200mph shimmy, or what makes a bike stay up
Erik
"R. Himm" <no...@none.none> wrote in message
news:none-ya02358000...@news.microtec.net...
>
> Periodically here there are some arguments about what makes a bike stay
up.
> Some say the rider balances it; others say gyroscopic action of the
wheels.
>
> Obviously in a track stand it's all balance, and as the speed gets higher,
> gyroscopic effects begin and increase. I saw an illustration of this today
> on RealTV (don't know whether it was a rerun or not), which of course I
> never watch but just happened to catch.
>
>
> Some good old boy was trying to set a new land speed record for
> motorcycles. The current record, which he holds, was about 195 mph, while
> his goal was to break 200. On the first run, as he got up to 200mph, an
> amazing shimmy began to develop. At that speed on a heavy motorcycle, it's
> quite a sight to see. The good old boy's reaction was to take his hands
off
> the handlebars. Naturally that didn't seem to reduce the shimmy much...
but
> it did succeed in throwing him off the bike. Only, one of his legs was
> somehow caught in the frame. Naturally the shimmy eased off... small
> comfort as the guy was bounced and dragged along by the bike at nearly
> 200mph. This went on for some while, the bike staying up and riding in a
> straight line, until finally the rider shook himself free... and the bike
> continued on riderless, at extreme speed, still in a perfect straight
line,
> on and on and on and on. Doubtful the rider's balancing act, half a mile
> behind as he skidded on and on with his remaining momentum, had much to do
> with it.
>
>
> The rider was shaken up but no more damaged than in his original state, so
> once the bike ran out of steam and was retrieved, he set up for a second
> attempt. "We all fixied up the soospenshun up fronnt, dat otta takey care
> of any bumps this time...." or something like that. Away he went... and
> naturally the shimmy started up again as the critical speed was reached.
> Only this time, it became catastrophic nearly immediately, and he got
> thrown completely clear as the bike shook itself to pieces, and seemingly
> or perhaps really, exploded.
>
> I didn't quite catch it, but it seemed as if on this run he actually was
> able to break the record, as well as his bike and his leg.
the balance of the wheels or precision of the hub
bearings, or most likely combination of the both was not up
to the speed gained. resonance would be the keyword here...
erik
Tim McNamara
<no...@none.none> wrote:
> Periodically here there are some arguments about what makes a bike stay up.
> Some say the rider balances it; others say gyroscopic action of the wheels.
>
> Obviously in a track stand it's all balance, and as the speed gets higher,
> gyroscopic effects begin and increase.
Gyroscopic effects are not what makes a bicycle remain upright. The
issue is the steering geometry- a bicycle can be designed with steering
geometry that makes it impossible to ride, or with geometry that will
allow it to coast riderless for long distances.
See F.W. Rowland and D.C. Wilson, _Bicycling Science_, pp. 215-235 and
C.E.F. Jones, 1970, The stability of the bicycle, _Physics Today_
(April 1970), 34-40.
Noel Llopis
<010920010949338010%tim...@mac.com>:
>Gyroscopic effects are not what makes a bicycle remain upright. The
>issue is the steering geometry- a bicycle can be designed with steering
>geometry that makes it impossible to ride, or with geometry that will
>allow it to coast riderless for long distances.
So if a bike instead of wheels had magical anti-gravity
pads to keep it off the ground, you would still be able to
ride it? I thought the gyroscopic effect of the rotating
wheels was the key element to stay upright. I'm not saying
that it is, I'm just surprised that my intuition was completely
wrong.
--Noel
jobst....@stanfordalumni.org
>> Gyroscopic effects are not what makes a bicycle remain upright.
>> The issue is the steering geometry- a bicycle can be designed with
>> steering geometry that makes it impossible to ride, or with
>> geometry that will allow it to coast riderless for long distances.
> So if a bike instead of wheels had magical anti-gravity pads to keep
> it off the ground, you would still be able to ride it? I thought the
> gyroscopic effect of the rotating wheels was the key element to stay
> upright. I'm not saying that it is, I'm just surprised that my
> intuition was completely wrong.
Your anti-gravity bicycle has no contact with the ground and cannot
corner, and is therefore, not a practical model to assess bicycle
stability. You might read the FAQ item on this which was distilled
from many discussions about the subject:
http://draco.acs.uci.edu/rbfaq/FAQ/188.html
Jobst Brandt <jobst....@stanfordalumni.org>
Tim McNamara
<no...@none.none> wrote:
> Yeah, I know about the trick bikes, and the difference in stability offered
> by various geometries, but I think you missed the point of the post,
> perhaps my fault. As speed increases, so too does the gyro effect. If the
> bike is designed with good steerign geometry, so that the forces generated
> in the application of the gyro effect are not destructive to keeping the
> front wheel up/in line, eventually, e.g. at 200mph on a heavy motorcycle
> wheel, it must contribute significantly to the stability, i.e. apart from
> the rider's ability to balance the bike, and why not quite a while before
> that... Also, this motorcycle was not coasting riderless for a long
> distance, it was powered riderless for a long distance.
And this has what to do with bicycles?
> Maybe a better way to explain what I'm getting at is, bikes with good
> steering geometry will not coast riderless for long (i.e. commensurate with
> their momentums versus the rolling resistance, wind resistance and bearing
> friction, i.e. the same amount as if they had four non-steerign wheels)
> distances at very low speeds, and certainly not in the face of
> destabilizing forces like the rider being dragged and bounced along the
> ground by one leg stuck in the frame.
What applies to a several hundred pound motorcycle at 200 mph in terms
of gyroscopic forces is irrelevant to a 25 lb bicycle at 30 mph. The
causes of shimmy are different as well. Read the r.b.t. FAQ on shimmy.
There are too many extraneous factors that could have contributed to
the catastrophe you describe, including surface irregularities, wind
buffeting, rider stupidity, something broken in the frame or suspension
(say, a motor mount tearing away from the frame), failure to properly
tune the spring rate and especially the damping in the suspension, etc.
Motorcycles used for these purposes tend to have steering geometry with
a very slack head angle and a large amount of trail; they are so stable
that they are pretty much unrideable in anything other than a straight
line.
Tim McNamara
<llo...@home.com.xxx> wrote:
It's a common misconception, gained in part from holding a spinning
wheel by the axles and feeling the gyroscopic resistance to moving it,
and in part from people telling us that's what keeps a bike upright.
Tests that are designed to counter the gyroscopic force demonstrate
that the bike doesn't ride differently with these forces cancelled out.
The key factor is a geometric property called trail (I'm sure there's
diagrams and everything at www.sheldonbrown.com) which is what enables
the bike to self-center ist steering. We stay upright by steering the
bike under whichever side we are falling towards, in tiny increments.
Watch a child learn to ride and you will see these corrections very
clearly. As their skill develops, the corrections become smaller and
smaller until they are practically invisible.
jobst....@stanfordalumni.org
> Jone's paper was so long ago that I think people who cite it often
> only remember the fact that he could ride the anti-gyro stuff, not
> what he actually said about riding it. Or perhaps they haven't read
> the paper to begin with.
> See above. Obviously there are several factors at work in the
> stability of a bicycle. As speed changes the relative importance of
> them changes. At the extreme, one has the nice example that I
> detailed in the first post, although it isn't pedal
> powered. Yeesh. Maybe you just had to have seen the clip.
That the paper was a long time ago is not what irks me about the
publication but rather that he didn't go to the heart of the matter by
citing scooters with wheels as small as roller skates (that have no
practical gyroscopic forces even at 200mph) and beyond that scooters
with ice skates for wheels. For that matter, ice skates remain
upright the same way.
His whole search for the bicycle that "can't be ridden" was stupid
because we have seen circus performers ride anything that has at least
one wheel, even disassembling a bicycle while balancing on the front
wheel... until there is nothing left but the wheel. Where do these
people grow up with such dull lives, not to have seen the great
circuses of the world?
So that "obviously there are several factors at work in the stability
of a bicycle" NOT. Riding no hands is, as I state in the FAQ, a force
so faint that most riders cannot detect it to make use of it and has
nothing to do with their bicycling in the first place, although it
does for mine because I often ride no-hands.
>> The causes of shimmy are different as well. Read the r.b.t. FAQ on
>> shimmy.
They are not.
> Yeah, I know about that too. In fact maybe you should reread that too:
# Shimmy is caused by the gyroscopic force of the front wheel that acts
# at 90 degrees to the axis of the steering motion. The wheel steers to
# the left about a vertical axis when it is leaned to the left about a
# horizontal axis. When the wheel leans to the one side, gyroscopic
# force steers it toward that side, however, the steering action
# immediately reverses the lean of the wheel as the tire contact point
# acts on the trail of the fork caster to reverse the steering motion.
# The shimmy oscillates at a rate that the rider's mass on the saddle
# cannot follow, causing the top and down tubes to act as springs that
# store the energy that initiates the return swing. The shimmy will
# stop if the rider unloads the saddle, because the mass of the rider is
# the anchor about which the oscillation operates. Without this anchor
# no energy is stored. The fork and wheels may store some energy,
# although it appears the frame acts as the principal spring.
> There is nothing here to differentiate this mechanism from what
> happens in a motorcycle. Although there are not precisely top and
> down tubes in a motorcycle, there is still plenty to act as a
> spring. It certainly explains very well why the shimmy didn't stop
> when he removed his hands from the bars, but did when he was removed
> from the saddle. By the way this explanation, likewise the FAQ on
> what makes a bike stay up, also conflict with your first claim up
> above.
The bicycle stays up for the reasons described in the FAQ, nothing more.
