Bike stability physics
Frank Krygowski
http://www.newscientist.com/article/mg21028141.700-bike-to-the-drawing-board.html?page=1
Jim Papadopoulos was once a denizen of rec.bicycle.tech.
- Frank Krygowski
Dan O
> Interesting article on the physics of bike stability:
>
>
> 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".
andre...@aol.com
> Interesting article on the physics of bike stability:
>
>
> 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.
Winston
Look closely at 0:11.
http://www.newscientist.com/article/mg21028141.700-bike-to-the-drawing-board.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
Dan O
> andresm...@aol.com wrote:
> > On Jul 4, 9:00 am, Frank Krygowski<frkry...@gmail.com> wrote:
> >> Interesting article on the physics of bike stability:
>
> >>http://www.newscientist.com/article/mg21028141.700-bike-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.
>
>
> 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.)
Dan O
... almost *magical*...
> ... depth and intricacy of human perception and
> ability.)
thirty-six
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.
Winston
> On Jul 4, 10:05 am, Winston<Wins...@BigBrother.net> wrote:
>> andresm...@aol.com wrote:
>>> On Jul 4, 9:00 am, Frank Krygowski<frkry...@gmail.com> wrote:
>>>> Interesting article on the physics of bike stability:
>>
>>>> http://www.newscientist.com/article/mg21028141.700-bike-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/mg21028141.700-bike-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 bollocks 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
Tºm Shermªn °_°
> [...]
> 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
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.
Tºm Shermªn °_°
The correct answer is: Andrés Muro is trolling Trevor Jeffrey.
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.
Not 'hard'. That would introduce one to pavement rather quickly.
Experiment first and then practice until it is completely
natural. Counter-steering can be a life-saver.
> Standard training in introductory motorcycle riding class.
Yesbut, riding classes are completely optional and
largely ignored. When I sold my last motorcycle, I
demonstrated counter-steering to the new owner by
creating a series of very fast turns down the middle
of my residential street, 'way faster than I could
have done by just leaning.
It was all news to him.
--Winston
Winston
(...)
> The correct answer is: Andrés Muro is trolling Trevor Jeffrey.
Oh. :)
--Winston
Frank Krygowski
> Tºm Shermªn °_° > wrote:
>
>
> > Push hard on the handlebar on the side you want to turn quickly too.
>
> Not 'hard'. That would introduce one to pavement rather quickly.
> Experiment first and then practice until it is completely
> natural. Counter-steering can be a life-saver.
>
> > Standard training in introductory motorcycle riding class.
>
> Yesbut, riding classes are completely optional and
> largely ignored. When I sold my last motorcycle, I
> demonstrated counter-steering to the new owner by
> creating a series of very fast turns down the middle
> of my residential street, 'way faster than I could
> have done by just leaning.
>
> It was all news to him.
Americans, at least, certainly seem quick to think they know as much
as anyone on any subject at all. Witness things like confident
letters to the editor on topics like economics, international
diplomacy, climate change, etc., written by people who never quite
made it through secondary school.
And on subjects that appear easy, like riding a two-wheeler? Hell,
it's _obvious_ there's nothing to learn! If you can balance, you're
an absolute expert, and nobody can teach you anything!
I've wondered if this overconfidence is connected to America's "all
men created equal" concept. Are things different in countries where
class systems are more blatant? Anybody know?
- Frank Krygowski
Dan O
> On Jul 7, 11:15 am, Winston <Wins...@BigBrother.net> wrote:
>
>
>
> > Tºm Shermªn °_° > wrote:
>
> > > Push hard on the handlebar on the side you want to turn quickly too.
>
> > Not 'hard'. That would introduce one to pavement rather quickly.
> > Experiment first and then practice until it is completely
> > natural. Counter-steering can be a life-saver.
>
> > > Standard training in introductory motorcycle riding class.
>
> > Yesbut, riding classes are completely optional and
> > largely ignored. When I sold my last motorcycle, I
> > demonstrated counter-steering to the new owner by
> > creating a series of very fast turns down the middle
> > of my residential street, 'way faster than I could
> > have done by just leaning.
>
> > It was all news to him.
>
> Americans, at least, certainly seem quick to think they know as much
> as anyone on any subject at all. Witness things like confident
> letters to the editor on topics like economics, international
> diplomacy, climate change, etc., written by people who never quite
> made it through secondary school.
>
> And on subjects that appear easy, like riding a two-wheeler? Hell,
> it's _obvious_ there's nothing to learn! If you can balance, you're
> an absolute expert, and nobody can teach you anything!
>
There are many things you can't learn from a book.
> I've wondered if this overconfidence is connected to America's "all
> men created equal" concept. Are things different in countries where
> class systems are more blatant? Anybody know?
>
Do you mean where people "know their place"?
Frank Krygowski
Note that I did not specify "book."
However, non-readers greatly underestimate the number of things one
_can_ learn from a book.
- Frank Krygowski
Dan O
Tºm Shermªn °_°
> Tºm Shermªn °_° > wrote:
>> 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.
>
> Not 'hard'. That would introduce one to pavement rather quickly.
> Experiment first and then practice until it is completely
> natural. Counter-steering can be a life-saver.
>
handlebar width, weight of the motorcycle, and steering geometry.
I would push subjectively "hard" on the handlebars of my 1979 Honda
CB400 to avoid road hazards and errant motorists. Of course, the CB400
has considerably better than average handling for motorcycles of that era.
Pushing with a quarter of that force on the bars of my Earth Cycles
Sunset Lowracer would dump me almost instantly.
>> Standard training in introductory motorcycle riding class.
>
> Yesbut, riding classes are completely optional and
> largely ignored. When I sold my last motorcycle, I
> demonstrated counter-steering to the new owner by
> creating a series of very fast turns down the middle
> of my residential street, 'way faster than I could
> have done by just leaning.
>
> It was all news to him.
I was in Illinois, and the MSF course was mandatory if you were under 18
and wanted to ride on the street legally.
What I wonder about is the level of control on some of the H-D choppers
I see, with the super-slack fork angle and ape-hanger bars above face
height.
Winston
(...)
> I was in Illinois, and the MSF course was mandatory if you were under 18
> and wanted to ride on the street legally.
It was *much* simpler in California ca. 1970
A very simple maneuver demonstration and a simple
multiple-guess exam. I would hear the term 'counter-
steering' for the first time, 24 years later.
> What I wonder about is the level of control on some of the H-D choppers
> I see, with the super-slack fork angle and ape-hanger bars above face
> height.
Darwin in the wind!
--Winston
Peter Cole
Jobst used to hypothesize that the biomechanics of counter-steering a
bicycle was similar enough to running that it was a "hard-wired" skill.
The learning curve is nearly instantaneous because we're just
cross-wiring into a skill we're born with. I think all cyclists
counter-steer, most without knowing it. It's not lectures that help, but
practice. People just don't get much exposure to the need to swerve
suddenly, but it's quite natural, nothing counter-intuitive about it.
It's just a matter of conditioning the reflexes. Mountain biking does
this pretty quickly.
Duane Hebert
> On Jul 7, 6:09 pm, Frank Krygowski<frkry...@gmail.com> wrote:
>> On Jul 7, 8:35 pm, Dan O<danover...@gmail.com> wrote:
>>
>>
>>
>>> On Jul 7, 9:06 am, Frank Krygowski<frkry...@gmail.com> wrote:
>>
>>>> On Jul 7, 11:15 am, Winston<Wins...@BigBrother.net> wrote:
>>
Bradbury is good but
http://en.wikipedia.org/wiki/Slaughterhouse-Five
poo tee weet
Winston
> On 7/7/2011 12:06 PM, Frank Krygowski wrote:
(...)
>> Americans, at least, certainly seem quick to think they know as much
>> as anyone on any subject at all. Witness things like confident
>> letters to the editor on topics like economics, international
>> diplomacy, climate change, etc., written by people who never quite
>> made it through secondary school.
I suppose that all cultures are plagued by hubris
at some point in their history.
http://en.wikipedia.org/wiki/Nazi_Germany
Some longer than others....
http://www.vatican.va/vatican_city_state/index.htm
http://en.wikipedia.org/wiki/Mafia
Though I do see your point.
http://en.wikipedia.org/wiki/Trail_of_Tears
>> And on subjects that appear easy, like riding a two-wheeler? Hell,
>> it's _obvious_ there's nothing to learn! If you can balance, you're
>> an absolute expert, and nobody can teach you anything!
>>
>> I've wondered if this overconfidence is connected to America's "all
>> men created equal" concept. Are things different in countries where
>> class systems are more blatant? Anybody know?
America is as 'class stratified' as any other set of cultures.
Even the 'vast unwashed' try desperately to differentiate
themselves.
http://en.wikipedia.org/wiki/Hip_hop
http://en.wikipedia.org/wiki/Professional_sports
> Jobst used to hypothesize that the biomechanics of counter-steering a
> bicycle was similar enough to running that it was a "hard-wired" skill.
> The learning curve is nearly instantaneous because we're just
> cross-wiring into a skill we're born with. I think all cyclists
> counter-steer, most without knowing it.
Depends on one's definition of the term, I suppose.
Using the 'counter-steering' technique (to advantage) is different from
the course-deviation that occurs when hitting the chord of
a divot in the road, for example. Both are fast direction changes
prompted by leveraging 'center of gravity'.
The former can get you around a corner quickly and safely.
The latter forces you (however temporarily or slightly) into a
direction you hadn't intended. :)
> It's not lectures that help, but
> practice. People just don't get much exposure to the need to swerve
> suddenly, but it's quite natural, nothing counter-intuitive about it.
I don't understand.
'Steering left' to 'go right' is intuitive?
Can you clarify please?
> It's just a matter of conditioning the reflexes. Mountain biking does
> this pretty quickly.
I couldn't agree more (with this first sentence). :)
--Winston
Peter Cole
I don't think there's much to dispute. Counter-steering merely initiates
a fall in the direction you wish to turn. You do that by putting the
tire contact patch to the other side of vertical. You then steer into
the fall, balancing the centripetal and gravitational forces. We do it
all the time, cycling or even walking.
>
> Using the 'counter-steering' technique (to advantage) is different from
> the course-deviation that occurs when hitting the chord of
> a divot in the road, for example. Both are fast direction changes
> prompted by leveraging 'center of gravity'.
I don't understand "chord of a divot" nor "leveraging 'center of gravity'".
> The former can get you around a corner quickly and safely.
> The latter forces you (however temporarily or slightly) into a
> direction you hadn't intended. :)
The only thing that actually forces me in unintended directions are
grooves, like trolley tracks.
>
>> It's not lectures that help, but
>> practice. People just don't get much exposure to the need to swerve
>> suddenly, but it's quite natural, nothing counter-intuitive about it.
>
> I don't understand.
> 'Steering left' to 'go right' is intuitive?
> Can you clarify please?
Sure, being bipeds, we have the need to change the direction of our
momentum (esp when running) with a "contact patch" only at our feet. We
are always dynamically balancing, even when motionless, but when we are
running and need to turn sharply we need to perform exactly the same
maneuver as we do on a bike. It is likely we are born knowing how to do
it. You just have to transfer that innate knowledge to cycling, it's not
something that needs to be taught, just practiced. Most children get it
right away, otherwise they couldn't ride bikes.
>> It's just a matter of conditioning the reflexes. Mountain biking does
>> this pretty quickly.
>
> I couldn't agree more (with this first sentence). :)
When it comes to bike handling skills, mountain biking typically
provides far more frequent situations to develop those skills. Since
it's a matter of reflexive, not book, learning -- a more challenging
environment speeds up the process and keeps the skills sharp. In
addition to turning and braking skills, it also improves a broad range
of balance, reaction time, spacial perception capacities -- especially
useful for older riders, as research seems to indicate a very strong
"use it or lose it" phenomenon, particularly with aging.
Frank Krygowski
>
> Jobst used to hypothesize that the biomechanics of counter-steering a
> bicycle was similar enough to running that it was a "hard-wired" skill.
> The learning curve is nearly instantaneous because we're just
> cross-wiring into a skill we're born with. I think all cyclists
> counter-steer, most without knowing it. It's not lectures that help, but
> practice.
I think having the background knowledge helps. In my mind, it's like
learning to play an instrument. We're all hard-wired to know how to
move our fingers; and lots of people get quite good on instruments
without lessons, just bumbling on their own, so to speak.
But a good teacher will give important tips, and will make the student
conscious of aspects of motion that the student might never realize on
his own. A specific example: "When lifting your finger free [of the
hole, the key, the fret, the string, whatever] try not to raise it so
high. That will allow you to increase your speed."
Such tips don't increase facility immediately. But as the student
thinks about them (perhaps subconsciously), internalizes them and
practices them, they do eventually help. I think the same is true of
certain on-bike moves.
