YouTube - We Still Don’t Know How Bicycles Work

We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.

--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On 1/23/2021 9:53 PM, Jeff Liebermann wrote:
We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.

Interesting video, although there wasn't much in there I hadn't read
before. I'll look at the sources you cited one of these days.

But it may take a Jules Verne to come up with a practical use for some
of the most recent developments. The Delft team's self-stable "bicycle"
http://bicycle.tudelft.nl/schwab/Bic...imentLarge.jpg
barely looks like a bicycle at all. I gather the high forward mass is a
critical component. It may justify the huge front basket on my teenage
years' paper delivery bike (and my love of handlebar bags), but what
else can you do with that, really?

BTW, the mathematics those guys play with is no longer appealing to me,
if it ever was. I remember having to work with equations so long they
required two or three lines to write them out on a page. I don't do that
any more. I'm retired.

Just a few days ago I got curious about some aspects of fuel consumption
by a car. I worked up some equations and began programming them in my
HP-48 calculator. I had to dig out the calculator manual to remember how
to do that.

--
- Frank Krygowski

On 1/23/2021 9:53 PM, Jeff Liebermann wrote:
We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.

I liked this one:
https://www.cbc.ca/news/technology/s...ious-1.3699012

Especially Papadopoulos's discussion on how little difference weight
makes, and what makes more difference.


--
- Frank Krygowski

On Saturday, January 23, 2021 at 7:45:30 PM UTC-8, Frank Krygowski wrote:
On 1/23/2021 9:53 PM, Jeff Liebermann wrote:
We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.
Interesting video, although there wasn't much in there I hadn't read
before. I'll look at the sources you cited one of these days.

But it may take a Jules Verne to come up with a practical use for some
of the most recent developments. The Delft team's self-stable "bicycle"
http://bicycle.tudelft.nl/schwab/Bic...imentLarge.jpg
barely looks like a bicycle at all. I gather the high forward mass is a
critical component. It may justify the huge front basket on my teenage
years' paper delivery bike (and my love of handlebar bags), but what
else can you do with that, really?

BTW, the mathematics those guys play with is no longer appealing to me,
if it ever was. I remember having to work with equations so long they
required two or three lines to write them out on a page. I don't do that
any more. I'm retired.

Just a few days ago I got curious about some aspects of fuel consumption
by a car. I worked up some equations and began programming them in my
HP-48 calculator. I had to dig out the calculator manual to remember how
to do that.

We know exactly how bicycles work. If you reverse the rake and trail you can't ride the bike without hands. That shows that bicycles work work by self balancing around the gyroscopic effect of the wheels and the rake and trail that was developed over many years of bicycle construction and use.

On Mon, 25 Jan 2021 12:19:05 -0500, Frank Krygowski
wrote:

Especially Papadopoulos's discussion on how little difference weight
makes, and what makes more difference.

I lost a lot of weight when I rode in the September Century every
year, and did a lot of my training west of the eastern cliffs of the
Helderbergs.

I think the main reason I lost weight was that whenever I saw a
tempting goodie, my first thought was "I don't want to haul that up
New Salem Hill".

Even the racing team from RPI had to take a nap halfway up.

The walkways between RPI's buildings were mostly steps, so those guys
were probably in pretty good shape.

--
joy beeson at centurylink dot net
http://wlweather.net/PAGESEW/
The above message is a Usenet post.

On 1/25/2021 1:11 PM, Tom Kunich wrote:
On Saturday, January 23, 2021 at 7:45:30 PM UTC-8, Frank Krygowski wrote:
On 1/23/2021 9:53 PM, Jeff Liebermann wrote:
We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.
Interesting video, although there wasn't much in there I hadn't read
before. I'll look at the sources you cited one of these days.

But it may take a Jules Verne to come up with a practical use for some
of the most recent developments. The Delft team's self-stable "bicycle"
http://bicycle.tudelft.nl/schwab/Bic...imentLarge.jpg
barely looks like a bicycle at all. I gather the high forward mass is a
critical component. It may justify the huge front basket on my teenage
years' paper delivery bike (and my love of handlebar bags), but what
else can you do with that, really?

BTW, the mathematics those guys play with is no longer appealing to me,
if it ever was. I remember having to work with equations so long they
required two or three lines to write them out on a page. I don't do that
any more. I'm retired.

Just a few days ago I got curious about some aspects of fuel consumption
by a car. I worked up some equations and began programming them in my
HP-48 calculator. I had to dig out the calculator manual to remember how
to do that.

We know exactly how bicycles work. If you reverse the rake and trail you can't ride the bike without hands. That shows that bicycles work work by self balancing around the gyroscopic effect of the wheels and the rake and trail that was developed over many years of bicycle construction and use.

You should contact Jim Papadopoulos and Delft University immediately.
They'd love to borrow your amazing expertise.

But a warning: Those guys use math.

--
- Frank Krygowski

On Monday, January 25, 2021 at 10:57:32 AM UTC-8, Frank Krygowski wrote:
On 1/25/2021 1:11 PM, Tom Kunich wrote:
On Saturday, January 23, 2021 at 7:45:30 PM UTC-8, Frank Krygowski wrote:
On 1/23/2021 9:53 PM, Jeff Liebermann wrote:
We Still Don’t Know How Bicycles Work
https://www.youtube.com/watch?v=YWsK6rmsKSI (11:38)

Nothing much on the technical details but the video does summarize the
history of various attempts to understand why the bicycle is so
stable.