Jobst Brandt <jobst....@stanfordalumni.org>
jobst....@stanfordalumni.org
>> So that "obviously there are several factors at work in the stability
>> of a bicycle" NOT. Riding no hands is, as I state in the FAQ, a force
>> so faint that most riders cannot detect it to make use of it and has
>> nothing to do with their bicycling in the first place, although it
>> does for mine because I often ride no-hands.
> It seems to me that the first sentence and the last phrase of this
> paragraph are in contradiction.
The force is so slight that most riders cannot sense it and therefore
cannot make use of it to ride no-hands. That's pretty straight
forward English.
> This may be a misunderstanding of your point on my part: I'm not
> sure why you say the force is so faint few people can detect it to
> make use of it- is this meant to imply that few people are able to
> ride a bike with no hands? Maybe life is different round your way
> but here every yotz with a bike no matter what type is riding no
> hands in traffic, carrying a six pack of beer.
I'm talking about the folks who write here on wreck.bike. We have had
surveys and i often ask riders whose bicycles have wheels askew
whether the bicycle rides straight no-hands. The answer is invariably
in disbelief that I would even suggest such a dangerous act, followed
by "I never ride no-hands."
> Some are weaving and a few are riding straight, but there they all
> are. Well, really I've never met anyone who doesn't ride no hands,
> and see it all the time on the streets amongst the hoi polloi. And
> while I agree the force is a little faint a low speeds I certainly
> find it strong when riding no hands at moderate speed downhill.
Maybe you could describe what sort of riders these are. We don't have
those around here. USCF Category racers mostly master the act but
then they usually don't post on wreck.bike.tech/misc
> Well, that's neither here nor there I suppose. More to the point:
>> So that "obviously there are several factors at work in the
>> stability of a bicycle" NOT.
>> The bicycle stays up for the reasons described in the FAQ, nothing more.
> As a clarification, what I was saying conflicts with mMacnamara's claim is,
> he said the handling of a bike with no gyro was identical to that of an
> ordinary bike. On the contrary-
I'm not interested in parsing other peoples perception of bicycle
stability in minutia. The basic facts are as stated. If you can show
otherwise, pleas do.
Jobst Brandt <jobst....@stanfordalumni.org>
Jon Isaacs
>surveys and i often ask riders whose bicycles have wheels askew
>whether the bicycle rides straight no-hands. The answer is invariably
>in disbelief that I would even suggest such a dangerous act, followed
>by "I never ride no-hands."
As one of those who often says "i never ride no-hands" I think a bit of
clarification is in order here.
This does not mean I am unable to ride no hands, I have been able to do so for
close to 50 years.
Rather it is simply that I choose to ride with at least one hand on the bars at
all times.
In my experience most riders who have an interest in riding no-hands can do so,
it is really not much of a skill IMHO.
However in my personal experience, riding with no hands leaves one vulnerable
to unseen road debris and road damage. This is one lesson I learned the hard
way, I have the bad knee to remind me and I do not intend to repeat my previous
mistake. There is little to gain and much to lose.
Jon Isaacs
V T Bridge
up so that the front wheel, because of the weight on it, turns the right
amount in the right direction to more-or-less maintain system balance. That
balance is tuned to be tenuous enough that the rider can disturb it easily
enough to have a responsive vehicle (or not, if that's what the designer was
aiming at).
Gyroscopic forces are always present. On a bike, the wheel is light enough
and the speeds low enough that the weight-and-geometry forces always
predominate. On a motorcycle, with much heavier mheels, that's not so. On my
old RD-350, below 12-15 mph, if you wanted to turn left I cranked the bars
left, and it steered sike a truck. Above that speed, to turn left I torqued
the bars *right*. The resulting gyroscopic force leaned the cycle to the
left, and then the weight-and-geometry caused the wheel to take up the
slight angle to the left required for the turn.
This all happens so intuitively that I'd ridden the cycle for a year before
I realized it, and only noticed because I was taking a course in mechanics
and was looking for the effect.
Re the anti-gravity pads, tire traction is a critical component of system
stability, as anyone who's hit a patch of gravel in a turn knows too well.
If your anti-gravity gear doesn't provide some equivalent to it, I suggest
you find another supplier.
Noel Llopis wrote in message ...
Tim McNamara
<flipfl...@yahoo.ca> wrote:
> Gyroscopic forces are always present. On a bike, the wheel is light enough
> and the speeds low enough that the weight-and-geometry forces always
> predominate. On a motorcycle, with much heavier mheels, that's not so. On my
> old RD-350, below 12-15 mph, if you wanted to turn left I cranked the bars
> left, and it steered sike a truck. Above that speed, to turn left I torqued
> the bars *right*. The resulting gyroscopic force leaned the cycle to the
> left, and then the weight-and-geometry caused the wheel to take up the
> slight angle to the left required for the turn.
Are you sure it is gyroscopic forces that lean the cycle over so that
you can turn?
David L. Johnson
>
> In article <3b906a1f$1...@news.estpak.ee>, "Erik" <er...@online.ee> wrote:
> >
> > the balance of the wheels or precision of the hub
> > bearings, or most likely combination of the both was not up
> > to the speed gained. resonance would be the keyword here...
>
> the shimmy stopped once he was off the bike.
>
But that second sentence does explain it.
> In article <010920010949338010%tim...@mac.com>, Tim McNamara
> <tim...@mac.com> wrote:
> ... I think you missed the point of the post,
> perhaps my fault. As speed increases, so too does the gyro effect. If the
> bike is designed with good steerign geometry, so that the forces generated
> in the application of the gyro effect are not destructive to keeping the
> front wheel up/in line, eventually, e.g. at 200mph on a heavy motorcycle
> wheel, it must contribute significantly to the stability,
The "gyroscopic effect", also known as angular momentum, will increase
linearly with speed. But what you saw was not that. What you saw was that
when the machine hit a certain, critical velocity, the shimmy appeared. That
is a resonance effect of the mechanical system; when the periodic motions of
the (not perfectly balanced) wheels, engine, etc., hit a certain frequency, it
began a "feedback" throughout the system. This has nothing to do with angular
momentum.
--
David L. Johnson
__o | Let's not escape into mathematics. Let's stay with reality. --
_`\(,_ | Michael Crichton
(_)/ (_) |
David L. Johnson
The short answer to your question is: yes. And, in fact, you can see this
effect. Watch someone water-skiing. The same sort of balance issues arise,
and even novices quickly learn to balance once the boat gets them to a
reasonable speed. Not too surpirisingly, that speed is similar to
bicycle-riding speed. There is no "gyroscopic effect" there.
The same would apply to snow skiing, but this is confused because you can
stand up when still on snow, not on water. Not most of us, anyway.
--
David L. Johnson
__o | "It doesn't get any easier, you just go faster." --Greg LeMond
_`\(,_ |
(_)/ (_) |
David L. Johnson
>
> In article <2Mjk7.4314$kN3....@typhoon.sonic.net>,
> jobst....@stanfordalumni.org wrote:
>
> > I'm talking about the folks who write here on wreck.bike. We have had
> > surveys and i often ask riders whose bicycles have wheels askew
> > whether the bicycle rides straight no-hands. The answer is invariably
> > in disbelief that I would even suggest such a dangerous act, followed
> > by "I never ride no-hands."
>
>
Not really. Often when riding with someone new, I will offer my hand to
shake. Twice now I have received a very strange reply, the rider saying that
no, he never takes even one hand off of the bar. And these are riders who
have done some miles; they were on 50+ mile rides. They were both 60+
year-old men, which might have had something to do with it, but I also know
other 60+ year-olds who are comfortable riding no hands.
At any rate, there are experiences riders who do not (cannot?) ride no hands,
or even one-handed. I have no idea what they would have done in the days of
down-tube shifters.
> All I can say is that its prevalent enough in these parts that I recall in
> days gone by periodic noise about passing bylaws to outlaw riding bikes
> with no hands. When we were children the police safety officers used to
> come to school and exhort us never to ride without hands, or even with only
> one hand, which of course went in one ear and out the other.
I do remember these admonitions. "Look ma, no hands! Look ma, no teeth!" is
an old joke.
--
David L. Johnson
__o | "What am I on? I'm on my bike, six hours a day, busting my ass.
_`\(,_ | What are you on?" --Lance Armstrong
(_)/ (_) |
Tim McNamara
<david....@lehigh.edu> wrote:
> "R. Himm" wrote:
> >
> > In article <3b906a1f$1...@news.estpak.ee>, "Erik" <er...@online.ee> wrote:
> > >
> > > the balance of the wheels or precision of the hub
> > > bearings, or most likely combination of the both was not up
> > > to the speed gained. resonance would be the keyword here...
> >
> > Apart from your second sentence, your first sentence does not explain why
> > the shimmy stopped once he was off the bike.
> >
> But that second sentence does explain it.
>
> > In article <010920010949338010%tim...@mac.com>, Tim McNamara
> > <tim...@mac.com> wrote:
No, I didn't.
> > ... I think you missed the point of the post,
> > perhaps my fault. As speed increases, so too does the gyro effect. If the
> > bike is designed with good steerign geometry, so that the forces generated
> > in the application of the gyro effect are not destructive to keeping the
> > front wheel up/in line, eventually, e.g. at 200mph on a heavy motorcycle
> > wheel, it must contribute significantly to the stability
Cheers!
Tim McNamara
<david....@lehigh.edu> wrote:
> "R. Himm" wrote:
> >
> > In article <2Mjk7.4314$kN3....@typhoon.sonic.net>,
> > jobst....@stanfordalumni.org wrote:
> >
> > > I'm talking about the folks who write here on wreck.bike. We have had
> > > surveys and i often ask riders whose bicycles have wheels askew
> > > whether the bicycle rides straight no-hands. The answer is invariably
> > > in disbelief that I would even suggest such a dangerous act, followed
> > > by "I never ride no-hands."
> >
> > Hmm. Wow. A strange place indeed.
