier
to balance then the more modern bicycles.

cheers,

John B.

Correction. should have read "riding high wheelers".

cheers,

John B.