In addition, coaches in any sport engage in the same sort of analyzing
and teaching, and get the athletes do a lot of educated practice. Few
question that it can be valuable.
- Frank Krygowski
Frank Krygowski
>
> When it comes to bike handling skills, mountain biking typically
> provides far more frequent situations to develop those skills.
So does delivering newspapers by bike in a huge suburban
neighborhood. At least, that was my experience.
- Frank Krygowski
Peter Cole
It's not that complicated. Children can do it.
Peter Cole
Well for anyone needing the money I suggest a paper route instead of a
mountain bike -- to the extent that people read papers anymore.
Andre Jute
> Interesting article on the physics of bike stability:
>
> http://www.newscientist.com/article/mg21028141.700-bike-to-the-drawin...
>
> orhttp://tinyurl.com/3szqyhk
>
> Jim Papadopoulos was once a denizen of rec.bicycle.tech.
>
> - Frank Krygowski
Thanks for that, Frank; most entertaining.
It's difficult to see how we are any forarder than we were in the late
1960s when a fellow called Jones used his wife's bike to prove, by
mounting the fork backwards, that trail was irrelevant to bike
stability. I'm not so sure, without looking it up, that Jones didn't
also prove that the other engineering shibboleth, the gyroscopic force
of spinning wheels, is also a deadweight of worn-out chains on bike
development. So, forty years later Ruina says that we have the
formulae, we just don't know what they mean. Maybe: he's closer to it
than I am, and it is a clearly a very complicated subject I just don't
have the time to master; I'm just glad that the traditional diamond
frame works so well. However, in the sequence of science, before you
can know what the formulae mean, you must first discover which are
important and should be given greater weight, and those buggers
haven't yet done that. They don't appear even to have added
significantly to Jones's list of what ISN'T the crucial factor.
I'd be delighted to be convinced otherwise, that they've made a
significant stride, but all I see is academic doclat-filler. The guy
at Batavus has it right: the bicycle in its most developed form, the
racing bike, is somewhere near perfection, developed by tiny advances
in the hands of users, and for a few other bikes for specific
purposes, there will be some fiddling around the edges. I'm not
impressed with these great strides of science: I wrote to my own bike
maker, Utopia, two years ago that they should beware of making the
smaller frames on proportionately shorter wheelbases because a middle-
aged market -- slower riders with slowing reflexes -- will appreciate
the stability of the longer wheelbases, something I discovered by
comparing my three Dutch city bikes and the various wooden geribikes I
experimented with a few years ago. So that's Batavus's big discovery
from this research? Gee, maybe they should talk to their customers
more often.
Sorry to be negative about guys who have the right intention, but
there's nothing new here except a better class of self-promotion for
scientists.
Andre Jute
Visit Jute on Bicycles at
http://coolmainpress.com/BICYCLING.html
Frank Krygowski
These children can do it:
http://www.youtube.com/watch?v=nKofhkgk7h8
I bet they had a lesson or two, though.
- Frank Krygowski
Winston
> On 7/8/2011 10:17 AM, Winston wrote:
(...)
>> Depends on one's definition of the term, I suppose.
>
> I don't think there's much to dispute. Counter-steering merely initiates
> a fall in the direction you wish to turn. You do that by putting the
> tire contact patch to the other side of vertical. You then steer into
> the fall, balancing the centripetal and gravitational forces. We do it
> all the time, cycling or even walking.
In my part of the world, new riders turn by initially
steering and leaning into the new direction of travel.
I have yet to see a new bicycle rider counter-steer on purpose
(and remain in control).
It is counter-intuitive. :)
>> Using the 'counter-steering' technique (to advantage) is different from
>> the course-deviation that occurs when hitting the chord of
>> a divot in the road, for example. Both are fast direction changes
>> prompted by leveraging 'center of gravity'.
>
> I don't understand "chord of a divot" nor "leveraging 'center of gravity'".
A chord of a divot is a groove. A recess.
You leverage 'center of gravity' by (in your words):
"[initiating] a fall in the direction you wish to turn."
>> The former can get you around a corner quickly and safely.
>> The latter forces you (however temporarily or slightly) into a
>> direction you hadn't intended. :)
>
> The only thing that actually forces me in unintended directions are
> grooves, like trolley tracks.
Sure, any groove, recess, divot, curb, etc. can do that.
>>> It's not lectures that help, but
>>> practice. People just don't get much exposure to the need to swerve
>>> suddenly, but it's quite natural, nothing counter-intuitive about it.
>>
>> I don't understand.
>> 'Steering left' to 'go right' is intuitive?
>> Can you clarify please?
>
> Sure, being bipeds, we have the need to change the direction of our
> momentum (esp when running) with a "contact patch" only at our feet. We
> are always dynamically balancing, even when motionless, but when we are
> running and need to turn sharply we need to perform exactly the same
> maneuver as we do on a bike. It is likely we are born knowing how to do
> it. You just have to transfer that innate knowledge to cycling, it's not
> something that needs to be taught, just practiced.
> Most children get it
> right away, otherwise they couldn't ride bikes.
I misunderstand your terminology.
Could you view this clip and tell me if this rider is
turning conventionally or counter-steering, please?
http://www.youtube.com/watch?v=SEDbWVor1b8
Maybe it is one of those 'perception' things, but
I would swear that he is turning and leaning in
the same direction, (into the turn, conventionally).
Do you see any difference between the way he is
turning and the way this rider is turning?:
http://www.youtube.com/watch?v=C848R9xWrjc
(Starting at ~2:36)
I sure do.
>>> It's just a matter of conditioning the reflexes. Mountain biking does
>>> this pretty quickly.
>>
>> I couldn't agree more (with this first sentence). :)
>
> When it comes to bike handling skills, mountain biking typically
> provides far more frequent situations to develop those skills.
In the same manner that being caged with a wild lion poses
many more opportunities to develop one's lion taming skills
than if one were to relax in front of the tube, for example?
> Since it's a matter of reflexive, not book, learning --
The technique of turning the bars in the opposite direction
of intended travel on purpose (counter steering) is, for
most folks terra incognita. We steer and lean 'into' our turns
and for a vast majority of folks, that works just fine for the
entire period spent on two wheels. There is nothing intuitive
about counter-steering, IMVHO.
> a more challenging
> environment speeds up the process and keeps the skills sharp. In
> addition to turning and braking skills, it also improves a broad range
> of balance, reaction time, spacial perception capacities -- especially
> useful for older riders, as research seems to indicate a very strong
> "use it or lose it" phenomenon, particularly with aging.
I think your test subjects self-select, then.
Unlike the unfortunates who crashed because they never learned
how to counter-steer.
http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
--Winston
Michael Press
Peter Cole <peter...@verizon.net> wrote:
Mountain biking is extreme.
Ride your neighborhood streets,
keep a straight line,
keep you eyes on the road,
do not ride over bumps, holes,
or debris and you must then
steer quickly. Presto chango!
--
Michael Press
thirty-six
No idea, I'm an Englishman, I read the book (R. Van der Plas, Bicycle
racing), applied the knowledge and was surprised at the absolute
validity of the procedure. I believe in giving the bar a quick shove
and be just as quick in catching the fall.
thirty-six
>
> I think you'll find that quadrupeds also lean into corners when moving
> at any speed.
The dogs.
http://www.youtube.com/watch?v=EcmjNvBbGJs&feature=player_detailpage#t=36s
thirty-six
Took me 15 years before I found out and practiced it. It took a book
to tell me. No-one had thought I had any problem in steering. Making
a turn in half the length is pleasing.
>
> > a more challenging
> > environment speeds up the process and keeps the skills sharp. In
> > addition to turning and braking skills, it also improves a broad range
> > of balance, reaction time, spacial perception capacities -- especially
> > useful for older riders, as research seems to indicate a very strong
> > "use it or lose it" phenomenon, particularly with aging.
>
> I think your test subjects self-select, then.
>
> Unlike the unfortunates who crashed because they never learned
> how to counter-steer.http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at...
>
> --Winston
thirty-six
Wide squidgy tyres and a long wheelbase with a good amount of trail
are easiest to ride. Racing bikes, especially criterium bikes present
an effort (to steer) that can be unwelcome for the lesiure rider. It
is the touring bike, like a racer, with fat tyres where you will find
the most efficiency for easy rolling along the lanes.
Peter Cole
> In my part of the world, new riders turn by initially
> steering and leaning into the new direction of travel.
> I have yet to see a new bicycle rider counter-steer on purpose
> (and remain in control).
> It is counter-intuitive. :)
Straight line cycling involves steering the contact patch under the
center of mass. This must be done constantly, or else you fall down. If
you turn without counter-steering, you will fall down. Any rider, even a
novice, who can turn a bike is counter-steering, whether they realize it
or not. Counter-steering is not counter-intuitive to those who
understand physics, nor to those who don't think about it. It is only
the minority that fall into neither category that find it so.
>> Most children get it
>> right away, otherwise they couldn't ride bikes.
>
> I misunderstand your terminology.
> Could you view this clip and tell me if this rider is
> turning conventionally or counter-steering, please?
>
> http://www.youtube.com/watch?v=SEDbWVor1b8
Recumbent bicycles don't change the physics.
> Maybe it is one of those 'perception' things, but
> I would swear that he is turning and leaning in
> the same direction, (into the turn, conventionally).
At low speeds and gradual turns the amount of counter-steer is so small
it's hard to see.
> Do you see any difference between the way he is
> turning and the way this rider is turning?:
> http://www.youtube.com/watch?v=C848R9xWrjc
> (Starting at ~2:36)
>
> I sure do.
Counter-steering becomes more obvious during quick turns, but it's
really (it must be, according to physics) a continuum with ever more
being applied the more sudden the turn.
Riding a bike is like balancing a broom on your palm. Most people can do
this without understanding the physics, and can even run and turn
corners while doing it. It's not difficult, nor does it require
intuition, counter or otherwise.
>
>>>> It's just a matter of conditioning the reflexes. Mountain biking does
>>>> this pretty quickly.
>>>
>>> I couldn't agree more (with this first sentence). :)
>>
>> When it comes to bike handling skills, mountain biking typically
>> provides far more frequent situations to develop those skills.
>
> In the same manner that being caged with a wild lion poses
> many more opportunities to develop one's lion taming skills
> than if one were to relax in front of the tube, for example?
Probably more like learning to ski, an uneven slope will train necessary
balancing and coordination skills faster than a smooth one.
> > Since it's a matter of reflexive, not book, learning --
>
> The technique of turning the bars in the opposite direction
> of intended travel on purpose (counter steering) is, for
> most folks terra incognita.
So you claim, but physics says that is not so.
> We steer and lean 'into' our turns
> and for a vast majority of folks, that works just fine for the
> entire period spent on two wheels. There is nothing intuitive
> about counter-steering, IMVHO.
To lean into a turn requires first steering in the opposite direction,
always, otherwise how do you initiate the lean? You can cock your upper
body one way in an attempt to lean, but that will just force your lower
body in the opposite direction. Climbing a rope ladder demonstrates this.
> > a more challenging
> > environment speeds up the process and keeps the skills sharp. In
> > addition to turning and braking skills, it also improves a broad range
> > of balance, reaction time, spacial perception capacities -- especially
> > useful for older riders, as research seems to indicate a very strong
> > "use it or lose it" phenomenon, particularly with aging.
>
> I think your test subjects self-select, then.
I don't have any test subjects, I'm just summarizing current research.
Things like balance, timing, spacial perception, eye-hand coordination,
etc. can be improved with training, like endurance and strength. Also
like endurance and strength, they tend to decline with age. Focused
training can offset that to a significant degree.
> Unlike the unfortunates who crashed because they never learned
> how to counter-steer.
> http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
It's unlikely that that rider crashed from "not learning
counter-steering", since they all must have been counter-steering to
negotiate the twisty road they had been following for several miles. In
the video that shows the actual crash:
http://www.youtube.com/watch?v=sny83dnP4Kc&NR=1&feature=fvwp at 8:25, it
is impossible to determine the cause since the crashing rider has
already lost the line by the time he is in view of the following camera
rider. A poor example to make any point, or to identify the cause of the
crash.
Counter-steering must be performed to steer any bicycle or motorcycle
around curves, it's just not obvious unless the turn is abrupt. What you
call "counter-steering" is just abrupt turning, which uses the same
motions as gradual turning, only in a more exaggerated way. If you study
the physics, you'll see it must be so. You could come to the same
conclusion by riding a bicycle observantly.
Steering a bicycle is just creating a controlled rate fall in the
direction you want to go, counter-steering is the only way to initiate
that fall.