> >
> Not really. Often when riding with someone new, I will offer my hand to
> shake. Twice now I have received a very strange reply, the rider saying that
> no, he never takes even one hand off of the bar. And these are riders who
> have done some miles; they were on 50+ mile rides. They were both 60+
> year-old men, which might have had something to do with it, but I also know
> other 60+ year-olds who are comfortable riding no hands.
>
> At any rate, there are experiences riders who do not (cannot?) ride no hands,
> or even one-handed. I have no idea what they would have done in the days of
> down-tube shifters.
I think that saddles may play into this. Bike racing saddles seem to
be getting narrower and narrower, and it is *really* unpleasant to ride
on them no handed. I also find that controlling the bike when riding
no-handed with a narrow saddle is more difficult- one of my sit bones
invariably slides off and suddenly the bike is canted to one side and
veering off towards the curb or into traffic. This never happens on my
bikes with wider saddles (B.17, Lepper, Avocet 040M, etc.) and those
bikes are nice to ride no-handed.
As long as we reinforce bike companies by buying the stupid stuff they
make, they'll keep making it!
jobst....@stanfordalumni.org
>> I'm talking about the folks who write here on wreck.bike. We have
>> had surveys and i often ask riders whose bicycles have wheels askew
>> whether the bicycle rides straight no-hands. The answer is
>> invariably in disbelief that I would even suggest such a dangerous
>> act, followed by "I never ride no-hands."
> Hmm. Wow. A strange place indeed.
>>> Some are weaving and a few are riding straight, but there they all
>>> are. Well, really I've never met anyone who doesn't ride no
>>> hands, and see it all the time on the streets amongst the hoi
>>> polloi. And while I agree the force is a little faint a low
>>> speeds I certainly find it strong when riding no hands at moderate
>>> speed downhill.
>> Maybe you could describe what sort of riders these are. We don't
>> have those around here.
> All I can say is that its prevalent enough in these parts that I
> recall in days gone by periodic noise about passing bylaws to outlaw
> riding bikes with no hands. When we were children the police safety
> officers used to come to school and exhort us never to ride without
> hands, or even with only one hand, which of course went in one ear
> and out the other. Now that they have helmet laws to make noise
> about this seems to have gone out of fashion.
Oh, "recall in days gone by"... sure everyone I knew rode no-hands but
these folks who buys the $.com titanium-carbon fiber etc bikes did not
ride in their formative years and find the whole concept as deadly
risky as riding down the driveway without a helmet. Just read the
tirades and rude suggestions offered here about the subject. In
Switzerland, I was once stopped on an empty and wide road for riding
no-hands. It is outlawed but seldom enforced there.
>> I'm not interested in parsing other peoples perception of bicycle
>> stability in minutia. The basic facts are as stated. If you can show
>> otherwise, pleas do.
> This fellow Jones wrote a paper of which you know quite well. He
> said that while he could indeed ride the bike, with the gyro
> canceled it handled differently or felt weird, it was difficult or
> impossible to ride without hands, and when riderless it fell over
> much quicker than without the gyro canceled. That's pretty
> straight forward English.
I'm not arguing about Jones' paper but rather what people quote from
it to prove that the bicycle is kept upright by gyroscopic forces. As
I said, his research should have had a different title, like "What
Importance do Gyroscopic Forces Have in Bicycling?" and go on to show
that when canceled, the bicycle cannot be ridden no-hands since that
is the means for steering in that mode. He put forth that he was
looking for the unridable bicycle, which as I pointed out is not a
realistic pursuit since it depends on the skill of the rider.
Jobst Brandt <jobst....@stanfordalumni.org>
jobst....@stanfordalumni.org
> As one of those who often says "i never ride no-hands" I think a bit
> of clarification is in order here.
> This does not mean I am unable to ride no hands, I have been able to
> do so for close to 50 years. Rather it is simply that I choose to
> ride with at least one hand on the bars at all times. In my
> experience most riders who have an interest in riding no-hands can
> do so, it is really not much of a skill IMHO.
> However in my personal experience, riding with no hands leaves one
> vulnerable to unseen road debris and road damage. This is one
> lesson I learned the hard way, I have the bad knee to remind me and
> I do not intend to repeat my previous mistake. There is little to
> gain and much to lose.
Well that gets back to the basic concept that just as you say no-hands
is frivolously dangerous, others refuse to ride on public roads for
the same reason. Where do you draw the line. I often take off or put
on a sweater wile riding, or eat and drink as we do often see riders
do in races. This is far less risky than descending with cars that go
so slowly that one must pass, not to be on the brakes all the way down
the hill. Most people don't do that either. It's all how sure you
are of these maneuvers. You may think these things are absolutes but
they are not. It boils down to the old concept:
# Everyone who descends faster than I is recklessly dangerous,
# everyone who is slower is a hopeless slug!"
You can hear this in its various forms regularly...
"You should have seen them descending like madmen..."
meaning the riders were faster than the speaker, nothing more. The
same goes for riding no-hands. All my top speeds are done tucked in,
elbows on knees, hands on the stem (aka no-hands) and I do it in
curves banked over steeply. "He descends like a madman..." as do all
my riding pals. It's old hat and we don't crash all the time, ending
in orthopedics.
Jobst Brandt <jobst....@stanfordalumni.org>
jobst....@stanfordalumni.org
> At any rate, there are experiences riders who do not (cannot?) ride
> no hands, or even one-handed. I have no idea what they would have
> done in the days of down-tube shifters.
That's the reason we don't have them anymore. Too many folks can't
shift them at all.
Jobst Brandt <jobst....@stanfordalumni.org>
jobst....@stanfordalumni.org
> I think that saddles may play into this. Bike racing saddles seem
> to be getting narrower and narrower, and it is *really* unpleasant
> to ride on them no handed. I also find that controlling the bike
> when riding no-handed with a narrow saddle is more difficult- one of
> my sit bones invariably slides off and suddenly the bike is canted
> to one side and veering off towards the curb or into traffic.
You must be getting old. I can ride no-hands while standing, saddle
between the legs and do slaloms or I can sit on the nose of the saddle
and do likewise. Your rear end must be getting soft. You didn't say
how saddle width enters into balancing the bicycle but I assume you
are uncomfortable.
Jobst Brandt <jobst....@stanfordalumni.org>
Tim McNamara
>Tim McNamara writes:
>
>> I think that saddles may play into this. Bike racing saddles seem
>> to be getting narrower and narrower, and it is *really* unpleasant
>> to ride on them no handed. I also find that controlling the bike
>> when riding no-handed with a narrow saddle is more difficult- one of
>> my sit bones invariably slides off and suddenly the bike is canted
>> to one side and veering off towards the curb or into traffic.
>
>You must be getting old. I can ride no-hands while standing, saddle
>between the legs and do slaloms or I can sit on the nose of the saddle
>and do likewise. Your rear end must be getting soft.
I can stand no handed, or at least I used to be able to, I haven't tried in years. No actual reason to do so. I don't think I've ever tried to do slaloms standing no handed- in fact I don't think it's ever occurred to me to try. I don't care to ride on the nose of any saddle I own.
>You didn't say how saddle width enters into balancing the bicycle but I assume you
>are uncomfortable.
Err, actually I did. In the last sentence of my paragraph. One of my sit bones slides off the saddle, which puts my weight well off to one side and makes the bike much harder to control no handed. Doesn't happen on my Brooks B.17, my Lepper Voyager or my Avocet 40M; for that matter it doesn't happen on the Ritchey WCS turbo clone on my race bike. But it has happened on really narrow saddles like the Rolls Due.
I keep the saddles that are comfortable, no reason to turn bicycling into a torture test. So, no, I am not uncomfortable on my bikes. I rarely ever think about saddles while I am riding, so they must be OK.
Jon Isaacs
>is frivolously dangerous, others refuse to ride on public roads for
>the same reason. Where do you draw the line. I often take off or put
>on a sweater wile riding, or eat and drink as we do often see riders
>do in races. This is far less risky than descending with cars that go
>so slowly that one must pass, not to be on the brakes all the way down
>the hill.
How you ride and how I ride are just different. My primary transportation was
a motorcycle until I was about 40 and the various thrills that I experienced
were enough to last a lifetime. There is nothing on a bicycle that can open
your eyes quite like being on a half mile dirt track on a 750cc TT bike and
discover at the end of the straight that it has started to rain and that the
track is slick.
>It boils down to the old concept:
>
># Everyone who descends faster than I is recklessly dangerous,
># everyone who is slower is a hopeless slug!"
For me what it boils down to is that I am comfortable riding they way I do and
I am comfortable with you riding the way you do. But the reason I ride like I
do is not that I cannot ride some other way but rather than I choose not to.
The most extreme case of riding no-hands I ever saw (except for my own case of
stupidity) was a fellow heading down Torrey Pines grade. The bike lane is 2-3
feet wide with a railing on one side and slot wider than the rear tire on the
other. This fellow spins up to about 40 mph and then takes both hands off the
bars leans forward and puts them behind his back.
Anyway, getting back to the original point. The assumption that riders do not
ride no-hands because they cannot do so is faulty. Riding no-hands is a skill
most of us learned as children.
jon isaacs
Pete Biggs
"Tim McNamara" <tim...@mac.com> wrote in message
news:020920012121472978%tim...@mac.com...
>
> I think that saddles may play into this. Bike racing saddles seem to
> be getting narrower and narrower, and it is *really* unpleasant to ride
> on them no handed. I also find that controlling the bike when riding
> no-handed with a narrow saddle is more difficult- one of my sit bones
> invariably slides off and suddenly the bike is canted to one side and
> veering off towards the curb or into traffic. This never happens on my
> bikes with wider saddles (B.17, Lepper, Avocet 040M, etc.) and those
> bikes are nice to ride no-handed.
