Bike stability physics

Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...rd.html?page=1

or http://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

On Jul 4, 8:00 am, Frank Krygowski wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.


Yes - *very* interesting. Upon cursory perusal, it would appear to
validate the significance of what a rider "feels".

On Jul 4, 9:00*am, Frank Krygowski wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

wrote:
On Jul 4, 9:00 am, Frank wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...rd.html?page=1

The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.

--Winston

On Jul 4, 10:05 am, Winston wrote:
wrote:
On Jul 4, 9:00 am, Frank wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...-to-the-drawin...

The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.


All very interesting, yes (I must admit I have not spent time studying
this material in depth, and didn't even realize this was a video
["Your System Status - WE'RE SORRY - You need to update you Flash
Player"]), but what about when the bike and rider are leaned over at
speed and both tires are slipping and scrubbing across the ground?
This is a perfectly valid mode of operation. Care to explain how that
works? You guys can't even explain how it works for a little old lady
toodling straight down the lane.

(Understand that I know there is an explanation. I am absolutely
curious about how things work and revel in science and gaining
understanding. It just bugs me when people discount the difficulty
explaining the amazing depth and intricacy of human perception and
ability.)

On Jul 4, 10:50 am, Dan O wrote:
On Jul 4, 10:05 am, Winston wrote:



wrote:
On Jul 4, 9:00 am, Frank wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...-to-the-drawin...

The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.

All very interesting, yes (I must admit I have not spent time studying
this material in depth, and didn't even realize this was a video
["Your System Status - WE'RE SORRY - You need to update you Flash
Player"]), but what about when the bike and rider are leaned over at
speed and both tires are slipping and scrubbing across the ground?
This is a perfectly valid mode of operation. Care to explain how that
works? You guys can't even explain how it works for a little old lady
toodling straight down the lane.

(Understand that I know there is an explanation. I am absolutely
curious about how things work and revel in science and gaining
understanding. It just bugs me when people discount the difficulty
explaining the amazing...

.... almost *magical*...

... depth and intricacy of human perception and
ability.)

On Jul 4, 6:50*pm, Dan O wrote:
On Jul 4, 10:05 am, Winston wrote:



wrote:
On Jul 4, 9:00 am, Frank *wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin....

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke *tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...-to-the-drawin...

The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.

All very interesting, yes (I must admit I have not spent time studying
this material in depth, and didn't even realize this was a video
["Your System Status - WE'RE SORRY - You need to update you Flash
Player"]), but what about when the bike and rider are leaned over at
speed and both tires are slipping and scrubbing across the ground?
This is a perfectly valid mode of operation. *Care to explain how that
works? *You guys can't even explain how it works for a little old lady
toodling straight down the lane.

(Understand that I know there is an explanation. *I am absolutely
curious about how things work and revel in science and gaining
understanding. *It just bugs me when people discount the difficulty
explaining the amazing depth and intricacy of human perception and
ability.)

Bike steering while banked in a corner is due to the leading edge of
the tyre being laterally displaced due to the lean itself, more than
that induced by the rider at the steering pivot, hence what can seem
as as extreme cornering with little steering. The rider's weight is
biased slightly to the rear hence a greater tyre slip angle at the
rear encouraging cornering. The rider's weight between the wheels
hels to flex the frame if ridden off centre, so again encouraging rear
wheel steer.
Managing to get both tyres to scrub significantly and raise the bike
up again usually brings a big smile.
Smiles power all the best steeering setups.
If that doesn't work, get a motorbike and smiles will make speed.

Dan O wrote:
On Jul 4, 10:05 am, wrote:
wrote:
On Jul 4, 9:00 am, Frank wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...-to-the-drawin...

The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.


All very interesting, yes (I must admit I have not spent time studying
this material in depth, and didn't even realize this was a video
["Your System Status - WE'RE SORRY - You need to update you Flash
Player"]), but what about when the bike and rider are leaned over at
speed and both tires are slipping and scrubbing across the ground?

That sounds like a completely different regimen than
the example shown, which is a road bike sans seat
launched straight and riderless across a smooth lot.
I agree with the narrator that the inertia stored
in the rotating wheels and tires also tends to mitigate
against change, too.

One view of the video and you would see what I was
on about. The 'simplified' bicycle in the video
was a puzzler, unless it's four wheels would explain
why it seeked verticality, I wouldn't begin to guess
why it doesn't topple over when perturbed at speed.

This is a perfectly valid mode of operation. Care to explain how that
works? You guys can't even explain how it works for a little old lady
toodling straight down the lane.

Same answer. I'll share a secret with you if you promise
not to reveal it to anyone. My father taught me how to
ride a bike by launching me atop it across a parking lot.
He told me that in order to turn, I merely had to lean.

That was total ******** of course; when I merely leaned,
I fell on to the unforgiving tarmac. I soon learned that
unless I steered into the turn, I would add more
blacktop to my diet. The video shows that the head
angle of the bicycle naturally allows the front wheel
to steer into a turn, if left alone.

By the time I ended my active career on two wheels, I
learned about counter-steering, which is a different
issue. It is criminal that counter-steering is not taught
to every newly - minted motorcycle rider.

But then, where would us old farts get all those nice
healthy hearts and kidneys from?

(Understand that I know there is an explanation. I am absolutely
curious about how things work and revel in science and gaining
understanding. It just bugs me when people discount the difficulty
explaining the amazing depth and intricacy of human perception and
ability.)

Me too!

--Winston

On 7/4/2011 10:57 PM, Winston wrote:
[...]
By the time I ended my active career on two wheels, I
learned about counter-steering, which is a different
issue. It is criminal that counter-steering is not taught
to every newly - minted motorcycle rider.[...]

Push hard on the handlebar on the side you want to turn quickly too.
Standard training in introductory motorcycle riding class.

--
Tºm Shermªn - 42.435731,-83.985007
I am a vehicular cyclist.

On 7/4/2011 12:05 PM, Winston wrote:
wrote:
On Jul 4, 9:00 am, Frank wrote:
Interesting article on the physics of bike stability:

http://www.newscientist.com/article/...-to-the-drawin...

orhttp://tinyurl.com/3szqyhk

Jim Papadopoulos was once a denizen of rec.bicycle.tech.

- Frank Krygowski

I think that the regular bike had wheels with too much spoke tension.
Had the put low tensioned wheels it would have stayed up, even with
the tied handlebar.

Look closely at 0:11.

http://www.newscientist.com/article/...rd.html?page=1


The 'positive caster' head angle appears
to be the reason why the frame corrects to vertical.
When the front wheel isn't allowed to 'steer into' the
turn, the bike flops over.

The correct answer is: Andrés Muro is trolling Trevor Jeffrey.

--
Tºm Shermªn - 42.435731,-83.985007
I am a vehicular cyclist.