Dan O
> In article <iv6ql7$g5...@dont-email.me>,
This is a good approach, except that riding over bumps, holes, and
debris can teach you effects that you can't possibly learn any other
way. This is not to say one should intentionally seek out every bump,
hole and patch of loose gravel he can find (though this *does* seem to
be the mode of operation for many curious thrill-seeking kids learning
about the world) - just that you the rider should take the world as it
comes and not categorize any experience as entirely negative (or
entirely positive).
Dan O
My own perspective is rather unique. Sure I got my first bicycle at
age eight and learned to make it go and make it stop and change
direction and had a lot of fun and freedom and... yeah.
Then around age nine I got a Honda Trail 50 motorbike and had even
more fun and more freedom. My brother and I rode the wheels off that
thing.
Then at age twelve I tried motocross racing on a Yamaha MX 100, fell
in the mud about fifteen times in one lap, did a little better the
next time out in the dry, but never did it long enough to get good
before my dad took the knobbies off and we went flatracking.
Of course at first it was just ride around the track like a baby bird
trying to loearn to fly, but between going to the track every summer
weekend, riding around and around (and around) impromptu courses
wherever I might create one (oval driveways, scrambles up and around a
hollow... anything). Watching the pros and hanging out with them and
trying to emulate. Going around and around and around, lap times
decreasing, getting faster and faster as better ways to nake it
through the turns without slowing down so much, actually *feeling*
what made the lap times decrease without really consciously being
aware of time - just strangely cognizant of going fast on two
wheels...
By the time I went pro, the concept of countersteering (if I am even
knowing what you guys are talking about) - as well as who knows how
many other technicalities of physics and motion - was intimately
ingrained in my human apparatus.
So anyway my experience is kind of a weird one. And I *know* that I
don't know everything - so far from it - more nearly the inverse. But
you can't discount the value (even eminence) of learning this way
>
>
> > > a more challenging
> > > environment speeds up the process and keeps the skills sharp. In
> > > addition to turning and braking skills, it also improves a broad range
> > > of balance, reaction time, spacial perception capacities -- especially
> > > useful for older riders, as research seems to indicate a very strong
> > > "use it or lose it" phenomenon, particularly with aging.
>
Boy howdy ain't it the truth; and on top of that, *using* it becomes
harder and riskier as our bodies become less durable.
But I keep trying - with a passion :-)
<snip>
Dan O
>
> It's unlikely that that rider crashed from "not learning
> counter-steering", since they all must have been counter-steering to
> negotiate the twisty road they had been following for several miles. In
> is impossible to determine the cause since the crashing rider has
> already lost the line by the time he is in view of the following camera
> rider. A poor example to make any point, or to identify the cause of the
> crash.
>
> Counter-steering must be performed to steer any bicycle or motorcycle
> around curves, it's just not obvious unless the turn is abrupt. What you
> call "counter-steering" is just abrupt turning, which uses the same
> motions as gradual turning, only in a more exaggerated way. If you study
> the physics, you'll see it must be so. You could come to the same
> conclusion by riding a bicycle observantly.
>
> Steering a bicycle is just creating a controlled rate fall in the
> direction you want to go, counter-steering is the only way to initiate
> that fall.
Good to "see" you again :-) Positive waves, man
Winston
(Counter-steering technique)
> Took me 15 years before I found out and practiced it. It took a book
> to tell me. No-one had thought I had any problem in steering. Making
> a turn in half the length is pleasing.
I heard that in motorcycle 'super bike' school, there is a
counter-steering U-turn maneuver taught that gets you from the
left - turn lane into the #1 lane in the opposite direction
without touching the #2 lane, even with a big motorcycle.
It is done *while watching the horizon*.
Yikes!
--Winston
Winston
> Winston<Win...@BigBrother.net> considered Fri, 08 Jul 2011 23:33:36
> -0700 the perfect time to write:
(...)
>> Unlike the unfortunates who crashed because they never learned
>> how to counter-steer.
>> http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
>>
> Just because people don't know they are doing it doesn't mean they
> aren't.
I'm confused here, Phil. Help!
In the video above, the rider that lost control of
his bike and unintentionally merged into the soft
shoulder had every reason to counter-steer.
He 'bet the house' on his ability to get around
those mountain corners. Riders two seconds in front
of him made those corners safely, without waggling
their tailbones from port to starboard and back.
Was he counter-steering? Really?
Or did he exhaust himself leaning through those
turns conventionally?
> How do you think that any rider initiates "leaning into the turn"?
Just as in the video I cited.
Lean your torso in the direction of intended travel and
ease the bars *into* the turn. I did it that way
for too many years, though not as dramatically as we
see in the video.
That is fundamentally different from easing your bars
*out* of the turn and using the motorcycle's mass to
lean it into the intended direction.
These are two different ways of turning.
Smart riders use either technique as the
situation warrants. A long freeway sweep at [mumble]
miles per hour can be done very safely by moderately
leaning into the new direction while correcting the
bar position to establish a new equilibrium through
the turn, for example.
> Think about Newton's laws of motion while you work it out.
His first law from
http://teachertech.rice.edu/Participants/louviere/Newton/law1.html :
"An object at rest will remain at rest unless acted on by an
unbalanced force. An object in motion continues in motion
with the same speed and in the same direction unless acted
upon by an unbalanced force."
Moving the CG of the bike/rider system to the inside of
the turn is an excellent example of an 'unbalanced force'.
Sometimes that is the best way to turn your bike.
Sometimes it is just an unsafe maneuver.
That is what I'm on about.
--Winston
If it means that just one new rider learns the
counter-steering technique as a result of this
otherwise baffling controversy, it will be well
worth the effort, IMVHO.
thirty-six
If you spin the wheel the M'bike will turn into the camber anyway, you
just keep it going and you can turn around a bike or rear wheel drive
car or waggon on the spot. You still need to balance the bike so
active steering input is required throughout.
thirty-six
> Phil W Lee wrote:
> > -0700 the perfect time to write:
>
> (...)
>
> >> Unlike the unfortunates who crashed because they never learned
> >> how to counter-steer.
>
> "An object at rest will remain at rest unless acted on by an
> unbalanced force. An object in motion continues in motion
> with the same speed and in the same direction unless acted
> upon by an unbalanced force."
>
> Moving the CG of the bike/rider system to the inside of
> the turn is an excellent example of an 'unbalanced force'.
>
> Sometimes that is the best way to turn your bike.
> Sometimes it is just an unsafe maneuver.
>
> That is what I'm on about.
>
> --Winston
>
> If it means that just one new rider learns the
> counter-steering technique as a result of this
> otherwise baffling controversy, it will be well
> worth the effort, IMVHO.
Use the forced turn at speed so you dont run out of road. It's a lot
easier than using brakes on a falling camber. By using the forced
turn the rider can turn in much later and therefore get an earlier
exit from the corner at greater speed and so consider the next bend
much earlier during an easy exit. In many cases, using brakes is not
only for cissies and is slow but is also dangerous in comparison to
sweeping through a series of bends at speed. Self encouragement of
the technique is important so as to perfect it. You should be able to
spot your exit point on a bend to the inch before you turn-in. Only
when you can do this reliably should you go hit the local chicanes at
speed.
Michael Press
<d325d04e-e2b3-49de...@gv8g2000vbb.googlegroups.com>,
Dan O <danov...@gmail.com> wrote:
Who says we will always succeed?
--
Michael Press
thirty-six
> > Winston<Wins...@BigBrother.net> considered Fri, 08 Jul 2011 23:33:36
> > -0700 the perfect time to write:
>
> (...)
>
> >> Unlike the unfortunates who crashed because they never learned
> >> how to counter-steer.
>
> > Just because people don't know they are doing it doesn't mean they
> > aren't.
>
> I'm confused here, Phil. Help!
>
> In the video above, the rider that lost control of
> his bike and unintentionally merged into the soft
> shoulder had every reason to counter-steer.
>
> He 'bet the house' on his ability to get around
> those mountain corners. Riders two seconds in front
> of him made those corners safely, without waggling
> their tailbones from port to starboard and back.
>
> Was he counter-steering? Really?
>
> Or did he exhaust himself leaning through those
> turns conventionally?
>
were good earlier on but the novice method does not turn the bike
between corners quick enough and so he ran out of road. I could see
it for a few bends before, he was turning in early and exiting late,
to get over properly he should have used his brake to set himself up
with the beginners method.
> > How do you think that any rider initiates "leaning into the turn"?
>
> Just as in the video I cited.
>
> Lean your torso in the direction of intended travel and
> ease the bars *into* the turn. I did it that way
> for too many years, though not as dramatically as we
> see in the video.
>
> That is fundamentally different from easing your bars
> *out* of the turn and using the motorcycle's mass to
> lean it into the intended direction.
It's not gravity acting on the mass, it's the forward momemtum which
carries the bike straight on but the front wheel shoots sideways so
that the bike topples (quicker if you touch the front brake).
>
> These are two different ways of turning.
>
> Smart riders use either technique as the
> situation warrants. A long freeway sweep at [mumble]
> miles per hour can be done very safely by moderately
> leaning into the new direction while correcting the
> bar position to establish a new equilibrium through
> the turn, for example.
>
> > Think about Newton's laws of motion while you work it out.
>
> His first law fromhttp://teachertech.rice.edu/Participants/louviere/Newton/law1.html:
Winston
> On 7/9/2011 2:33 AM, Winston wrote:
(...)
>> I misunderstand your terminology.
>> Could you view this clip and tell me if this rider is
>> turning conventionally or counter-steering, please?
>>
>> http://www.youtube.com/watch?v=SEDbWVor1b8
>
> Recumbent bicycles don't change the physics.
Yes. At last we agree.
May I ask an entirely different question then?
http://www.youtube.com/watch?v=SEDbWVor1b8
Could you view this clip and tell me if this rider is
turning conventionally or counter-steering, please?
>> Maybe it is one of those 'perception' things, but
>> I would swear that he is turning and leaning in
>> the same direction, (into the turn, conventionally).
>
> At low speeds and gradual turns the amount of counter-steer is so small
> it's hard to see.
Did you detect the presence of any counter-steering
at all in the video? I didn't.
Another fundamentally new question:
Do you see any difference between the way he is
turning and the way this rider is turning?:
http://www.youtube.com/watch?v=C848R9xWrjc
(Starting at ~2:36)
>> I sure do.
>
> Counter-steering becomes more obvious during quick turns, but it's
> really (it must be, according to physics) a continuum with ever more
> being applied the more sudden the turn.
For people who *do* counter-steer, that is true.
> Riding a bike is like balancing a broom on your palm. Most people can do
> this without understanding the physics, and can even run and turn
> corners while doing it. It's not difficult, nor does it require
> intuition, counter or otherwise.
In this second sentence and yesterday morning, you implied that counter-
steering *is* understood intuitively.
"Intuition (knowledge): understanding without apparent effort"
Peter Cole > "I think all cyclists counter-steer, most without knowing it."
If I'd made that assertion, I would have retracted it too. :)
Unicyclists are 'cyclists' too, yes?
How do they counter-steer without benefit of a front wheel
to do it with?
>>>>> It's just a matter of conditioning the reflexes. Mountain biking does
>>>>> this pretty quickly.
>>>>
>>>> I couldn't agree more (with this first sentence). :)
>>>
>>> When it comes to bike handling skills, mountain biking typically
>>> provides far more frequent situations to develop those skills.
>>
>> In the same manner that being caged with a wild lion poses
>> many more opportunities to develop one's lion taming skills
>> than if one were to relax in front of the tube, for example?
>
> Probably more like learning to ski, an uneven slope will train necessary
> balancing and coordination skills faster than a smooth one.
Either way, I feel that it is proper to share a few words
of advice and to show a demonstration of proper technique
before loosing a new rider or skier into an unforgiving
situation. I feel it is cruel to hold back those key facts
that can mean the difference between a lifetime enjoying
outdoor sports and a lifetime 'just surviving' with a serious
injury.
>> > Since it's a matter of reflexive, not book, learning --
>>
>> The technique of turning the bars in the opposite direction
>> of intended travel on purpose (counter steering) is, for
>> most folks terra incognita.
>
> So you claim, but physics says that is not so.
This guy is counter-steering then?
http://media1.break.com/dnet/media/2007/10/15oct2-leaning-into-turn.jpg
I am plagued by the feeling that we mean different things
by the term 'counter-steering'.
>> We steer and lean 'into' our turns
>> and for a vast majority of folks, that works just fine for the
>> entire period spent on two wheels. There is nothing intuitive
>> about counter-steering, IMVHO.
>
> To lean into a turn requires first steering in the opposite direction,
One can move one's torso at the hips and lean without
benefit of handle bars. That is how most of us turn a
bicycle or motorcycle.
> always, otherwise how do you initiate the lean? You can cock your upper
> body one way in an attempt to lean, but that will just force your lower
> body in the opposite direction.
The net effect is to shift the center of gravity of the
bike / rider system, initiating a normal turn in the
same direction as the shift.