I find the same thing, but the geometry of the bike (and suitability to the
rider) makes more difference. I find riding no-hands on one bike quite
difficult altogether, but easy on another--I can even ride round corners on
it no-handed. A couple of beers help though!
- Pete Biggs
Jeff Wills
> I'm not arguing about Jones' paper but rather what people quote from
> it to prove that the bicycle is kept upright by gyroscopic forces. As
> I said, his research should have had a different title, like "What
> Importance do Gyroscopic Forces Have in Bicycling?" and go on to show
> that when canceled, the bicycle cannot be ridden no-hands since that
> is the means for steering in that mode. He put forth that he was
> looking for the unridable bicycle, which as I pointed out is not a
> realistic pursuit since it depends on the skill of the rider.
>
> Jobst Brandt <jobst....@stanfordalumni.org>
As further evidence of bikes not need gyroscopic forces to stay
upright, take a look at
http://www2.bitstream.net/~dkrafft/icebike/icepics/brick00.jpg . This
is clearly a bicycle that does not have any gyroscopic forces occuring
in front- yet it appears to be rideable.
For similar evidence of the effect of Minnesota's long winters, take a
look at
http://www2.bitstream.net/~dkrafft/icebike/icerace.html .
Jeff
Nick Maclaren
In article <20010902092038...@mb-ba.aol.com>,
joni...@aol.com (Jon Isaacs) writes:
|>
|> As one of those who often says "i never ride no-hands" I think a bit of
|> clarification is in order here.
|>
|> This does not mean I am unable to ride no hands, I have been able to do so for
|> close to 50 years.
|>
|> Rather it is simply that I choose to ride with at least one hand on the bars at
|> all times.
|>
|> In my experience most riders who have an interest in riding no-hands can do so,
|> it is really not much of a skill IMHO.
You are wrong, I am afraid. It requires good middle-ear balance.
Of the three normal methods of balancing, sight is too slow, touch
needs at least one hand on the handlebars, and that leaves the
circular canals. And 20% of the population have loss of function
in the middle ear, even ignoring those with heavy colds!
I have serious middle-ear damage, and balance almost by sight and
touch alone - I cannot ride no hands, and even riding with one
hand requires a stable bicycle.
|> However in my personal experience, riding with no hands leaves one vulnerable
|> to unseen road debris and road damage. This is one lesson I learned the hard
|> way, I have the bad knee to remind me and I do not intend to repeat my previous
|> mistake. There is little to gain and much to lose.
This is true even riding one-handed. Few people can control a
bicycle if they hit anything serious with only one hand on the
bars, but I agree that riding no hands is far more likely to
cause a loss of control.
Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QG, England.
Email: nm...@cam.ac.uk
Tel.: +44 1223 334761 Fax: +44 1223 334679
Bikerider
a stable design of course), even without a rider, is attributed to
simple inertia, yet gyroscopic inertia of the wheels is considered
almost insignificant.
I guess the ONLY way to prove or disprove this is to get a bicycle
onto a treadmill arrangement, so that the bike doesn't move relative
to anything except the belt on the treadmill, and see how much
gyroscopic inertial stability matters, or doesn't.
Mark McMaster
>
> In article <20010902092038...@mb-ba.aol.com>,
> joni...@aol.com (Jon Isaacs) writes:
> |> However in my personal experience, riding with no hands leaves one vulnerable
> |> to unseen road debris and road damage. This is one lesson I learned the hard
> |> way, I have the bad knee to remind me and I do not intend to repeat my previous
> |> mistake. There is little to gain and much to lose.
>
> This is true even riding one-handed. Few people can control a
> bicycle if they hit anything serious with only one hand on the
> bars, but I agree that riding no hands is far more likely to
> cause a loss of control.
I disagree. It is often the riders reaction (or
over-reaction) that causes them to lose control when hitting
an obstacle while riding with one or no hands, not the
obstacle itself, at least when riding in a relatively
straight line. Since the wheels are directly aligned with
the rider's CG, hitting an obstacle usually just results in
a directly upward, or upward and backward force, inline with
the rider's CG.
I've gone over bumps and road debris while riding no handed
with no loss of control. While riding one handed downhill
once I was distracted (waving to a friend going up the hill)
and hit a pothole hard enough to pinch flat my front tire -
also with no loss of control. Often when riding with a
group and approaching a stop sign at the bottom of a steep
hill I'll signal the stop with my right hand, while braking
hard with my left hand. While riding downhill I often
assume a tight tuck with my hands next to the stem. If I
approach a rough patch of road, I simply lift my butt from
the saddle so my legs can absorb the shock, while keeping my
hands next the stem, knowing that any jarring from the rough
road will result in purely vertical forces, and therefore
the additional steering control from having my hands further
out on the bar is not needed.
Mark McMaster
MMc...@ix.netcom.com
Carl
"Tim McNamara" <tim...@mac.com> wrote in message
news:020920012121472978%tim...@mac.com...
Amen, I cannot find any of the seats that I used back in the late 80's early
90's before I quit riding the first time around. (Brooks something or
another, not the old leather style).
jobst....@stanfordalumni.org
> You are wrong, I am afraid. It requires good middle-ear balance.
> Of the three normal methods of balancing, sight is too slow, touch
> needs at least one hand on the handlebars, and that leaves the
> circular canals. And 20% of the population have loss of function in
> the middle ear, even ignoring those with heavy colds!
Not so. Where do you get that. I suggest you read the FAQ item on
descending and note that I had a middle ear disturbance once that
rotated my sense of down by 90 degrees or so, so that I fell over when
closing my eyes. In that state, I could descend winding roads as fast
as ever from visual means. How do you propose the middle ear (like a
plumb bob in moving vehicle) has any idea where "down" is.
> I have serious middle-ear damage, and balance almost by sight and
> touch alone - I cannot ride no hands, and even riding with one
> hand requires a stable bicycle.
You have other problems. Don't extend that to an explanation of how
people stay upright.
>>> However in my personal experience, riding with no hands leaves one
>>> vulnerable to unseen road debris and road damage. This is one
>>> lesson I learned the hard way, I have the bad knee to remind me
>>> and I do not intend to repeat my previous mistake. There is
>>> little to gain and much to lose.
> This is true even riding one-handed. Few people can control a
> bicycle if they hit anything serious with only one hand on the
> bars, but I agree that riding no hands is far more likely to
> cause a loss of control.
Not true. One handed causes steering motions while no handed does
not. I have often let go of the other hand while riding one handed on
encountering a bump in the road to avoid this effect. I get the
impression that much of this discussion is based on untried
theoretical perceptions. It takes more than that to analyze such
matters. I suggest a keen sense of observation and an understanding
of what physical effects apply.
That one chooses to not ride no-hands indicates that the rider feels
there is not enough safety margin to do it safely. The same goes for
old folks who are afraid to cross the street because they cannot jump
out of the way in an emergency. I know how that feels from when I had
a sprained ankle and couldn't run. Crosswalks became danger zones for
me that I had not known before... or after.
When I hurry down a mountain and pass a car that speeds up
inadvertently when I am even with the driver, I don't hesitate to
knock on his window as we enter a curve at speed. This works miracles
and is not as hazardous as it may appear if you are agile on the
bicycle. It's all relative to the speed at which one processes events
and is able to respond to them. I also have neighbors who have AARP
lights along the front walk and garden, even in bushes and trees.
They are terrified of the dark and wouldn't go there at night... or
for that matter ride a bicycle no-hands.
Jobst Brandt <jobst....@stanfordalumni.org>
jobst....@stanfordalumni.org
>> As further evidence of bikes not need gyroscopic forces to stay
> I don't think anyone has ever disputed that, certainly not in this thread.
That is incorrect. This thread is a vehicle to promote the concept of
bicycle stability through gyroscopic forces. You may not think so but
those of us who have been here a while know the earmarks of the ilk.
> We already know gyroscopic forces are unnecessary for two reasons:
> because if it were the case, either everyone would be able to ride a
> bike without learning- just get it going fast enough- or else no one
> would be able to ride a bike, there being no available means to get
> it going fast enough without falling over first.
That is no proof at all and that you mention it makes me think you
don't understand the concept. As was carefully developed, no-hands
riding is not simple for many because they cannot make use of the
gyroscopic forces, therefore, these same people could not ride a
bicycle even if these forces were the ones that keep the bicycle
upright because they would perturb them as they do when trying to ride
no-hands.
Your arguments make little sense.
Jobst Brandt <jobst....@stanfordalumni.org>
Kevin
simpler. My 11 yr old does it at very slow speeds and with much control. I
always feel "scared" and cna only do it at higher speeds while pedaling and
then only for short times.
Kevin
<jobst....@stanfordalumni.org> wrote in message
news:f6Vk7.186$N64....@typhoon.sonic.net...
Tho X. Bui
I don't think riding on rollers will prove your point, Bikerider. The
correcting effect of trail is relative to the contact patch, not to the
"absolute" frame of reference. I have found that riding no handed on
rollers is very, very difficult. I attribute this to the nature of the
small radius of the front drum. Once the bike leans over too much, the
effect is accelerated deflection of the front wheel to one side--too
much defection to correct with no hands on the bar.
Tho
Tim McNamara
<jobst....@stanfordalumni.org> wrote:
> Not so. Where do you get that. I suggest you read the FAQ item on
> descending and note that I had a middle ear disturbance once that
> rotated my sense of down by 90 degrees or so, so that I fell over when
> closing my eyes. In that state, I could descend winding roads as fast
> as ever from visual means. How do you propose the middle ear (like a
> plumb bob in moving vehicle) has any idea where "down" is.
A good point. Spatial orientation is a complex multi-modal function.