Sources used in the video:

Sorrel, Charlie, The Bicycle is Still a Scientific Mystery: Here’s
Why, Fast Company, August 1, 2016,
https://www.fastcompany.com/3062239/the-bicycle-is-still-a-scientific-mystery-heres-why

Borrell, Brendan, The Bicycle Problem that Nearly Broke Mathematics,
Nature, July 20, 2016,
https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/

Kachur, Torah, Science of Cycling Still Largely Mysterious, CBC News,
July 28, 2016,
https://www.cbc.ca/news/technology/science-of-cycling-still-mysterious-1.3699012

Cartwright, Jon, How to Keep a Riderless Bike from Crashing, Science,
April 14, 2011,
https://www.sciencemag.org/news/2011/04/how-keep-riderless-bike-crashing

Busca, Nick, Your Bike’s Secret to Staying Upright is Actually a
Mystery, Bike Radar, October 19, 2016,
https://www.bikeradar.com/features/your-bikes-secret-to-staying-upright-is-actually-a-mystery/

My apologies for this being on topic and for not including anything on
politics, law, civics, COVID-19, bouncing tomatoes, chainsaws,
ethanol, bearings, etc. If you can't be part of the solution, being
part of the problem can also be fun.
Interesting video, although there wasn't much in there I hadn't read
before. I'll look at the sources you cited one of these days.

But it may take a Jules Verne to come up with a practical use for some
of the most recent developments. The Delft team's self-stable "bicycle"
http://bicycle.tudelft.nl/schwab/Bic...imentLarge.jpg
barely looks like a bicycle at all. I gather the high forward mass is a
critical component. It may justify the huge front basket on my teenage
years' paper delivery bike (and my love of handlebar bags), but what
else can you do with that, really?

BTW, the mathematics those guys play with is no longer appealing to me,
if it ever was. I remember having to work with equations so long they
required two or three lines to write them out on a page. I don't do that
any more. I'm retired.

Just a few days ago I got curious about some aspects of fuel consumption
by a car. I worked up some equations and began programming them in my
HP-48 calculator. I had to dig out the calculator manual to remember how
to do that.

We know exactly how bicycles work. If you reverse the rake and trail you can't ride the bike without hands. That shows that bicycles work work by self balancing around the gyroscopic effect of the wheels and the rake and trail that was developed over many years of bicycle construction and use.
You should contact Jim Papadopoulos and Delft University immediately.
They'd love to borrow your amazing expertise.

But a warning: Those guys use math.
Why don't you tell us about that math that can measure the circumference of a oval?

On Monday, January 25, 2021 at 3:44:02 PM UTC-6, wrote:

Why don't you tell us about that math that can measure the circumference of an oval?
Google is your friend: the formula is PI * SquareRoot of 2 * ((1/2 long axis)squared + (1/2 short axis)squared).
Or even easier: http://www.csgnetwork.com/circumelli...0axis)squared).

On Mon, 25 Jan 2021 13:44:00 -0800, Tom Kunich scribed:


But a warning: Those guys use math.
Why don't you tell us about that math that can measure the circumference
of a oval?

It is called a TAPE MEASURE. That is what YOU* could use to MEASURE the
circumference of an oval.

Alternative, if you use that search engine skills recommended to you, you
can find plenty of internet pages that tell you how to CALCULATE te
circumference of an oval.

*OTOH, since I studied and completed a course involving land surveying
skills, I could use a modern theodolite to it quicker. Do you want to be
my chainman.

On Mon, 25 Jan 2021 13:44:00 -0800 (PST), Tom Kunich
wrote:

Why don't you tell us about that math that can measure the circumference of a oval?

The reason why I don't tell you about the mathematics of an oval is
that I'm terrible at math. However, that's never stopped me from
trying.

Measure the circumference? That's easy. Take the drawing of the
oval. Run a string around the circumference or perimeter. Where the
ends overlap, cut both strings. Remove string and measure its length
with a ruler, which is the circumference. No math required. Was this
a trick question?

What you probably wanted was how to "calculate" the circumference of
an oval. That's far more difficult because there's no equation that
defines an oval and there are several types of ovals. I can put
together some approximations based on breaking apart the oval into
known geometric sections, such as arcs (partial circles) and straight
lines. However, that's probably not what you want.

Another way works for ovals that are not particularly eccentric (i.e
are fairly circular) and have axial symmetry. The circumference of
such an oval is approximately the circumference of a circle with a
diameter equal to the geometric average diameter of the two included
circles. I just tested a few examples using a circle template. It
works nicely when the two included circle used to construct an oval
are approximately equal diameters, but falls apart rapidly after the
ratio of their diameters is greater than about 2:1.

Another approximation is based on first calculating the area of an
oval:
https://mathworld.wolfram.com/Oval.html
Incidentally, here's easy special cased called a stadium:
https://mathworld.wolfram.com/Stadium.html
First, I calculate the radius of a circle that has the same area as
the oval. I then calculate the circumference of a circle with the
same radius. Again, this works best with a not particularly eccentric
oval.

My turn. You've mentioned that it was impossible to calculate the
circumference of an oval several times in R.B.T. If you knew that it
was impossible, why did you ask Frank for a solution? Could it be you
had some motive other than learning how it might be done?


--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558