Climbing a rope ladder demonstrates this.
The center of mass is *above* the fulcrum when
climbing a rope ladder? Really?
Advise less starch in your ropes. :)
(...)
> I don't have any test subjects, I'm just summarizing current research.
> Things like balance, timing, spacial perception, eye-hand coordination,
> etc. can be improved with training, like endurance and strength. Also
> like endurance and strength, they tend to decline with age. Focused
> training can offset that to a significant degree.
I understand and agree with the implications of 'brain plasticity'.
That concept has stunningly little to do with the counter-steering
technique.
>> Unlike the unfortunates who crashed because they never learned
>> how to counter-steer.
>> http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
>
> It's unlikely that that rider crashed from "not learning
> counter-steering", since they all must have been counter-steering to
> negotiate the twisty road they had been following for several miles.
Most of them were. He was waggling his tailbone to drag his
bike into the turns. Please review the video once again?
(Particularly, sequences starting at 4:49, 5:43, 6:08, 6:26, 6:35 ..)
His crash sequence starting at 7:51 is textbook 'non-counter-steer'.
At 7:51 he should have been finessing his left handgrip away from
his body instead of repeating his earlier 'leaning mistakes'.
He ran out of road, panicked and Whoops! Into the dirt.
That is an absolutely classic illustration of what happens.
I hope he wasn't hurt.
> In the video that shows the actual crash:
> http://www.youtube.com/watch?v=sny83dnP4Kc&NR=1&feature=fvwp at 8:25, it
> is impossible to determine the cause since the crashing rider has
> already lost the line by the time he is in view of the following camera
> rider. A poor example to make any point, or to identify the cause of the
> crash.
I agree. The video I cited earlier reveals the issue clearly.
> Counter-steering must be performed to steer any bicycle or motorcycle
> around curves,
One can merely lean into the turn as shown in the earlier video.
It is improper technique and dangerous in many situations,
but lots of us do it without any counter-steering.
> it's just not obvious unless the turn is abrupt. What you
> call "counter-steering" is just abrupt turning, which uses the same
> motions as gradual turning, only in a more exaggerated way.
It is possible to accomplish the most gradual turn by counter-steering.
Very gradual turns can be done safely by very moderate leaning, too.
I've done it both ways. They are fundamentally different.
> If you study the physics, you'll see it must be so.
The physics disagree.
http://www.youtube.com/watch?v=6yc9mmT62lQ
Does Kurt counter-steer with his front wheel
suspended in the air? What is the coefficient
of friction of nitrogen? :)
> You could come to the same
> conclusion by riding a bicycle observantly.
My observations result in the opposite conclusion.
> Steering a bicycle is just creating a controlled rate fall in the
> direction you want to go, counter-steering is the only way to initiate
> that fall.
Kurt crossed the country by leaning.
Leaning isn't 'counter-steering'.
:)
--Winston
Winston
> On Jul 9, 6:13 pm, Winston<Wins...@BigBrother.net> wrote:
(...)
>> If it means that just one new rider learns the
>> counter-steering technique as a result of this
>> otherwise baffling controversy, it will be well
>> worth the effort, IMVHO.
>
> Use the forced turn at speed so you dont run out of road. It's a lot
> easier than using brakes on a falling camber. By using the forced
> turn the rider can turn in much later and therefore get an earlier
> exit from the corner at greater speed and so consider the next bend
> much earlier during an easy exit. In many cases, using brakes is not
> only for cissies and is slow but is also dangerous in comparison to
> sweeping through a series of bends at speed. Self encouragement of
> the technique is important so as to perfect it. You should be able to
> spot your exit point on a bend to the inch before you turn-in. Only
> when you can do this reliably should you go hit the local chicanes at
> speed.
Exactly.
--Winston
Tºm Shermªn °_°
> Peter Cole > "I think all cyclists counter-steer, most without knowing it."
>
> If I'd made that assertion, I would have retracted it too. :)
> Unicyclists are 'cyclists' too, yes?
>
> How do they counter-steer without benefit of a front wheel
> to do it with?
Counter-steering does *not* work when cycling on a trike.
--
Tºm Shermªn - 42.435731°N, 83.985007°W
I am a vehicular cyclist.
Winston
> On 7/9/2011 2:03 PM, Winston wrote:
>> Peter Cole > "I think all cyclists counter-steer, most without knowing
>> it."
>>
>> If I'd made that assertion, I would have retracted it too. :)
>> Unicyclists are 'cyclists' too, yes?
http://www.youtube.com/watch?v=UmkxGtOw1l4
He claims he leans to turn. He's really counter-steering,
without being aware of it too, yes?
>> How do they counter-steer without benefit of a front wheel
>> to do it with?
>
> Counter-steering does *not* work when cycling on a trike.
It is also notoriously ineffective when driving a schoolbus
or a tractor or a jet plane or a rocket or a car or a truck
or many different kinds of vehicle.
--Winston <-- Just call me "Mr. Helpful"
thirty-six
> Winston <Wins...@BigBrother.net> considered Sat, 09 Jul 2011 12:03:34
> -0700 the perfect time to write:
>
>
>
> >benefit of handle bars. That is how most of us turn a
> >bicycle or motorcycle.
>
It does. I twist the saddle with my hips, the rear frame mo ves with
the saddle, the front steers in the opposite direction, the lean
develops in the direction the saddle was twisted and the bike rides an
arc in that direction until a further input at the saddle, in the
opposite direction, is used to end the turn.
> Think of Newton's laws of motion.
>
> >One can merely lean into the turn as shown in the earlier video.
> >It is improper technique and dangerous in many situations,
> >but lots of us do it without any counter-steering.
>
> Where does the force come from?
My abdomen, through my hips.
>
>
>
> >It is possible to accomplish the most gradual turn by counter-steering.
> >Very gradual turns can be done safely by very moderate leaning, too.
> >I've done it both ways. They are fundamentally different.
>
> No, they are identical.
You don't understand! Ride no hands and think what you are doing to
steer around an obstruction in the road at about 12mph. Oh hold on,
you have an injury which possibly prevents normal operation. In which
case, stop arguing.
>
> >Kurt crossed the country by leaning.
> >Leaning isn't 'counter-steering'.
>
> No, but countersteering is the only way that the rider can initiate a
> lean.
This rider can initiate a lean by not only twisting his hips, with a
proper saddle (no cutaway) but also by simply applying more pressure
to one side of the bike or another, whether through the saddle by
rocking the pelvis or through the pedals. No handlebar contact is
required.
thirty-six
$southslope.net"> wrote:
> On 7/9/2011 2:03 PM, Winston wrote:
>
> > Peter Cole > "I think all cyclists counter-steer, most without knowing it."
>
> > If I'd made that assertion, I would have retracted it too. :)
> > Unicyclists are 'cyclists' too, yes?
>
> > How do they counter-steer without benefit of a front wheel
> > to do it with?
>
> Counter-steering does *not* work when cycling on a trike.
Never mind, you can fall asleep in the middle of the road still
sitting up until BANG!
thirty-six
> Winston <Wins...@BigBrother.net> considered Sat, 09 Jul 2011 10:13:11
> -0700 the perfect time to write:
>
>
>
> >Phil W Lee wrote:
> >> -0700 the perfect time to write:
>
> >(...)
>
> >>> Unlike the unfortunates who crashed because they never learned
> >>> how to counter-steer.
>
> >> Just because people don't know they are doing it doesn't mean they
> >> aren't.
>
> >I'm confused here, Phil. Help!
>
> >In the video above, the rider that lost control of
> >his bike and unintentionally merged into the soft
> >shoulder had every reason to counter-steer.
>
> >He 'bet the house' on his ability to get around
> >those mountain corners. Riders two seconds in front
> >of him made those corners safely, without waggling
> >their tailbones from port to starboard and back.
>
> >Was he counter-steering? Really?
>
You really are being an ass here. The term is recognised in
motorcycling and is a concious and determined effort to initiate a
turn by forcing the steering in the opposite direction one intends the
machine to go. There is no degree of countersteering, the term
denotes a specific effort, shoving the tiller t'other way.
>
>
>
> >Or did he exhaust himself leaning through those
> >turns conventionally?
>
> "conventionally" would be by countersteering - in fact there is no
> other way short of fitting trainer wheels or a sidecar.
Conventially means the lazyboy method of letting the bike drive
itself, no concious effort, no determined steering in the wrong
direction.
> His problem was that he was trying to use bodyshift techniques
> /instead/ of proper (counter)steering.
If he'd have got it right and a little slower, the body movements
would work. Counter steering though is not a naturally learned skill
for the vast majority of riders. You of course are the exception.
> Bodyshifting is irrelevant and unnecessary until you are reaching the
> limit of ground clearance.
Wrong! Bodyshifting can get a rider out of trouble when he finds he
really is going too fast for a corner. It involves transferring all
weight to the outer pedal/peg and turning in the body to where the
rider wishes to go. It should get a cyclist about 3ft of roadspace
which wasn't there. I believe there is some effect with a motorbike,
but it is harder to assess and probably little more than a tyre's
width when riding a heavy motorbike.
>
>
>
> >> How do you think that any rider initiates "leaning into the turn"?
>
> >Just as in the video I cited.
>
> >Lean your torso in the direction of intended travel and
> >ease the bars *into* the turn. I did it that way
> >for too many years, though not as dramatically as we
> >see in the video.
>
> What were you pushing against to lean your torso?
>
>
>
> >That is fundamentally different from easing your bars
> >*out* of the turn and using the motorcycle's mass to
> >lean it into the intended direction.
>
> >These are two different ways of turning.
>
> Yes, left and right.
>
>
>
>
>
> >Smart riders use either technique as the
> >situation warrants. A long freeway sweep at [mumble]
> >miles per hour can be done very safely by moderately
> >leaning into the new direction while correcting the
> >bar position to establish a new equilibrium through
> >the turn, for example.
>
> > > Think about Newton's laws of motion while you work it out.
>
> >His first law from
> >http://teachertech.rice.edu/Participants/louviere/Newton/law1.html:
>
> >"An object at rest will remain at rest unless acted on by an
> > unbalanced force. An object in motion continues in motion
> > with the same speed and in the same direction unless acted
> > upon by an unbalanced force."
>
> >Moving the CG of the bike/rider system to the inside of
> >the turn is an excellent example of an 'unbalanced force'.
>
> So how do you move the CG?
> What sideways force do you apply to the mass of the rider and
> (motor)cycle except through the steering?
>
>
>
> >Sometimes that is the best way to turn your bike.
> >Sometimes it is just an unsafe maneuver.
>
> >That is what I'm on about.
>
> >--Winston
>
> >If it means that just one new rider learns the
> >counter-steering technique as a result of this
> >otherwise baffling controversy, it will be well
> >worth the effort, IMVHO.
>
> Well, they can't ride if they don't already do it, but it is certainly
> worthwhile if they understand what they are doing.
> The video you posted of the snail's pace racer wannabe falling off is
> the proof of that.
Yes Mr Perfect Rider.
thirty-six
Er, actually quite useful when driving a recirulating ball steering
box with cross ply tyres. Gets the speed up of a stiff steering
linkage due to the initial assistance of the self-centring geometry.
Cross ply tyres can takke a significant steering load before they
actually change the wheels direction. Oddly though, drivers do it
today on modern cars with rack and pinion and radials, sometimes very
low profile ones at that. Seems that this swing out, swing in
steering method is too ingrained to unlearn for many drivers.
thirty-six
> thirty-six <thirty-...@live.co.uk> considered Sat, 9 Jul 2011 14:46:23
> does not have magnitude but only direction.
Doubtful, but irrelevant to your argument. Which are you calling,
heads or tails.
>
>
>
> >> >Or did he exhaust himself leaning through those
> >> >turns conventionally?
>
> >> "conventionally" would be by countersteering - in fact there is no
> >> other way short of fitting trainer wheels or a sidecar.
>
> >Conventially means the lazyboy method of letting the bike drive
> >itself, no concious effort, no determined steering in the wrong
> >direction.
>
> Conscious (or as you put it, determined) countersteering is only an
> enhancement of what has to take place for a single track vehicle to
> steer at all.
The amount of counter steer is significant enough to consider it a
seperate method. Realisation of the method is not normally
automatic. The front tyre is steered hard, to move the contact
position of the front tyre outside the rear tyre in order to get the
bike to roll over the rear tyre. This steering initiation is
significant with criterium steering as the fork bend is short so the
sweep of the front wheel contact patch is relatively small. Only at
racing speeds do the forced turns appear an extension of the
automatically learned system. At speeds below 20mph, the forced turn
may require a counter steering displacement of 45deg. For only a
moment, but significant. If you blink, you could miss it.
>
>
>
> >> His problem was that he was trying to use bodyshift techniques
> >> /instead/ of proper (counter)steering.