It involves the inner ear (cochlea), vision and proprioception
(feedback from the muscles about positioning), as well as sensations
from contact with the environment (feet on floor, etc).
You can rotate your head forward and and still know which way is down,
which you could not do if balance was merely dependent on cochlear
data. Developing an inner ear disorder such as Meniere's disease would
render one incapable of balance and of things like walking, yet people
so afflicted manage to get around albeit with dizziness- because they
can orient themselves visually and proprioceptively.
Divers and astronauts can lose spatial orientation because they lose of
the loss of one or more of the sense modalities involved in balance.
In the case of astronauts, they lose both the effects of gravity in the
cochlea and also in terms of proprioception- the "antigravity muscles"
are not under tension and thus offer no feedback to the brain. The
latter effect afflicts divers, who also can lose visual cues for
orientation but retain the effects of gravity on the inner ear. People
in a whiteout, who retain both inner ear and proprioception, also are
known to become disoriented and have balance problems because there is
no horizon or verticals to use to orient. There are a number of places
in the US that offer the amusement of specially constructed visual
tricks to disorient one (quite instructive, actually, to the student of
perceptual psychology).
The cochlea is certainly very important and the effects of disease or
malfunction can be quite dramatic, as noted by Jobst and also by people
with Meniere's or, for that matter, motion sickness. But it is not the
*only* means by which balance and spatial orientation are achieved.
Tim McNamara
> I get the impression that much of this discussion is based on untried
> theoretical perceptions. It takes more than that to analyze such
> matters. I suggest a keen sense of observation and an understanding
> of what physical effects apply.
Surely you aren't suggesting that we actually go out and ride bikes?
David L. Johnson
> I don't think riding on rollers will prove your point, Bikerider. The
> correcting effect of trail is relative to the contact patch, not to the
> "absolute" frame of reference. I have found that riding no handed on
> rollers is very, very difficult.
Heck, most of us find riding on rollers with two hands to be difficult (as
well as no fun). But I have seen someone ride on rollers no-handed. It can
be done. Not by me, though.
--
David L. Johnson
__o | And though I have the gift of prophecy, and understand all
_`\(,_ | mysteries, and all knowledge; and though I have all faith, so
(_)/ (_) | that I could remove mountains, and have not charity, I am
nothing. [1 Corinth. 13:2]
Nick Maclaren
In article <030920012204122899%tim...@mac.com>, Tim McNamara <tim...@mac.com> writes:
|> In article <p_Uk7.184$N64....@typhoon.sonic.net>,
|> <jobst....@stanfordalumni.org> wrote:
|>
|> > Not so. Where do you get that. I suggest you read the FAQ item on
|> > descending and note that I had a middle ear disturbance once that
|> > rotated my sense of down by 90 degrees or so, so that I fell over when
|> > closing my eyes. In that state, I could descend winding roads as fast
|> > as ever from visual means. How do you propose the middle ear (like a
|> > plumb bob in moving vehicle) has any idea where "down" is.
|>
|> A good point. Spatial orientation is a complex multi-modal function.
|> It involves the inner ear (cochlea), vision and proprioception
|> (feedback from the muscles about positioning), as well as sensations
|> from contact with the environment (feet on floor, etc).
That was my much of my point. I have never heard of a symptom
like the one that Jobst Brandt describes but, in any case, it is
irrelevant.
The title of this thread is shimmy, and is relevant. It is an
phenomenon with a timescale of fractions of a second - at a rough
guess, about a tenth of a second. And it is one of VERY small
changes in the angle of the front wheel and handlebars, often
triggered by road surfaces, but then involving the rider. It is
closely related to how a cyclist maintains his balance in response
to movements of the front wheel and handlebars forced by road
irregularities, rather than waiting until the imbalance becomes
gross.
As is well-known to people who study it, the visual system has
actually quite long time lags in it, and the brain compensates.
But that means it can't be used to correct for short timescale,
unpredictable changes, such as are involved in shimmy and keeping
balance against road irregularities. It is therefore irrelevant
in this context, though it IS one of the main ways that you tell
up from down.
Similarly, the sensation of up and down is FAR too coarse for this
purpose, and I doubt that it is used at all, so I am not surprised
that Jobst Brandt's weird problem had little effect.
This leaves the semi-circular canals and touch, which in this
context is mainly through the hands. Now, riding two handed
means that you can use the differential information to correct
movements, which is fast and reliable. Riding one handed is
much harder, and leads to over-correction, as other people have
pointed out. And, of course, riding no handed means that you
have no feedback through your hands, and therefore the only way
that you can tell what the front wheel is doing is by the gross
movements of the bicycle!
While some people may be able to balance a bicycle using touch
though the saddle and pedals alone, I doubt that most can, and
am pretty certain that most people will need functioning semi-
circular canals. Hence my remark.
But, to repeat, this is SEPARATE from the matter of gross
positioning, which is probably done mostly by sight even in
people with good normal balance. This is all about the very
short timescale corrections due to road irregularities.
Nick Maclaren
In article <3B93FA00...@ix.netcom.com>,
Mark McMaster <MMc...@ix.netcom.com> writes:
|> >
|> > This is true even riding one-handed. Few people can control a
|> > bicycle if they hit anything serious with only one hand on the
|> > bars, but I agree that riding no hands is far more likely to
|> > cause a loss of control.
|>
|> I disagree. It is often the riders reaction (or
|> over-reaction) that causes them to lose control when hitting
|> an obstacle while riding with one or no hands, not the
|> obstacle itself, at least when riding in a relatively
|> straight line. Since the wheels are directly aligned with
|> the rider's CG, hitting an obstacle usually just results in
|> a directly upward, or upward and backward force, inline with
|> the rider's CG.
While that is true, it assume that all irregularities are normal
to the rider's direction! In general, they are, but occasionally
they aren't. Now let us consider what happens if a front wheel
hits a piece of ironwork aligned diagonally, hits the edge of a
pothole, or does something similar.
The wheel will be turned by it, clearly. Now, typical bicycle
front wheels are self-correcting for very small movements, but
are seriously unstable for larger ones. The other problem is
that a no hands rider has to sit back and, with drop handlebars,
will need a good fraction of a second to reach the bars again.
If he fails to get there before the wheel reaches the critical
angle, it will flip round and he will go over the bars.
Now, hitting a significant diagonally aligned irregularity may
be rare, but it is likely to cause a serious crash. Riding one
handed is MORE likely to have trouble, but arguably less likely
to hit SERIOUS trouble. And, when I made my remark, I was
thinking of enough loss of control to cause a crash.
If, however, you disagree, you may be right. I stand by my
remark, but it is a matter of judgement of a complex situation.
"The truth is rarely pure and never simple".
Mark Hickey
>Bikerider wrote:
>>
>> I guess the ONLY way to prove or disprove this is to get a bicycle
>> onto a treadmill arrangement, so that the bike doesn't move relative
>> to anything except the belt on the treadmill, and see how much
>> gyroscopic inertial stability matters, or doesn't.
>
>I don't think riding on rollers will prove your point, Bikerider. The
>correcting effect of trail is relative to the contact patch, not to the
>"absolute" frame of reference. I have found that riding no handed on
>rollers is very, very difficult. I attribute this to the nature of the
>small radius of the front drum. Once the bike leans over too much, the
>effect is accelerated deflection of the front wheel to one side--too
>much defection to correct with no hands on the bar.
The adjustment of the rollers will alter the contact patch point on
the front tire. This effectively changes the trail of the fork (since
trail is the relationship of the line through the center of the head
tube and the contact patch of the tire).
So, the rollers can be adjusted to supply similar trail (though I
would guess most opt for a little less). I've had no problem riding
rollers hands-off, and in fact got to the point one long, cold winter
(no, not in Florida or Arizona) where I could take my jersey off while
riding rollers.
Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame
Bikerider
posted:
>I don't think riding on rollers will prove your point, Bikerider.
Not on rollers, on a belt similar to those found on treadmills, which
provide a flat surface for running.
>The
>correcting effect of trail is relative to the contact patch, not to the
>"absolute" frame of reference.
I saw that in the article too, but I'd sure like to see it all
quantified as well as qualified by measuring it in Practice rather
than theory. The suspension fork on my bike is quite a departure from
that of my road machine, the front wheel axis is so closely in line
with the steering axis as to make the bike very 'twitchy' (poor low
speed castering), but also extremely maneuverable. Yet, once I get up
to speed, around 10mph or greater, I can ride it no-hands, indicating
that gyroscopic stability, at least every bit as much as 'trail' plays
a part here.
>I have found that riding no handed on
>rollers is very, very difficult. I attribute this to the nature of the
>small radius of the front drum.
That's why I suggest a belt arrangement, to eliminate such distortion
of riding on rollers.
>Once the bike leans over too much, the
>effect is accelerated deflection of the front wheel to one side--too
>much defection to correct with no hands on the bar.
Either that or it will oscillate, often violently.
R. Himm
jobst....@stanfordalumni.org wrote:
> This thread is a vehicle to promote the concept of
> bicycle stability through gyroscopic forces. You may not think so but
> those of us who have been here a while know the earmarks of the ilk.
> don't understand the concept. As was carefully developed, no-hands
> riding is not simple for many because they cannot make use of the
> gyroscopic forces, therefore, these same people could not ride a
> bicycle even if these forces were the ones that keep the bicycle
> upright because they would perturb them as they do when trying to ride
> no-hands.
>
> Your arguments make little sense.
These paragraphs are interesting to read in conjunction. Moving on:
Asserting something on the basis of casual surveys is not carefully
developing, especially when people whose opinions you base your arguments
on write back to tell you that you have misinterpreted them. You propose an
at first blush plausible but ultimately superficial counter-argument, that
if they don't feel no hands is safe, it must be because they do not have
the skill level to make it so. But you fail to take into account that their
stance may be top-down instead of bottom-up, so to speak, i.e. that they
feel this way because of preconceptions, not perceptions and sensations and
the ability to act on them, or lack thereof. You certainly do not need the
bicyclist's counterpart to a perfumer's nose or a wine taster's palette to
ride no hands.