>
> >If he'd have got it right and a little slower, the body movements
> >would work. Counter steering though is not a naturally learned skill
> >for the vast majority of riders. You of course are the exception.
>
> Along with almost every child who ever learned to ride a bicycle.
Then most children did not learn to ride a bicycle by your standards.
I certainly did not have any idea of the forced turn through my
childhood, it only became known to me after racing and after reading a
book on racing. The technique does not show up unless you are looking
for it. If you manage to scrub rubber from both tyres in a turn, it's
probably because you have correctly instigated a forced turn of
significant G force. If you havn't manged to do this and turn on a
sixpence, you probably still don't know what I'm on about.
>
>
>
> >> Bodyshifting is irrelevant and unnecessary until you are reaching the
> >> limit of ground clearance.
>
> >Wrong! Bodyshifting can get a rider out of trouble when he finds he
> >really is going too fast for a corner. It involves transferring all
> >weight to the outer pedal/peg and turning in the body to where the
> >rider wishes to go. It should get a cyclist about 3ft of roadspace
> >which wasn't there. I believe there is some effect with a motorbike,
> >but it is harder to assess and probably little more than a tyre's
> >width when riding a heavy motorbike.
>
> Watch any solo motorcycle racing and learn.
> Better yet, go to one of the motorcycle racing schools and find out
> the effect for yourself.
>
> You really think it magically gives the tyres more grip?
> I think you've lost yours.
> Soes this only happen if you have magic soldered wheels with loose
> spokes?
Well tracking wheels are important in maneuveurs which will tend to
scrub rubber.
> Not perfect, just realistic.
Realistically a child does not learn the forced turn technique, it is
completely alien to him. It is a technique learnt generally only for
racing and must be instructed (even by book).
thirty-six
> thirty-six <thirty-...@live.co.uk> considered Sat, 9 Jul 2011 14:29:04
> -0700 (PDT) the perfect time to write:
>
>
>
> >On Jul 9, 9:41 pm, Phil W Lee <p...@lee-family.me.uk> wrote:
> >> Winston <Wins...@BigBrother.net> considered Sat, 09 Jul 2011 12:03:34
> >> -0700 the perfect time to write:
>
> >> >One can move one's torso at the hips and lean without
> >> >benefit of handle bars. That is how most of us turn a
> >> >bicycle or motorcycle.
>
> >> That doesn't initiate a lean.
>
> >It does. I twist the saddle with my hips, the rear frame mo ves with
> >the saddle, the front steers in the opposite direction, the lean
> >develops in the direction the saddle was twisted and the bike rides an
> >arc in that direction until a further input at the saddle, in the
> >opposite direction, is used to end the turn.
>
> incidental lean that would normally be corrected to maintain a
> straight path.
Bullshit, I can steer around a road obstruction and return to my
position in short order with this technique. Most people I see do
have trouble and I guess it is due to cutaway saddles.
>
> >> Think of Newton's laws of motion.
>
> >> >One can merely lean into the turn as shown in the earlier video.
> >> >It is improper technique and dangerous in many situations,
> >> >but lots of us do it without any counter-steering.
>
> >> Where does the force come from?
>
> >My abdomen, through my hips.
>
> Pushing against what?
My mass, it is centred at around an inch below my navel, the procedure
is not difficult once the rider believes. Refusal to believe is
generally the only obstruction to its use.
> Do remember that every action has an equal and opposite reaction.
It doesn't matter how long you keep up this pointless and senseless
argument, you can't win.
>
>
>
>
>
> >> >It is possible to accomplish the most gradual turn by counter-steering.
> >> >Very gradual turns can be done safely by very moderate leaning, too.
> >> >I've done it both ways. They are fundamentally different.
>
> >> No, they are identical.
>
> >You don't understand! Ride no hands and think what you are doing to
> >steer around an obstruction in the road at about 12mph. Oh hold on,
> >you have an injury which possibly prevents normal operation. In which
> >case, stop arguing.
>
> See above.
You admit to arguing the toss rather than addressing the points in
hand or are you going to retreat to squirming yet again?
>
> >> >Kurt crossed the country by leaning.
> >> >Leaning isn't 'counter-steering'.
>
> >> No, but countersteering is the only way that the rider can initiate a
> >> lean.
>
> >This rider can initiate a lean by not only twisting his hips, with a
> >proper saddle (no cutaway) but also by simply applying more pressure
> >to one side of the bike or another, whether through the saddle by
> >rocking the pelvis or through the pedals. No handlebar contact is
> >required.
>
> See above.
I still call it heads.
Tºm Shermªn °_°
> On Jul 9, 10:27 pm, Winston<Wins...@BigBrother.net> wrote:
>> Tºm Shermªn °_°> wrote:
>>
>>> On 7/9/2011 2:03 PM, Winston wrote:
>>>> Peter Cole> "I think all cyclists counter-steer, most without knowing
>>>> it."
>>
>>>> If I'd made that assertion, I would have retracted it too. :)
>>>> Unicyclists are 'cyclists' too, yes?
>>
>> http://www.youtube.com/watch?v=UmkxGtOw1l4
>> He claims he leans to turn. He's really counter-steering,
>> without being aware of it too, yes?
>>
>>>> How do they counter-steer without benefit of a front wheel
>>>> to do it with?
>>
>>> Counter-steering does *not* work when cycling on a trike.
>>
>> It is also notoriously ineffective when driving a schoolbus
>> or a tractor or a jet plane or a rocket or a car or a truck
>> or many different kinds of vehicle.
>
> Er, actually quite useful when driving a recirulating ball steering
Now why would we want to do that, unless forced to drive a vehicle with
technology obsolete 50 years ago?
Tºm Shermªn °_°
> On Jul 10, 12:34 am, Phil W Lee<p...@lee-family.me.uk> wrote:
>> Do remember that every action has an equal and opposite reaction.
> It doesn't matter how long you keep up this pointless and senseless
Because Phil W. Lee (as the rest of us) has no experience riding on
Planet Trevor?
Winston
>> Kurt crossed the country by leaning.
>> Leaning isn't 'counter-steering'.
>>
> No, but countersteering is the only way that the rider can initiate a
> lean.
How many of Kurt's front tires were in contact
with the ground for most of his trip, including
turns? Answer: Zero.
How did Kurt counter-steer with only his rear
tire in contact with the ground?
Answer: He didn't. He shifted his system CG
towards the center of the intended turn.
He leaned.
--Winston
Winston
> Winston<Win...@BigBrother.net> considered Sat, 09 Jul 2011 10:13:11
> -0700 the perfect time to write:
>
>> Phil W Lee wrote:
>>> Winston<Win...@BigBrother.net> considered Fri, 08 Jul 2011 23:33:36
>>> -0700 the perfect time to write:
>>
>> (...)
>>
>>>> Unlike the unfortunates who crashed because they never learned
>>>> how to counter-steer.
>>>> http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
>>>>
>>> Just because people don't know they are doing it doesn't mean they
>>> aren't.
>>
>> I'm confused here, Phil. Help!
>>
>> In the video above, the rider that lost control of
>> his bike and unintentionally merged into the soft
>> shoulder had every reason to counter-steer.
>>
>> He 'bet the house' on his ability to get around
>> those mountain corners. Riders two seconds in front
>> of him made those corners safely, without waggling
>> their tailbones from port to starboard and back.
>>
>> Was he counter-steering? Really?
>
Yes. 'Some' counter-steering is more than 'zero'
counter - steering. Good.
>> Or did he exhaust himself leaning through those
>> turns conventionally?
>
> "conventionally" would be by countersteering -
No.
> in fact there is no
> other way short of fitting trainer wheels or a sidecar.
Leaning works.
> His problem was that he was trying to use bodyshift techniques
> /instead/ of proper (counter)steering.
We agree twice in one post! I'm gonna buy a lottery ticket!
> Bodyshifting is irrelevant and unnecessary until you are reaching the
> limit of ground clearance.
>>
>>> How do you think that any rider initiates "leaning into the turn"?
>>
>> Just as in the video I cited.
>>
>> Lean your torso in the direction of intended travel and
>> ease the bars *into* the turn. I did it that way
>> for too many years, though not as dramatically as we
>> see in the video.
>
> What were you pushing against to lean your torso?
I didn't have to push against anything.
I just leaned. Try it! It's fun!
Just now I leaned from side to side in my office
chair while listening to my noisy casters.
None of them budged, though there was a substantial
CG shift happening above the seat.
Shouldn't the office chair rocketed off in the
opposite direction due to this huge force?
Perhaps. It Just Didn't though.
>> That is fundamentally different from easing your bars
>> *out* of the turn and using the motorcycle's mass to
>> lean it into the intended direction.
>>
>> These are two different ways of turning.
>
> Yes, left and right.
>>
>> Smart riders use either technique as the
>> situation warrants. A long freeway sweep at [mumble]
>> miles per hour can be done very safely by moderately
>> leaning into the new direction while correcting the
>> bar position to establish a new equilibrium through
>> the turn, for example.
>>
>>> Think about Newton's laws of motion while you work it out.
>>
>> His first law from
>> http://teachertech.rice.edu/Participants/louviere/Newton/law1.html :
>>
>> "An object at rest will remain at rest unless acted on by an
>> unbalanced force. An object in motion continues in motion
>> with the same speed and in the same direction unless acted
>> upon by an unbalanced force."
>>
>> Moving the CG of the bike/rider system to the inside of
>> the turn is an excellent example of an 'unbalanced force'.
>
> So how do you move the CG?
> What sideways force do you apply to the mass of the rider and
> (motor)cycle except through the steering?
Leaning:
to incline, deviate, or bend from a vertical position.
>>
>> Sometimes that is the best way to turn your bike.
>> Sometimes it is just an unsafe maneuver.
>>
>> That is what I'm on about.
>>
>>
>> --Winston
>>
>>
>> If it means that just one new rider learns the
>> counter-steering technique as a result of this
>> otherwise baffling controversy, it will be well
>> worth the effort, IMVHO.
>
> Well, they can't ride if they don't already do it,
Nonsense. A majority of us ride without 'steering
left to go right' or vise - versa.
> but it is certainly
> worthwhile if they understand what they are doing.
> The video you posted of the snail's pace racer wannabe falling off is
> the proof of that.
He would have made the turn safely if he had
counter-steered around it.
--Winston
thirty-six
Some people still enjoy driving old vehicles from a time when
obsolecence had yet to attain a common recognition. They generally
ride easier.
thirty-six
$southslope.net"> wrote:
> On 7/9/2011 10:45 PM, thirty-six aka Trevor Jeffrey wrote:
>
> > On Jul 10, 12:34 am, Phil W Lee<p...@lee-family.me.uk> wrote:
> >> [...]
> >> Do remember that every action has an equal and opposite reaction.
> > It doesn't matter how long you keep up this pointless and senseless
> > argument, you can't win.[...]
>
> Because Phil W. Lee (as the rest of us) has no experience riding on
> Planet Trevor?
>
Because he is arguing whether it stands or hangs. I called heads.
James
How does anyone change direction on one wheel? Certainly not _only_
by leaning. You can't balance while stationary just by leaning. Try
it on a unicycle. Unicycle riders change direction by rotating the
upper body one way, which causes the lower body and unicycle to rotate
the other way - action and reaction pairs.
You think you can ride in a straight line, but you can not. A little
disturbance puts your CG to one side and you have to steer in that
direction to keep from falling. The bicycle is an inverted pendulum.
To make it turn left you subconsciously turn a little right first to
move your CG over to the left before you can turn that way.
--
JS.
Peter Cole
> Peter Cole wrote:
>> On 7/9/2011 2:33 AM, Winston wrote:
>
> (...)
>
>>> I misunderstand your terminology.
>>> Could you view this clip and tell me if this rider is
>>> turning conventionally or counter-steering, please?
>>>
>>> http://www.youtube.com/watch?v=SEDbWVor1b8
>>
>> Recumbent bicycles don't change the physics.
>
> Yes. At last we agree.
Not about steering, which is the subject under discussion.
>
> May I ask an entirely different question then?
>
> http://www.youtube.com/watch?v=SEDbWVor1b8
> Could you view this clip and tell me if this rider is
> turning conventionally or counter-steering, please?
As I've said, there is no difference.
>
>>> Maybe it is one of those 'perception' things, but
>>> I would swear that he is turning and leaning in
>>> the same direction, (into the turn, conventionally).
>>
>> At low speeds and gradual turns the amount of counter-steer is so small
>> it's hard to see.
>
> Did you detect the presence of any counter-steering
> at all in the video? I didn't.
See answer immediately above.
>
> Another fundamentally new question:
>
> Do you see any difference between the way he is
> turning and the way this rider is turning?:
> http://www.youtube.com/watch?v=C848R9xWrjc
> (Starting at ~2:36)
>
>>> I sure do.