If you were the only one who could do it, I would readily accept that it
requires some kind of incredibly oversensitive ass to ride no hands. But
that otherwise reasonable hypothesis of necessity, if not sufficiency, is
negated by the fact that nearly everyone and his mother can do it.
Tim McNamara
<nm...@cus.cam.ac.uk> wrote:
> As is well-known to people who study it, the visual system has
> actually quite long time lags in it, and the brain compensates.
> But that means it can't be used to correct for short timescale,
> unpredictable changes, such as are involved in shimmy and keeping
> balance against road irregularities. It is therefore irrelevant
> in this context, though it IS one of the main ways that you tell
> up from down.
IIRC from my perception course back in my grad school days, the nervous
system operates at about a 1/60th of a second time lag for
registration. Do you consider that long?
Making a behavioral-motor choice can take somewhat longer, but of
course familiarity with the situation (learning) reduces that process
considerably. That's why children learning to ride bike have a wobbly
overcorrected course, snaking back and forth across the sidewalk (plus
most children's bikes having atrociously bad steering geometry). Once
they've learned the task, they ride by making small almost
imperceptible corrections and ride in a nearly straight line.
> Similarly, the sensation of up and down is FAR too coarse for this
> purpose, and I doubt that it is used at all, so I am not surprised
> that Jobst Brandt's weird problem had little effect.
His problem had little effect because it is only one of the modalities
used for balance and spatial orientation. He- like many other people
with an impairment or loss of a modality- was able to compensate and
operate nearly normally in most situations. Although I wouldn't be
surprised if he had some nausea whle descending curvy roads.
> This leaves the semi-circular canals and touch, which in this
> context is mainly through the hands.
You ride with your eyes closed? Much of your "sense of balance" is
dependent on visual cues such as horizon and verticals, as well as
depth perception. Wear a patch over one eye and ride down a familiar
descent and see what I mean. Or try riding blindfolded somewhere safe
and try to stay upright.
> Now, riding two handed means that you can use the differential
> information to correct movements, which is fast and reliable.
What "differential information" is that?
> Riding one handed is much harder, and leads to over-correction, as
> other people have pointed out.
No, it doesn't. Well, people riding one handed may be more prone to
overcorrection because of the emotional reaction, but that's not why
people crash if they hit a road obstacle riding one handed. They crash
because the obstacle slows or deflects the bicycle, and the momentum of
their body on one side of the bars causes the bar to turn. They've
crashed before they've had a chance to overcorrect.
This is compounded by an overly low bar position, BTW. I remember
having NO problem riding for miles one handed on my old English 3 speed
when I was a kid with upright bars- there was nearly no weight on the
bars because I wasn't bent over into an aero position.
> And, of course, riding no handed means that you
> have no feedback through your hands, and therefore the only way
> that you can tell what the front wheel is doing is by the gross
> movements of the bicycle!
Or by watching the stem movements, or by the lean angle of the bike as
felt through the saddle and pedals.
You are remarkably overrestrictive in your conceptualization about
human perception. Humans are designed to function with a Gestalt
synthesis of sensory modalities, structuring a perceptual whole from
the varied data of the field. It's hardwired into the nervous system.
This is an automatic process, although it can be fooled by deliberately
constructed artificial situations and also by completely novel
situations.
For your further edification, I recommend _Perception: The World
Transformed_ by Kaufman, as well as anything you can find by
Wertheimer, Koffka, and/or Köhler.
terry morse
> Divers and astronauts can lose spatial orientation because they lose of
> the loss of one or more of the sense modalities involved in balance.
> In the case of astronauts, they lose both the effects of gravity in the
> cochlea and also in terms of proprioception- the "antigravity muscles"
> are not under tension and thus offer no feedback to the brain. The
> latter effect afflicts divers, who also can lose visual cues for
> orientation but retain the effects of gravity on the inner ear. People
> in a whiteout, who retain both inner ear and proprioception, also are
> known to become disoriented and have balance problems because there is
> no horizon or verticals to use to orient.
There's an interesting every day illusion that shows how powerful
vision is to our notion of "where is up". If you look straight forward
on a commercial jet while it is accelerating down the runway, it looks
as if the aisle has tilted upwards. This is logical, since the
acceleration changes our local sense of up and down. But now, if you
look out the window at the horizon, the illusion of the tilted aisle
goes away immediately, and our mind forces the aisle back to
horizontal.
--
terry morse
Palo Alto, CA
http://www.terrymorse.com/bike/
Jon Isaacs
>the rider's CG, hitting an obstacle usually just results in
>a directly upward, or upward and backward force, inline with
>the rider's CG.
Nice to hit those obstacles that happen to square with your direction or
travel.
Today I was riding along and a fellow came up behind and started drafting me a
foot or so back. THen I happened to notice that he was riding no-hands.
I slowed and waved him around, suggesting that it was fine to ride behind me
but if he wanted to do so, please ride with his both hands on the bars.
jon isaacs
Jon Isaacs
>to the rider's direction! In general, they are, but occasionally
>they aren't. Now let us consider what happens if a front wheel
>hits a piece of ironwork aligned diagonally, hits the edge of a
>pothole, or does something similar.
I might just add that both hands on the bars allows those quick last second
manuveurs like bunny hops that can help avoid obstacles.
While it is clear that it is possible to ride no-hands it is also clear that
there is an added risk associated with it.
jon isaacs
Phil Brown
motorcycles. The current record, which he holds, was about 195 mph, while
his goal was to break 200. >>
The current record is over 300mph set by Don Vesco.
Phil Brown
jobst....@stanfordalumni.org
> If you were the only one who could do it, I would readily accept
> that it requires some kind of incredibly oversensitive ass to ride
> no hands. But that otherwise reasonable hypothesis of necessity, if
> not sufficiency, is negated by the fact that nearly everyone and his
> mother can do it.
They claim they can but don't. That's a lot like people who walk with
canes or a walker saying they can do without. It depends on the
facility with which they "can" do it. Face it, those who believe
riding no-hands to be dangerous are not good at it, in fact they are
poor at it. How poor is unclear but I don't know why you persist in
making it seem like some manner of prudent caution not to ride
no-hands. In that vein there are people who find bicycling in general
too dangerous. They prefer a bike path with a lawn on either side in
the event of a fall.
Jobst Brandt <jobst....@stanfordalumni.org>
Benjamin Weiner
> ... The suspension fork on my bike is quite a departure from
> that of my road machine, the front wheel axis is so closely in line
> with the steering axis as to make the bike very 'twitchy' (poor low
> speed castering), but also extremely maneuverable.
What you describe is a fork with very little rake.
This produces a front end with more trail, not less.
More trail is generally said to make a bike handle
slower and less twitchily. Extreme examples are
old bikes for motorpacing which had reversed forks
(negative rake and extremely large trail).
> Yet, once I get up
> to speed, around 10mph or greater, I can ride it no-hands, indicating
> that gyroscopic stability, at least every bit as much as 'trail' plays
> a part here.
Are you saying that gyroscopic stability is important
at speeds >10 mph for all riding, not just no-hands?
I don't believe that your example proves this.
At least, it hasn't been demonstrated.
Mark McMaster
I was out for a bike ride shortly after I wrote the above,
so just for giggles and yucks I purposely rode no handed
over various road irregularities. In the course of the ride
I rode over various size and shaped pot holes and other
pavement discontinuities, raised utility covers, sunken
sewer grates, railroad tracks, etc., all at typical casual
riding speeds (15-20 mph). Not being able to rise out of
the saddle I got quite bounced and jostled around quite a
lot, but primarily in the vertical direction. However, I
did not fall or lose control of the bike.
The various road irregularities were struck at varying
angles from the wheels (being that they were irregular,
after all), including a double set of railroad tracks which
were at an angle of about 30 degrees from the perpendicular
of the road, but the none of them caused the wheels to be
turned. The tire's contact patch is very narrow, so even an
obstacle at an extreme angle exerts only a small (and short
duration) turning moment on the wheel. As long as the wheel
can roll over the obstacle, there will be little angular
deflection.
Admittedly, it is easier to lose one's perch on a bicycle
when hitting large objects when riding no handed, and
therefore there is more chance of losing control, but it is
hardly a foregone conclusion that hitting an obstacle while
riding no handed _will_ cause lose of control.
Mark McMaster
MMc...@ix.netcom.com
jobst....@stanfordalumni.org
>> If, however, you disagree, you may be right. I stand by my remark,
>> but it is a matter of judgment of a complex situation.
> I was out for a bike ride shortly after I wrote the above, so just
> for giggles and yucks I purposely rode no handed over various road
> irregularities. In the course of the ride I rode over various size
> and shaped pot holes and other pavement discontinuities, raised
> utility covers, sunken sewer grates, railroad tracks, etc., all at
> typical casual riding speeds (15-20 mph).
> Not being able to rise out of the saddle I got quite bounced and
> jostled around quite a lot, but primarily in the vertical direction.
> However, I did not fall or lose control of the bike.
I'm glad you took up the effort. I don't like being the lone ranger
here any more than others because the attack frenzy becomes
overwhelming. Just the same, let me suggest you try the experiment
again and try standing up. It's not hard. Just lean back to your
balance position and stand up while clamping the saddle between the
legs. That's how you stand but just unloading the saddle with a bit
of clearance is enough to suspend harsh bumps.
> The various road irregularities were struck at varying angles from
> the wheels (being that they were irregular, after all), including a
> double set of railroad tracks which were at an angle of about 30
> degrees from the perpendicular of the road, but the none of them
> caused the wheels to be turned. The tire's contact patch is narrow,
> so even an obstacle at an extreme angle exerts only a small (and
> short duration) turning moment on the wheel. As long as the wheel
> can roll over the obstacle, there will be little angular deflection.
The reason you we needed to do these exercises is that you are
confronting an audience that has not tried riding no-hands except for
moments and who have a gory imagination of what will happen because it
is an extreme hazard. Those of us who do it regularly do so on
trails, fast descents and in curves and don't give it a thought. It's
part of bicycling.
Riding one handed, on the other hand, is hazardous over obstacles. In
such incidents, if the obstacle is one that can be ridden over rather
than jumped, I let go with the other hand because unilateral steering
throws the bicycle off course as it encounters the bump. You can test
this on washboard road where no-hands is easy but one handed is a
mess.
> Admittedly, it is easier to lose one's perch on a bicycle when
> hitting large objects when riding no handed, and therefore there is
> more chance of losing control, but it is hardly a foregone
> conclusion that hitting an obstacle while riding no handed _will_
> cause lose of control.
Well stated, but then we've said that often before in these discussions.
Jobst Brandt <jobst....@stanfordalumni.org>
Nick Maclaren
In article <37il7.394$bJ2....@typhoon.sonic.net>,
jobst....@stanfordalumni.org writes:
|>
|> The reason you we needed to do these exercises is that you are
|> confronting an audience that has not tried riding no-hands except for
|> moments and who have a gory imagination of what will happen because it
|> is an extreme hazard. Those of us who do it regularly do so on
|> trails, fast descents and in curves and don't give it a thought. It's
|> part of bicycling.
You are quite simply wrong.
I have tried more than once, and could not maintain stability.
In particular, the sensations though my legs are not enough to
tell that the front wheel is starting to turn sideways.
I have also observed what happens when people who can clearly do
it (because they ARE doing it!) hit a road irregularity that
they are not expecting. While most do not come off, some do.
And a large number than actually come off lose control enough
for it to be clear that they have very nearly come off.
I am pretty certain that my description of the problem is right
in principle, but it is a complex enough problem that the details
are less than obvious and make a lot of difference.
|> > Admittedly, it is easier to lose one's perch on a bicycle when
|> > hitting large objects when riding no handed, and therefore there is
|> > more chance of losing control, but it is hardly a foregone
|> > conclusion that hitting an obstacle while riding no handed _will_
|> > cause lose of control.
|>
|> Well stated, but then we've said that often before in these discussions.
That is obviously true, but it is equally false to say that ONLY
coming off one's perch will cause a loss of control. Mark McMaster's
experiment is interesting, but doesn't actually affect my point, as
you can tell if you think harder about it.
In order for an obstacle to turn the wheel significantly, it must
be at an angle (clearly), but it must also be sudden and deep enough
to have enough leverage to do so - and there may be more factors.
In the past, I have certainly noticed the effect that riding over
the edge of pothole does not always cause a significant turning
moment, even when I thought that it should have done; I don't know
why.
But, occasionally, I go over an obstacle that turns the wheel hard
enough to give me trouble holding it in a line even with BOTH hands
on the handlebars. Now, it is THAT sort of a problem that WILL flip
the front wheel if riding with no hands - what I can't say is what
the precise cause is or how frequent it is. A single test does not
disprove the existence of such problems.
Nick Maclaren
In article <040920010909560277%tim...@mac.com>,
Tim McNamara <tim...@mac.com> writes:
|>
|> IIRC from my perception course back in my grad school days, the nervous
|> system operates at about a 1/60th of a second time lag for
|> registration. Do you consider that long?
Registration is not the whole task - analysis is! The note (bill)
test is indicative - you know the one where you hold your fingers
an inch or so either side of a note held vertically by someone
else and you try and catch it as it drops. You have a WHOLE 0.2
seconds in which to catch it, and most people can't - I can, still.
As I understand it, non-trivial vision tasks (i.e. ones that don't
have hard-wired circuitry in the brain) take more like 0.1 seconds;
the smaller figure is only for ones that have specific neural circuits.
But, yes, even for the latter, you will REGISTER the sight - what you
will not have done is converted it into a concept.
|> Making a behavioral-motor choice can take somewhat longer, but of
|> course familiarity with the situation (learning) reduces that process
|> considerably. That's why children learning to ride bike have a wobbly
|> overcorrected course, snaking back and forth across the sidewalk (plus
|> most children's bikes having atrociously bad steering geometry). Once
|> they've learned the task, they ride by making small almost
|> imperceptible corrections and ride in a nearly straight line.
No, that is wrong. There are two phenomena involved. One is that
of keeping the steering steady (i.e. the anti-shimmy effect),
which gives the rider longer in which to make the decisions about
balance proper. And this is primarily a matter of training the
reflexes using the sensation of touch in the hands.
Once that is learnt, things are a LOT easier, because the timescale
changed from something like a tenth of second to nearer a second,
and I quite agree that sight comes into that second stage.
|> > This leaves the semi-circular canals and touch, which in this
|> > context is mainly through the hands.
|>
|> You ride with your eyes closed? Much of your "sense of balance" is
|> dependent on visual cues such as horizon and verticals, as well as
|> depth perception. Wear a patch over one eye and ride down a familiar
|> descent and see what I mean. Or try riding blindfolded somewhere safe
|> and try to stay upright.
Oh, for heaven's sake! That was one of the FIRST things that I
said! With my malfunctioning ears, vision is my MAIN sense of
balance ....
|> > Now, riding two handed means that you can use the differential
|> > information to correct movements, which is fast and reliable.
|>
|> What "differential information" is that?
The difference in pressure between your hands, as well as the
the difference in the amount you push.
|> > Riding one handed is much harder, and leads to over-correction, as
|> > other people have pointed out.
|>
|> No, it doesn't. Well, people riding one handed may be more prone to
|> overcorrection because of the emotional reaction, but that's not why
|> people crash if they hit a road obstacle riding one handed. They crash
|> because the obstacle slows or deflects the bicycle, and the momentum of
|> their body on one side of the bars causes the bar to turn. They've
|> crashed before they've had a chance to overcorrect.
Yes, it does, because the reflex action of "if the handlebars
push your hand, get it to push back, only harder" is now wrong.
With both hands on the handlebars, and appropriate damping, it
is a good way of maintaining stability. And it is THAT reflex
(which you call emotional, for some reason) that causes the
problem when riding one handed.
|> > And, of course, riding no handed means that you
|> > have no feedback through your hands, and therefore the only way
|> > that you can tell what the front wheel is doing is by the gross
|> > movements of the bicycle!
|>
|> Or by watching the stem movements, or by the lean angle of the bike as
|> felt through the saddle and pedals.
Time, time, time .... By the time that those effects are
noticeable, the front wheel may have got close to its point of
no return. The critical thing about riding with no hands is
to be able to react BEFORE that point, and it is not easy to
do. Some people can do it, but others can't.
Jon Isaacs
>facility with which they "can" do it. Face it, those who believe
>riding no-hands to be dangerous are not good at it, in fact they are
>poor at it.
>How poor is unclear but I don't know why you persist in
>making it seem like some manner of prudent caution not to ride
>no-hands.
You persist in making judgements with no knowledge.
I have yet to see a reasonable argument to justify riding "no-hands." Sure
most riders can do it, it is not much of a skill, I just see no reason to do
so.
Jon Isaacs
Jon Isaacs
>> Admittedly, it is easier to lose one's perch on a bicycle when
>> hitting large objects when riding no handed, and therefore there is
>> more chance of losing control, but it is hardly a foregone
>> conclusion that hitting an obstacle while riding no handed _will_
>> cause lose of control.
>
Jobst wrote:
>Well stated, but then we've said that often before in these discussions.
>
Well, I think we are finally getting to the bottom of this. So, riding
"no-hands" does increase the chances of going down when hitting an large
obstacle.
Now what can be said about emergency avoidance manuveuring with "no hands?"
Jon Isaacs
Bikerider
posted:
>"Bikerider" wrote:
>
>> ... The suspension fork on my bike is quite a departure from
>> that of my road machine, the front wheel axis is so closely in line
>> with the steering axis as to make the bike very 'twitchy' (poor low
>> speed castering), but also extremely maneuverable.
>
>What you describe is a fork with very little rake.
Yes, that would be another description. So would be saying that the
angular displacement between the steering axis and the center of the
front wheel's rotational axis is relatively very small on my bike,
resulting in inherent instability due to a factor strangely omitted
from the discussions, the effect of the force of gravity on stability
in relation to this displacement.
>This produces a front end with more trail, not less.
>More trail is generally said to make a bike handle
>slower and less twitchily.
But my bike does not. It's very twitchy, particularly at lower speeds,
regardless of this amount of 'trail', which should Properly be known
as "Lead", or more accurately Lead Castering since that's what it does
as far as stability is concerned. The closer the center of the wheel's
rotational axis is to the steering axis, the Poorer this castering
will be, with twitchy response being the result.
>Extreme examples are
>old bikes for motorpacing which had reversed forks
>(negative rake and extremely large trail).
I can't say I totally agree with the 'trail' diagram in:
http://www.dclxvi.org/chunk/tech/trail/
I've personally experienced that the amount of offset, or 'rake' in
the fork plays the single greatest part in stabilizing the front
wheel, aligning it to the track of the rear wheel, keeping it in line,
at any speed, allowing easy no-hands riding, particularly at lower
speeds, where the greater this offset, the greater the Lead Castering
stability, and the lesser this offset, the lesser the Lead Castering
stability thus, the greater the instability and twitchiness,
particularly at lower speeds where stability is less assisted by the
gyroscopic stability of the wheel's slower rotation.