>>
>> Counter-steering becomes more obvious during quick turns, but it's
>> really (it must be, according to physics) a continuum with ever more
>> being applied the more sudden the turn.
>
> For people who *do* counter-steer, that is true.
It is true for everyone, since everyone must counter-steer to ride a
bicycle.
>
>> Riding a bike is like balancing a broom on your palm. Most people can do
>> this without understanding the physics, and can even run and turn
>> corners while doing it. It's not difficult, nor does it require
>> intuition, counter or otherwise.
>
> In this second sentence and yesterday morning, you implied that counter-
> steering *is* understood intuitively.
>
> "Intuition (knowledge): understanding without apparent effort"
>
> Peter Cole > "I think all cyclists counter-steer, most without knowing it."
>
> If I'd made that assertion, I would have retracted it too. :)
You're now playing word games. I don't think most people (including you)
understand steering, yet they manage to do it anyway. Your problem is
that your attempt to understand steering doesn't agree with physics. It
is Newtonian physics which is counter-intuitive, which you are so
effectively demonstrating.
> Unicyclists are 'cyclists' too, yes?
>
> How do they counter-steer without benefit of a front wheel
> to do it with?
They have a single point of contact, they steer with an action/reaction
couple, as already been explained.
>
>>>>>> It's just a matter of conditioning the reflexes. Mountain biking does
>>>>>> this pretty quickly.
>>>>>
>>>>> I couldn't agree more (with this first sentence). :)
>>>>
>>>> When it comes to bike handling skills, mountain biking typically
>>>> provides far more frequent situations to develop those skills.
>>>
>>> In the same manner that being caged with a wild lion poses
>>> many more opportunities to develop one's lion taming skills
>>> than if one were to relax in front of the tube, for example?
>>
>> Probably more like learning to ski, an uneven slope will train necessary
>> balancing and coordination skills faster than a smooth one.
>
> Either way, I feel that it is proper to share a few words
> of advice and to show a demonstration of proper technique
> before loosing a new rider or skier into an unforgiving
> situation. I feel it is cruel to hold back those key facts
> that can mean the difference between a lifetime enjoying
> outdoor sports and a lifetime 'just surviving' with a serious
> injury.
Abrupt turning may require elevating technique from reflex to
consciousness for some people, I really don't know. I do know that, even
as a child, I was able to turn abruptly without particular difficulty --
without having been trained in counter-steering or Newtonian physics.
Since all bicycle turning requires the same technique, abrupt or not, it
may be that some people abandon learned reflexes when rare circumstance
requires a more abrupt turn, I couldn't really say, but I'm skeptical.
In any case, your description of "two types of steering" is probably
harmless, as it describes impression rather than physics, so while wrong
in a strict sense, perhaps is of some use to some people. I think it
would be more effective just to have inexperienced riders practice these
maneuvers, since it seems to be readily learned without exposure to
theory, or physics -- real or Wiley Coyote.
>>> > Since it's a matter of reflexive, not book, learning --
>>>
>>> The technique of turning the bars in the opposite direction
>>> of intended travel on purpose (counter steering) is, for
>>> most folks terra incognita.
>>
>> So you claim, but physics says that is not so.
>
> This guy is counter-steering then?
> http://media1.break.com/dnet/media/2007/10/15oct2-leaning-into-turn.jpg
>
> I am plagued by the feeling that we mean different things
> by the term 'counter-steering'.
I don't think so.
>
>>> We steer and lean 'into' our turns
>>> and for a vast majority of folks, that works just fine for the
>>> entire period spent on two wheels. There is nothing intuitive
>>> about counter-steering, IMVHO.
>>
>> To lean into a turn requires first steering in the opposite direction,
>
> One can move one's torso at the hips and lean without
> benefit of handle bars. That is how most of us turn a
> bicycle or motorcycle.
No, it isn't.
>
>> always, otherwise how do you initiate the lean? You can cock your upper
>> body one way in an attempt to lean, but that will just force your lower
>> body in the opposite direction.
>
> The net effect is to shift the center of gravity of the
> bike / rider system, initiating a normal turn in the
> same direction as the shift.
No shift. To understand this, you have to grasp the physics, which isn't
at all obvious to most people who haven't formally studied it.
>
> Climbing a rope ladder demonstrates this.
>
> The center of mass is *above* the fulcrum when
> climbing a rope ladder? Really?
>
> Advise less starch in your ropes. :)
I don't know what you mean by "fulcrum" in this context.
>
> (...)
>
>> I don't have any test subjects, I'm just summarizing current research.
>> Things like balance, timing, spacial perception, eye-hand coordination,
>> etc. can be improved with training, like endurance and strength. Also
>> like endurance and strength, they tend to decline with age. Focused
>> training can offset that to a significant degree.
>
> I understand and agree with the implications of 'brain plasticity'.
> That concept has stunningly little to do with the counter-steering
> technique.
My point was that abrupt steering, in that it may not arise in typical
cycling, may catch an inexperienced rider by surprise. In mountain
biking, circumstances that are at the limits of braking, slope, abrupt
turns and surface irregularities are much more common and so the
opportunities to improve the skills are also. Since these skills are
reflexive, not cognitive, you must learn by doing. Natural capacities
decline with age, but that can be compensated for (to an extent) with
training. While these are two separate incentives, they are linked via
the brain's ability to be reflexively trained, which continues
(apparently) at any age.
>
>>> Unlike the unfortunates who crashed because they never learned
>>> how to counter-steer.
>>> http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
>>>
>>
>> It's unlikely that that rider crashed from "not learning
>> counter-steering", since they all must have been counter-steering to
>> negotiate the twisty road they had been following for several miles.
>
> Most of them were. He was waggling his tailbone to drag his
> bike into the turns. Please review the video once again?
> (Particularly, sequences starting at 4:49, 5:43, 6:08, 6:26, 6:35 ..)
>
> His crash sequence starting at 7:51 is textbook 'non-counter-steer'.
> At 7:51 he should have been finessing his left handgrip away from
> his body instead of repeating his earlier 'leaning mistakes'.
> He ran out of road, panicked and Whoops! Into the dirt.
>
> That is an absolutely classic illustration of what happens.
> I hope he wasn't hurt.
>
>> In the video that shows the actual crash:
>> http://www.youtube.com/watch?v=sny83dnP4Kc&NR=1&feature=fvwp at 8:25, it
>> is impossible to determine the cause since the crashing rider has
>> already lost the line by the time he is in view of the following camera
>> rider. A poor example to make any point, or to identify the cause of the
>> crash.
>
> I agree. The video I cited earlier reveals the issue clearly.
Sorry, I didn't watch that one long enough to see the crash. Having now
done so, it looks to me like a typical crash, where the rider simply
misjudged the curve. When cornering like that, a cyclist or motorcyclist
must accurately estimate the amount of lean for the speed and radius of
curvature. If the rider underestimates the curve radius, it can be
difficult to correct either the speed or lean. If at the limit of
traction, braking may cause a skid, while increasing the lean requires
steering "out of" the curve momentarily, further eating up the limited
road width. Simply put, entering a curve too fast or at the wrong lean
angle can quickly run the rider out of options. It becomes a physics
problem with no solution. Our brains do these calculations, based
primarily on visual cues. Our ability to do this is remarkable, but not
infallible. It improves with practice.
>
>> Counter-steering must be performed to steer any bicycle or motorcycle
>> around curves,
>
> One can merely lean into the turn as shown in the earlier video.
> It is improper technique and dangerous in many situations,
> but lots of us do it without any counter-steering.
We all counter-steer to lean, there's no other way.
>
>> it's just not obvious unless the turn is abrupt. What you
>> call "counter-steering" is just abrupt turning, which uses the same
>> motions as gradual turning, only in a more exaggerated way.
>
> It is possible to accomplish the most gradual turn by counter-steering.
> Very gradual turns can be done safely by very moderate leaning, too.
> I've done it both ways. They are fundamentally different.
>
>> If you study the physics, you'll see it must be so.
>
> The physics disagree.
>
> http://www.youtube.com/watch?v=6yc9mmT62lQ
>
> Does Kurt counter-steer with his front wheel
> suspended in the air? What is the coefficient
> of friction of nitrogen? :)
The physics can't "disagree". A wheelie rider steers the same as a
unicycle rider. That question has already been answered.
>
>> You could come to the same
>> conclusion by riding a bicycle observantly.
>
> My observations result in the opposite conclusion.
>
>> Steering a bicycle is just creating a controlled rate fall in the
>> direction you want to go, counter-steering is the only way to initiate
>> that fall.
>
> Kurt crossed the country by leaning.
> Leaning isn't 'counter-steering'.
We all need to lean in turns, the question is how the lean is
controlled. It is different for 2-wheeled vehicles that 1-wheeled
vehicles. For 2-wheeled vehicles we counter-steer.
Peter Cole
> On Jul 9, 4:53 am, Peter Cole<peter_c...@verizon.net> wrote:
>> Steering a bicycle is just creating a controlled rate fall in the
>> direction you want to go, counter-steering is the only way to initiate
>> that fall.
>
> Good to "see" you again :-) Positive waves, man
I'm fine, thanks. My medical issues are resolved, at least for the time
being. I'm only prohibited from doing death marches, regular (whatever
that is) cycling is OK. I've just been very busy working on boats and
trailers -- in anticipation of actually doing some boating before our
lovely, but short, Boston summer is over. So may toys, so little time.
Not the worst of problems.
thirty-six
> thirty-six <thirty-...@live.co.uk> considered Sat, 9 Jul 2011 21:12:42
I'm not, I'm saying that the description "counter steering" is applied
specifically when a conscious effort is made to steer the wrong way
taking the front tyre contact area outside that of the rear wheel. If
not saying it doesn't happen at lesser levels, but the effects are
nowhere near as pronounced.
> You can see from that video that was posted (of the motorcycle crash)
> what happens when a rider fails to understand the mechanism at work
> and fights against it, instead of embracing it and using it.
> Lack of understanding does not change what happens, it just prevents a
> rider making proper use of it.
Exactly, he would need to have made a conscious effort to steer to
make the bike fall quick enough to make those turns correctly. He was
ignorant of the effect and ran out of road.
>
>
>
> >> >> Bodyshifting is irrelevant and unnecessary until you are reaching the
> >> >> limit of ground clearance.
>
> >> >Wrong! Bodyshifting can get a rider out of trouble when he finds he
> >> >really is going too fast for a corner. It involves transferring all
> >> >weight to the outer pedal/peg and turning in the body to where the
> >> >rider wishes to go. It should get a cyclist about 3ft of roadspace
> >> >which wasn't there. I believe there is some effect with a motorbike,
> >> >but it is harder to assess and probably little more than a tyre's
> >> >width when riding a heavy motorbike.
>
> >> Watch any solo motorcycle racing and learn.
> >> Better yet, go to one of the motorcycle racing schools and find out
> >> the effect for yourself.
>
> >> You really think it magically gives the tyres more grip?
> >> I think you've lost yours.
> >> Soes this only happen if you have magic soldered wheels with loose
> >> spokes?
>
> >Well tracking wheels are important in maneuveurs which will tend to
> >scrub rubber.
>
> I suppose you prefer solid tyres then - you wouldn't want to be
> disturbed by anything as normal as a slip angle.
I'm quite happy with the slip angles I experience with my tyres, they
permit steering without excessive tyre scrub and high cornering
forces.
> They usually don't learn it intellectually, but that they learn it
> physically is demonstrated by the fact they end up riding the bike.
>
> It really isn't rocket science.
> You want to stay on the bike, you steer into the fall.
That's the instruction I give to new riders. It seems to work well
enough with five minutes encouragement to leave them alone after that.
> You want to lean, you steer away from the desired lean until you are
> leaning enough to turn the desired amount, then you steer into the
> fall to arrest it.
Obviously lesson 2 after riding a relatively straight line, but you
fail to say why anyone would want to lean. I know, but how is it best
put across to a new rider?
>
> On a motorcycle this can be further complicated by hard acceleration
> (instead of arresting or reversing the lean by steering, you can do it
> by accelerating). but the levels of acceleration available on a pedal
> cycle are not sufficient for this to be a noticeable effect.
Winston
(...)
I saw an impossibility yesterday.
Guy was stock still at an intersection with
no feet on the ground, just balanced there
on two wheels.
Without any movement at all, how could he possibly
have remained vertical?
Is it a Miracle? :)
--Winston
thirty-six
> James wrote:
>
> (...)
>
> I saw an impossibility yesterday.
>
> Guy was stock still at an intersection with
> no feet on the ground, just balanced there
> on two wheels.
>
> Without any movement at all, how could he possibly
> have remained vertical?
Sky hooks.