>> Yet, once I get up
>> to speed, around 10mph or greater, I can ride it no-hands, indicating
>> that gyroscopic stability, at least every bit as much as 'trail' plays
>> a part here.
>
>Are you saying that gyroscopic stability is important
>at speeds >10 mph for all riding, not just no-hands?
No, not for all riding, only for no-hands. Gyroscopic stability,
unless deliberately countered, is innate to all spinning wheels and
will in one way or another help to stabilize a bike, even if the fork
is not designed to realize maximum effectiveness of stability from it,
such as on 'inline', twitchy steering/wheel axis alignments.
>I don't believe that your example proves this.
>At least, it hasn't been demonstrated.
I don't have access to the lab equipment to measure this but I sure
wish I did.
Eric A Holeman
Jon Isaacs <joni...@aol.com> wrote:
>I have yet to see a reasonable argument to justify riding "no-hands."
It's fun. :-P
--
---
Eric Holeman eholem1 at uic,edu
Chicago, Illinois USA
Tim McNamara
<no...@none.none> wrote:
> I believe you are directing that comment to a certain J. Isaacs. I am not
> him, I am Himm.
Oh, this has the potential for becoming Pythonesque!
Tim McNamara
<nm...@cus.cam.ac.uk> wrote:
> In article <37il7.394$bJ2....@typhoon.sonic.net>,
> jobst....@stanfordalumni.org writes:
> |>
> |> The reason you we needed to do these exercises is that you are
> |> confronting an audience that has not tried riding no-hands except for
> |> moments and who have a gory imagination of what will happen because it
> |> is an extreme hazard. Those of us who do it regularly do so on
> |> trails, fast descents and in curves and don't give it a thought. It's
> |> part of bicycling.
>
> You are quite simply wrong.
You mean he can't be riding his bike no-handed on trails, fast descents
and in curves?
> I have tried more than once, and could not maintain stability.
> In particular, the sensations though my legs are not enough to
> tell that the front wheel is starting to turn sideways.
Perhaps you are trying to use the wrong sense modalities.
> In order for an obstacle to turn the wheel significantly, it must
> be at an angle (clearly), but it must also be sudden and deep enough
> to have enough leverage to do so - and there may be more factors.
Mark's train tracks at 30 degrees don't fit the bill?
Tim McNamara
> I have yet to see a reasonable argument to justify riding "no-hands." Sure
> most riders can do it, it is not much of a skill, I just see no reason to do
> so.
Sitting up and having something to eat or drink, just changing
positions to stretch for a moment without stopping and getting off the
bike, just for fun, to look around at the scenery... there are lots of
reasons to ride no-handed.
Tim McNamara
<nm...@cus.cam.ac.uk> wrote:
> Time, time, time .... By the time that those effects are
> noticeable, the front wheel may have got close to its point of
> no return. The critical thing about riding with no hands is
> to be able to react BEFORE that point, and it is not easy to
> do. Some people can do it, but others can't.
Perhaps it is the difference between being a member of a generally
risk-averse society versus the risk-seeking mentality of the USA, or
perhaps it's road quality, or perhaps it's traffic... I don't know
what, but you persistently give the impression that the act of
bicycling is constantly on the edge of disaster. It's the same tone I
find in British cycling magazines such as Cycle Touring and Campaigning
and Cycling Plus.
I ride 5,000-7,000 miles per year and have done for decades, including
racing regularly over the past 10 years, and my last crash was in 1994.
Bicycling is just not the constant crisis-avoidance festival of fear
that you are implying in your posts.
jobst....@stanfordalumni.org
> Registration is not the whole task - analysis is! The note (bill)
> test is indicative - you know the one where you hold your fingers an
> inch or so either side of a note held vertically by someone else and
> you try and catch it as it drops. You have a WHOLE 0.2 seconds in
> which to catch it, and most people can't - I can, still.
> As I understand it, non-trivial vision tasks (i.e. ones that don't
> have hard-wired circuitry in the brain) take more like 0.1 seconds;
> the smaller figure is only for ones that have specific neural
> circuits. But, yes, even for the latter, you will REGISTER the
> sight - what you will not have done is converted it into a concept.
> ...
This is getting long tedious and belaboring the obvious as we often do
on wreck.bike, gradually changing the argument so that victory can be
claimed albeit on a change of venue. What I see here is another
treatise on why bumble bees cannot fly.
The fact is that most young and young minded athletes ride no hands
often as part of normal bicycling and do so on rough roads as well as
smooth. All the dire warnings about crashing are just so much
blather. People don't crash from riding no-hands and those that do
don't continue doing it.
We don't need no steenkin road tests and proofs. No-hands riding
exists and is done often by those who master the skill. The excuses I
hear are like the bicyclist who explains why he got dropped on a hill
by "I could have gone faster but I didn't want to" BS!
Jobst Brandt <jobst....@stanfordalumni.org>
Nick Maclaren
In article <X3vl7.530$bJ2....@typhoon.sonic.net>,
jobst....@stanfordalumni.org writes:
|>
|> This is getting long tedious and belaboring the obvious as we often do
|> on wreck.bike, gradually changing the argument so that victory can be
|> claimed albeit on a change of venue. What I see here is another
|> treatise on why bumble bees cannot fly.
Absolute nonsense, as you point out below.
|> The fact is that most young and young minded athletes ride no hands
|> often as part of normal bicycling and do so on rough roads as well as
|> smooth. All the dire warnings about crashing are just so much
|> blather. People don't crash from riding no-hands and those that do
|> don't continue doing it.
Your first sentence is, indeed, correct. But it does NOT imply
(as you and other people have claimed) that it means that most people
can ride with no hands if they try. Most people are not athletes,
and a great many could not become athletes however hard they try.
Nick Maclaren
In article <050920011242196202%tim...@mac.com>,
Tim McNamara <tim...@mac.com> writes:
|> In article <9n54rt$9lj$1...@pegasus.csx.cam.ac.uk>, Nick Maclaren
|> <nm...@cus.cam.ac.uk> wrote:
|> > In article <37il7.394$bJ2....@typhoon.sonic.net>,
|> > jobst....@stanfordalumni.org writes:
|> > |>
|> > |> The reason you we needed to do these exercises is that you are
|> > |> confronting an audience that has not tried riding no-hands except for
|> > |> moments and who have a gory imagination of what will happen because it
|> > |> is an extreme hazard. Those of us who do it regularly do so on
|> > |> trails, fast descents and in curves and don't give it a thought. It's
|> > |> part of bicycling.
|> >
|> > You are quite simply wrong.
|>
|> You mean he can't be riding his bike no-handed on trails, fast descents
|> and in curves?
No - he is wrong in claiming that the audience has not tried except
for moments and that the dangers are due to imagination. I have
tried, and my perceptions of its effects on other people are due
to observation.
|> > I have tried more than once, and could not maintain stability.
|> > In particular, the sensations though my legs are not enough to
|> > tell that the front wheel is starting to turn sideways.
|>
|> Perhaps you are trying to use the wrong sense modalities.
Naturally, but how do you suggest that I use modalities that I
don't have? Ideas are welcomed :-)
|> > In order for an obstacle to turn the wheel significantly, it must
|> > be at an angle (clearly), but it must also be sudden and deep enough
|> > to have enough leverage to do so - and there may be more factors.
|>
|> Mark's train tracks at 30 degrees don't fit the bill?
No, for reasons I gave. I have tried precisely that experiment
myself and, for reasons I don't understand, they don't seem to
twist the wheel sideways. At least usually. Yet SOME road
problems do, because I have felt the effect.
Trevor Jeffrey
(Jon Isaacs) writes:
>Now what can be said about emergency avoidance manuveuring with "no hands?"
Shake your hips left, shake your hips right. Or use your thigh to bang the top
tube for a smaller deflection. When someone rides no hands, he learns.
--
Don't argue, debate, it sounds so much better.
Eat your greens before email.
------
Trevor Jeffrey
Eating and drinking.
Stretching spine.
Looking over other riders or general traffic especially backwards.
Because I can.
Changing clothing.
Having a punch up.
'Cause it looks really cool when I pull off a wheely at the same time.
I consider all the above to almost necessitate riding no hands, they can all be
done one handed, but are better done with both. Try and do an emergency stop
with one hand. At least from an upright position, when returning to the 'bars
there wont be any steering effect. When riding one handed the bike is skewed
because of the weight transfer on the held bar, hit a bump and there's some
steering wobble.
In fact the only time holding handlebars becomes essential is when using the
brake levers.
Perception of reasonable is relative to each individuaal.
In article <20010905083629...@mb-fa.aol.com>, joni...@aol.com
(Jon Isaacs) writes:
>I have yet to see a reasonable argument to justify riding "no-hands." Sure
>most riders can do it, it is not much of a skill, I just see no reason to do
>so.
>
It's safer than riding with one hand. The only one handed riding necessary is
when assisting another rider up a hill or through a turn, holding middle
section of bars.
Trevor Jeffrey
crashes have happened with hands firmly attached to handlebars. A good
awareness of what's around you, correct analysis and proper application of
that knowledge will do much more in assisting safety than any brake, helmet or
handlebar hold put together.
In article <X3vl7.530$bJ2....@typhoon.sonic.net>,
jobst....@stanfordalumni.org writes:
> People don't crash from riding no-hands and those that do
>don't continue doing it.
>
Application of this reasoning would in my position, have me riding no hands all
the time or should that be one handed. Next time I fall/or crash I'll sell up,
sounds like it's all getting too complicated.
It's the same with cars, its all down to the operator. Automatic gears
and airbags just encourage poor driving, stick a spike out of that steering
hub, make it risky for the driver and give room on the roads for proper driving
and riding for those who can do it right.