Dan O
> On Jul 10, 4:22 pm, Winston <Wins...@BigBrother.net> wrote:
>
>
>
> > Phil W Lee wrote:
> > >> Kurt crossed the country by leaning.
> > >> Leaning isn't 'counter-steering'.
>
> > > No, but countersteering is the only way that the rider can initiate a
> > > lean.
>
> > How many of Kurt's front tires were in contact
> > with the ground for most of his trip, including
> > turns? Answer: Zero.
>
> > How did Kurt counter-steer with only his rear
> > tire in contact with the ground?
> > Answer: He didn't. He shifted his system CG
> > towards the center of the intended turn.
> > He leaned.
>
> How does anyone change direction on one wheel? Certainly not _only_
> by leaning.
Acceleration.
I've mentioned before the way motorcycle riders at Sidewinders
racetrack would come down the hill on their 750 Triumphs, into the
diminishing radius turn at the bottom, pitch it sideways, get on the
gas, pick up their foot, rear wheel hanging out and spinning, front
wheel floating in the air, and drive out of the turn onto the front
straight. Holy frickin' Moses! What just happened there? And the
feeling from the saddle? Words can't express it.
I hate to sound like I take anything on sheer faith. I appreciate
that the good mechanics / builders / tuners may have a closer grasp to
the physics, but I'm still sure they don't believe they have it all
figured out. I am willing to substantially accept that it just works
(TM), and do gain a sort of understanding from the saddle that I could
never get from equations.
Bicycles of course are quite, though not altogether, different, but I
do ride a bicycle out of my driveway on one wheel, weaving diagonally
between two cones, first left then right; then set down the front
wheel, cross the "bar" onto the road, lift the front wheel again, turn
90 degrees left, set it down again, and head on for the grocery
store. Not exactly sure how it all works. Too complex, really, to
even mess around trying to analyze completely (and no, Frank, that's
not just because I'm a simpleton). In the words of Bernie Taupin,
emanating from the Tumbleweed Connection LP recently appeared out of
nowhere in my living room right this very moment, "Just an old-
fashioned feelin', fully grown" :-)
<snip>
Tºm Shermªn °_°
Major effort to duplicate hominid locomotion:
<http://en.wikipedia.org/wiki/ASIMO>. No bicycle riding version, as of yet.
Frank Krygowski
>
> I think your test subjects self-select, then.
>
> Unlike the unfortunates who crashed because they never learned
> how to counter-steer.http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at...
>
I agree with almost everything you said; except I think the
motorcyclists in the last video didn't fall because of lack of
countersteering. It was lack of nerve.
A good friend of mine fell exactly that way on a motorcycle; I watched
it from behind. He was simply surprised by the sharpness of the
curve, and was afraid of leaning/turning sharply enough to stay on the
pavement. He "ran out of road," as they say.
- Frank Krygowski
Frank Krygowski
>
> How does anyone change direction on one wheel? Certainly not _only_
> by leaning. You can't balance while stationary just by leaning. Try
> it on a unicycle. Unicycle riders change direction by rotating the
> upper body one way, which causes the lower body and unicycle to rotate
> the other way - action and reaction pairs.
I've been away, and missed a lot of interesting discussion. Since
it's too tedious to reply to each one individually, I'm going to cover
several points here.
First, one cannot turn a one-track vehicle (bicycle or unicycle)
without somehow getting the center of gravity (CG) of the bike+rider
off vertical from the tire-to-ground contact patch, or the line
between two contact patches. With the CG to the right of the contact
patch, the rightward friction force on the tire at the contact patch
can cause the necessary acceleration to the right while retaining
balance.
But that's not necessarily "countersteering." And as a person who's
taught "instant turns" to dozens of people in cycling classes, I know
there are lots of people who do not, literally, countersteer to
initiate a turn.
What do I mean? I mean the term "countersteer" involves consciously
_steering_. And many cyclists don't really do that. As we all know, a
cyclist has to wobble a bit while going down a straight path. (I
believe many people initiate turns only by taking advantage of a
random wobble or lean in the proper direction. They're really not
capable of purposely initiating an instant turn. Instead of literally
"counterstering," they "counterwobble" into a turn.
If you take such a person and explain the physics properly (I use a
yardstick with a cardboard cutout biker silhouette for a class demo),
then do some live demos in a parking lot, most people will catch on
within five or six tries. I've had only a few student cyclists who
knew how to do this well before being taught; and I'm including people
who have ridden coast-to-coast and bike commuted for years.
What about just leaning to initiate a turn? What about unicycles, or
wheelie riders? I agree with James above; the trick involves rotation
about a _vertical_ axis. As he says, that twist of the hips causes
the upper body to rotate one way, the unicycle or wheelie cycle to
rotate the other way and thus countersteer. It's obviously trickier
than the usual counterwobbling. It's got to be deliberate, but it's
not obvious how it's done.
What about riding no-hands on a conventional bike? Does the rider
"just lean" to get around obstacles? I think it's more complicated.
As several have said, leaning one way with the upper body doesn't
shift the center of gravity of bike+rider, any more than (say) trying
to balance on a tightrope.* To push the CG (say) left, you'd have to
exert a force from the right, and at the CG there is no object or
influence to push that way.
But what does happen, I think, is that the rider leans one way, and
since the CG can't move, the bike leans the other way. Then comes the
critical phase: the front end geometry of head angle, fork rake, etc.
causes the fork to rotate in the necessary direction to steer the
contact patch toward the outside of the intended turn. Without that
important causal link, the trick wouldn't work. (And that, I think,
is what these Physics papers on bike stability are trying to
accurately quantify.)
And BTW, after re-watching that motorcycle crash video, I think that's
what the clumsy guy who crashed was trying to do. It worked up to a
point. But I now think it was the limitations of that technique,
rather than simple lack of nerve, that caused his crash.
What about track stands? Does a track stander just lean left and
right to keep CG over contact patch line? Nope - at least, not for
long. People with excellent balance reflexes can do it for a short
time while dead stationary; but most track standers do it standing
with handlebars cocked and the front wheel pointed slightly uphill.
Forward and backward motion (especially with a fixie) allow constant
lateral adjustment to keep the contact patch line directly under the
slightly shifting CG.
Again, as a person who's helped lots of people learn a quick turn, I
promise you that a good explanation and demo (i.e. coaching) really
helps. Yes, a child can do it. But as with swinging a bat, playing a
fiddle, or almost any other skill, improvement comes WAY faster with a
bit of knowledge, even if you have to get it your own out of a book.
Coaching is better yet.
*More on tightropes, and track stands: How does one balance, i.e.
keep their CG over a tightrope that's effectively an infinitely thin
line? It involves something that I think isn't very important to a
moving cyclist: Rotational inertia about the tightrope (or contact
patch line) axis. An ordinary klutz on a tightrope will start to tilt
right (i.e. rotate clockwise, as viewed from the back.) To counteract
this CW angular acceleration, he instinctively rotates his arms in
that CW direction. Since no torque can be applied at the tightrope,
this is his only way of applying a CCW reaction torque on his body and
stopping the main body rotation. But it's really difficult. A long
balance pole, especially with masses on each end, makes it way easier,
because it's got a tremendously higher rotational moment of inertia.
I think some track standers may do the same thing to a small degree,
which is the only way I know to keep balance while dead stopped. That
is, they rotate their upper body a bit about a horizontal fore-aft
axis. But I don't think it can contribute much, and it takes
excellent balance and reflexes.
For real-life riding, understanding and consciously using
countersteering can make you a much more nimble rider.
- Frank Krygowski
James
He was well balanced, but not perfectly. There would have been some
small movement, particularly when a disturbance input (gust of wind)
took him off balance. I can track stand too and barely rock fore and
aft on a good day. Some can do it sitting down. Some can do it no hands.
Really, the inverted pendulum control theory is not that difficult to
understand or implement with control theory and some hardware. The
human control box is quite capable of doing the same or better.
http://en.wikipedia.org/wiki/Inverted_pendulum
Like balancing a broom on your hand, as someone else mentioned earlier.
--
JS.
James
Do you move your knees in and out or rotate the handlebars in the air
while on one wheel to help maintain balance?
http://www.freewebs.com/cyclingfreak/Mcewen.jpg
http://2.bp.blogspot.com/_LG5wULbDumE/TQLRfzhUfOI/AAAAAAAAAlY/AA14jeMp2fc/s1600/wheelie+Robbie.jpg
http://3.bp.blogspot.com/__kXtHY3SVww/TRmMJg4btwI/AAAAAAAAATw/EljZp5Ccm4g/s1600/_41812386_mcewen.jpg
http://i6.photobucket.com/albums/y224/velocidad/McEwenWheelieTdF04.jpg
--
JS.
carlgr...@gmail.com
> On Jul 10, 4:27 am, James <james.e.stew...@gmail.com> wrote:
[snip]
> What about track stands? Does a track stander just lean left and
> right to keep CG over contact patch line? Nope - at least, not for
> long. People with excellent balance reflexes can do it for a short
> time while dead stationary; but most track standers do it standing
> with handlebars cocked and the front wheel pointed slightly uphill.
> Forward and backward motion (especially with a fixie) allow constant
> lateral adjustment to keep the contact patch line directly under the
> slightly shifting CG.
[snip]
> *More on tightropes, and track stands: How does one balance, i.e.
> keep their CG over a tightrope that's effectively an infinitely thin
> line? It involves something that I think isn't very important to a
> moving cyclist: Rotational inertia about the tightrope (or contact
> patch line) axis. An ordinary klutz on a tightrope will start to tilt
> right (i.e. rotate clockwise, as viewed from the back.) To counteract
> this CW angular acceleration, he instinctively rotates his arms in
> that CW direction. Since no torque can be applied at the tightrope,
> this is his only way of applying a CCW reaction torque on his body and
> stopping the main body rotation. But it's really difficult. A long
> balance pole, especially with masses on each end, makes it way easier,
> because it's got a tremendously higher rotational moment of inertia.
>
> I think some track standers may do the same thing to a small degree,
> which is the only way I know to keep balance while dead stopped. That
> is, they rotate their upper body a bit about a horizontal fore-aft
> axis. But I don't think it can contribute much, and it takes
> excellent balance and reflexes.
Dear Frank,
Bah! Who needs a front wheel cocked uphill?
Even a little girl can do one-foot no-hands unicycle trackstands while
putting the dishes away:
http://www.youtube.com/watch?v=XIECdLtVTwA&feature=related
Of course, her tall-bike unicycle's polar moment of inertia helps.
Cheers,
Carl Fogel
Frank Krygowski
wrote:
>
>
> Even a little girl can do one-foot no-hands unicycle trackstands while
> putting the dishes away:
>
> http://www.youtube.com/watch?v=XIECdLtVTwA&feature=related
Bet she couldn't do that until she read our discussion here. ;-)
> Of course, her tall-bike unicycle's polar moment of inertia helps.
Yes, really! Anyone who's ridden an "ordinary" (or I suppose, a tall
bike) knows how much easier they are to balance.
- Frank Krygowski
Winston
Fatigue does that.
The first part of that video shows our rider exerting
an amazingly high amount of effort to get around those
mountain curves. No counter-steering at all, just
waggling his torso and dragging the bike into the
turns. See the way he uses the entire road instead
of staying in the half-lane like the preceding
riders did?
Had he counter-steered through those turns, he
would still have been thinking clearly enough to
deal safely with the turn that 'got him'.
He ran out of road at 7:51.
http://www.youtube.com/watch?v=leBMUKAp5Yc&feature=player_embedded#at=527
That was a completely avoidable crash.
Here is hoping that more riders learn the technique
very well *before* heading into the hills.
--Winston
James
I agree. By tilting the frame of the bicycle off vertical (say to the
left), the steering geometry will "flop" the front wheel in that
direction. The CG then is pushed to the right as the bicycle is now
steering to the left away from a balance point, so the rider must
correct the steering by tilting the frame right to get the front wheel
to "flop" right and turn a corner in that direction.
> And BTW, after re-watching that motorcycle crash video, I think that's
> what the clumsy guy who crashed was trying to do. It worked up to a
> point. But I now think it was the limitations of that technique,
> rather than simple lack of nerve, that caused his crash.
>
> What about track stands? Does a track stander just lean left and
> right to keep CG over contact patch line? Nope - at least, not for
> long. People with excellent balance reflexes can do it for a short
> time while dead stationary; but most track standers do it standing
> with handlebars cocked and the front wheel pointed slightly uphill.
> Forward and backward motion (especially with a fixie) allow constant
> lateral adjustment to keep the contact patch line directly under the
> slightly shifting CG.
So how do you do a track stand with a freehub pointing down hill?
Simple, you roll a bit forward, lock the front brake and push back off
it and release the brake just after. You then effectively pull the bike
backward up hill a little with your bodies momentum.
Track stands are best practiced on smooth pavement with a slight uphill
tilt, as it makes the reversing part much easier to begin with.
Indeed it is very useful to avoid surprise obstacles in your path.
Another thing, most high speed cornering experts tell you to look where
you want to go. If you don't look for the exit of a tight corner, and
focus on the mountain side or ravine, that is where you end up heading.
--
JS.
Winston
> Frank Krygowski wrote:
(...)
>> For real-life riding, understanding and consciously using
>> countersteering can make you a much more nimble rider.
>
> Indeed it is very useful to avoid surprise obstacles in your path.
>
> Another thing, most high speed cornering experts tell you to look where
> you want to go. If you don't look for the exit of a tight corner, and
> focus on the mountain side or ravine, that is where you end up heading.
Thanks, Frank and James.
--Winston
Tºm Shermªn °_°
A very low bicycle is the easiest to balance with both feet clipped in -
just put a hand on the ground. :)
Michael Press
James <james.e...@gmail.com> wrote:
Also see parametric resonance.
<http://en.wikipedia.org/wiki/Parametric_oscillator#Parametric_resonance>
--
Michael Press
Dan O
> James wrote:
> > Frank Krygowski wrote:
>
> (...)
>
> >> For real-life riding, understanding and consciously using
> >> countersteering can make you a much more nimble rider.
I don't know. Relying on consious response sounds relatively clumsy
to me. A predominantly unconscious response - combined with conscious
thought, planning and control - seems more optimum to me.
(But we know of my "unique opinions" :-)
>
> > Indeed it is very useful to avoid surprise obstacles in your path.
>
(see above)
> > Another thing, most high speed cornering experts tell you to look where
> > you want to go. If you don't look for the exit of a tight corner, and
> > focus on the mountain side or ravine, that is where you end up heading.
Well, yeah, there is certainly that target fixation thing, but I don't
think you have to consciously focus on your line; it just has to be
the overriding intent of your being. (Ooooooo - Dan is really getting
out there somewhere. Time to knock it off again for a while.
Cheers!)
>
> Thanks, Frank and James.
>
Dan O
Handlebars / front fork and wheel.
Dan O
A friend of mine (I think I've told this story here before) fell on
his motorcycle. I watched it from behind. Leaned over so far the
handlebar was almost touching the ground, he got way out of the groove
and into the marbles. Then the bike was on its side with his butt
skdding across the ground. But he hung onto the bars, got the tires
back on the dirt before he got to the haybales, picked the thing up,
took off again without ever stopping, and I never even passed him.
(I don't think he learned how to do that in a book or a training
course.)
Dan O
> Dan O <danover...@gmail.com> considered Mon, 11 Jul 2011 12:24:55
> -0700 (PDT) the perfect time to write:
>
> >> James wrote:
> >> > Frank Krygowski wrote:
>
> >> (...)
>
> >> >> For real-life riding, understanding and consciously using
> >> >> countersteering can make you a much more nimble rider.
>
> >I don't know. Relying on consious response sounds relatively clumsy
> >to me. A predominantly unconscious response - combined with conscious
> >thought, planning and control - seems more optimum to me.
>
> >(But we know of my "unique opinions" :-)
>
> responses are in harmony, rather than in conflict.
>
I can attest to that.
thirty-six
> Surely the important thing is that the conscious and unconscious
> responses are in harmony, rather than in conflict.
>
Let your dreams guide you to a happy life.
Tºm Shermªn °_°
> Dan O<danov...@gmail.com> considered Mon, 11 Jul 2011 12:24:55
> -0700 (PDT) the perfect time to write:
>
>>> >> James wrote:
>>>> >> > Frank Krygowski wrote:
>>> >>
>>> >> (...)
>>> >>
>>>>> >> >> For real-life riding, understanding and consciously using
>>>>> >> >> countersteering can make you a much more nimble rider.
>> >
>> >I don't know. Relying on consious response sounds relatively clumsy
>> >to me. A predominantly unconscious response - combined with conscious
>> >thought, planning and control - seems more optimum to me.
>> >
>> >(But we know of my "unique opinions":-)
Good reason to practice to build "muscle memory".
thirty-six
> > -0700 (PDT) the perfect time to write:
>
> >> >On Jul 10, 9:27 pm, Winston<Wins...@BigBrother.net> wrote:
> >>> >> James wrote:
> >>>> >> > Frank Krygowski wrote:
>
> >>> >> (...)
>
> >>>>> >> >> For real-life riding, understanding and consciously using
> >>>>> >> >> countersteering can make you a much more nimble rider.
>
> >> >I don't know. Relying on consious response sounds relatively clumsy
> >> >to me. A predominantly unconscious response - combined with conscious
> >> >thought, planning and control - seems more optimum to me.
>
> >> >(But we know of my "unique opinions":-)
> > Surely the important thing is that the conscious and unconscious
> > responses are in harmony, rather than in conflict.[...]
>
> Good reason to practice to build "muscle memory".
>
Oh fuck, you feel your way around corners, you must be wearing dark
glasses? Your postings are such a beautifully coherent muddle.
Peter Cole
> On Jul 10, 4:27 am, James<james.e.stew...@gmail.com> wrote:
>>
>> How does anyone change direction on one wheel? Certainly not _only_
>> by leaning. You can't balance while stationary just by leaning. Try
>> it on a unicycle. Unicycle riders change direction by rotating the
>> upper body one way, which causes the lower body and unicycle to rotate
>> the other way - action and reaction pairs.
>
> I've been away, and missed a lot of interesting discussion. Since
> it's too tedious to reply to each one individually, I'm going to cover
> several points here.
>
> First, one cannot turn a one-track vehicle (bicycle or unicycle)
> without somehow getting the center of gravity (CG) of the bike+rider
> off vertical from the tire-to-ground contact patch, or the line
> between two contact patches. With the CG to the right of the contact
> patch, the rightward friction force on the tire at the contact patch
> can cause the necessary acceleration to the right while retaining
> balance.
>
> But that's not necessarily "countersteering."
Yes, it is. It is the very definition of counter-steering.
> And as a person who's
> taught "instant turns" to dozens of people in cycling classes, I know
> there are lots of people who do not, literally, countersteer to
> initiate a turn.
Everyone counter-steers to turn. They may be unaware of that, but they
still do. Abrupt turns require abrupt counter-steer movements. I think
what you see among the inexperienced is a failure of untrained reflexes
in abrupt turn situations. I'm sure that people would develop these
reflexes if they encountered the need for abrupt turns regularly. We
did, even as children.
> What do I mean? I mean the term "countersteer" involves consciously
> _steering_. And many cyclists don't really do that. As we all know, a
> cyclist has to wobble a bit while going down a straight path. (I
> believe many people initiate turns only by taking advantage of a
> random wobble or lean in the proper direction. They're really not
> capable of purposely initiating an instant turn. Instead of literally
> "counterstering," they "counterwobble" into a turn.
I think you have an over-active imagination.
> If you take such a person and explain the physics properly (I use a
> yardstick with a cardboard cutout biker silhouette for a class demo),
> then do some live demos in a parking lot, most people will catch on
> within five or six tries. I've had only a few student cyclists who
> knew how to do this well before being taught; and I'm including people
> who have ridden coast-to-coast and bike commuted for years.
Abrupt turns are simply often not in a rider's repertoire simply because
the need is so infrequent. People are also bad at handling rear wheel
skids. When I first started mountain biking, I fell at almost every
slippery log -- it was simply not a situation that I encountered with
enough frequency to master. After a while, I stopped falling that way.
No explanations of theory or exotic techniques were needed, my reflexive
brain just needed training.
> What about just leaning to initiate a turn? What about unicycles, or
> wheelie riders? I agree with James above; the trick involves rotation
> about a _vertical_ axis. As he says, that twist of the hips causes
> the upper body to rotate one way, the unicycle or wheelie cycle to
> rotate the other way and thus countersteer. It's obviously trickier
> than the usual counterwobbling. It's got to be deliberate, but it's
> not obvious how it's done.
Seems pretty obvious to me. Conservation of momentum dictates that
rotating the upper body causes a counter-rotation of the lower. When the
upper is rotated back, the lower stops rotating. The body is at rest,
but the angle has been changed. The reason the lower body doesn't return
to its original position is stiction (non-linear friction).
> What about riding no-hands on a conventional bike? Does the rider
> "just lean" to get around obstacles? I think it's more complicated.
> As several have said, leaning one way with the upper body doesn't
> shift the center of gravity of bike+rider, any more than (say) trying
> to balance on a tightrope.* To push the CG (say) left, you'd have to
> exert a force from the right, and at the CG there is no object or
> influence to push that way.
>
> But what does happen, I think, is that the rider leans one way, and
> since the CG can't move, the bike leans the other way. Then comes the
> critical phase: the front end geometry of head angle, fork rake, etc.
> causes the fork to rotate in the necessary direction to steer the
> contact patch toward the outside of the intended turn. Without that
> important causal link, the trick wouldn't work. (And that, I think,
> is what these Physics papers on bike stability are trying to
> accurately quantify.)
You can "flop-steer" a bicycle just because of steering trail. We do
this all the time when walking a bicycle while holding the saddle.
Tilting the bike causes the front wheel to steer in the direction of tilt.
Bikes become much more easy to ride no-handed with increasing speed. The
flop mechanism doesn't change effectiveness with speed, but the
gyroscopic mechanism does. It causes the same tilt-to-steer coupling,
but it is rate sensitive in two ways. First, the faster the wheel spins,
the larger the angular momentum and the more pronounced the gyroscopic
effect. Second, the faster the bike is tilted, the more force is applied
in the turning direction. The way to ride a bike no-hands at typical
speeds is to "flick" your hips quickly with relatively small motions.
> And BTW, after re-watching that motorcycle crash video, I think that's
> what the clumsy guy who crashed was trying to do. It worked up to a
> point. But I now think it was the limitations of that technique,
> rather than simple lack of nerve, that caused his crash.
He simply picked the wrong line, took the curve too fast, or both. The
velocity of the rider and the radius of the curve set the acceleration,
which is driven by the centripetal force, which is provided at the
contact patch. To maintain (roll) balance, the rider must perfectly
balance gravity and centripetal force, else an acceleration in the roll
direction will be induced. If the rider counter-steers in mid-curve to
set a more pronounced lean angle, he must momentarily steer out of the
turn (increase turn radius). The consequence of that is that, because of
the additional road width he has "consumed" the required radius to
negotiate the remainder of the curve becomes smaller -- you quickly
reach the point of diminishing returns, and the situation becomes
unrecoverable.
My guess is that the crashed rider followed the leaders and merely
matched speeds and lines with them. At the time of the crash a gap
seemed to have opened between them, probably motivating him to go faster
while at the same time eliminating his guide.
People gratuitously wiggle on bicycles and motorcycles while turning,
but it has little effect. It's the radius of turn you're trying to
control, moving mass one way above the center only reacts the mass
below, the momentum is unaffected. The limit example is probably those
stunt riders who drive a car on two wheels around a course, all the hip
waggling in the world isn't going to do a thing. It's all counter-steer,
it must be.
A body at rest stays at rest. What the balance pole does is slow things
down enough for the walker to counter-drive the oscillations. Any child
can pump a swing to go higher and higher, most could equally
counter-pump to damp the oscillation.
> I think some track standers may do the same thing to a small degree,
> which is the only way I know to keep balance while dead stopped. That
> is, they rotate their upper body a bit about a horizontal fore-aft
> axis. But I don't think it can contribute much, and it takes
> excellent balance and reflexes.
If you start still, then you'll stay still, except for oscillations, The
problem of balance is mostly actively damping oscillations. There is
often some small friction that can be exploited.
> For real-life riding, understanding and consciously using
> countersteering can make you a much more nimble rider.
Consciousness doesn't improve anything except for the curious. Reflexes
need to be trained, that's all. All bike steering is counter-steering.
The only thing that varies is the degree, not the principle. The way to
learn to turn abruptly is to practice abrupt turns.
thirty-six
>
> If you start still, then you'll stay still, except for oscillations, The
> problem of balance is mostly actively damping oscillations. There is
> often some small friction that can be exploited.
Stronglight A9 headsets are good for that. It also helps one learn
to make positive steering inputs to initiate turns, it was probably
essential in helping me understand the mechanism of steering no-hands,
that of twisting the rear frame using my hips, although rocking the
hips also affects steering at a slower rate.
>
> > For real-life riding, understanding and consciously using
> > countersteering can make you a much more nimble rider.
>
> Consciousness doesn't improve anything except for the curious. Reflexes
> need to be trained, that's all. All bike steering is counter-steering.
> The only thing that varies is the degree, not the principle. The way to
> learn to turn abruptly is to practice abrupt turns.
Hey hey, let's leave it at that.