How do we stay upright on a 'bent?

Some people seem to need reminders- if you cannot keep your mind on
bicycle balance, how can you ride a 'bent?:
How in the world do we stay upright on a bicycle? Many have supposed
that gyroscopic forces from spinning wheels are responsible. However,
somebody finally went to the trouble to figure out what's going on. At
the University of Cambridge, Dr Hugh Hunt ran some experiments to see
how different bike designs affect balance. The results are pretty
complicated, but let's just say that gyroscopic forces aren't that
important. If you love science, check out Dr Hunt's report at the
University of Cambridge Website. You can see the math behind his study
and move on to more discussions on the science of staying upright. If
that stuff doesn't interest you, just remember to keep the rubber side
down while you're riding. Thanks to The Bike Blog.

wrote:
Some people seem to need reminders- if you cannot keep your mind on
bicycle balance, how can you ride a 'bent?:
How in the world do we stay upright on a bicycle? Many have supposed
that gyroscopic forces from spinning wheels are responsible. However,
somebody finally went to the trouble to figure out what's going on. At
the University of Cambridge, Dr Hugh Hunt ran some experiments to see
how different bike designs affect balance. The results are pretty
complicated, but let's just say that gyroscopic forces aren't that
important. If you love science, check out Dr Hunt's report at the
University of Cambridge Website. You can see the math behind his study
and move on to more discussions on the science of staying upright. If
that stuff doesn't interest you, just remember to keep the rubber side
down while you're riding. Thanks to The Bike Blog.





















this is the link : http://www2.eng.cam.ac.uk/~hemh/gyrobike.htm
Theroretically almost the same leaning concept on a 'bent, but I
cannot figure out if this also applies to a lean-steering trike,
thereby allowing the "no hands" riding.

On Wed, 14 Feb 2007 18:26:00 -0800, eco_milage_buster_2005 wrote:


How in the world do we stay upright on a bicycle? Many have supposed
that gyroscopic forces from spinning wheels are responsible. However,
somebody finally went to the trouble to figure out what's going on.

The classic study of bicycles is David Jones' "The stability of the
bicycle" in Physics Today, 1970. He reached the same conclusions about
gyroscopic forces, and tried many more geometries for the steering too.
His report, as a scan of the original article on paper, is here (8Mb):
http://socrates.berkeley.edu/~fajans...onesBikeBW.pdf
and there's a 2006 reprint (1.5Mb) he
http://www.phys.lsu.edu/faculty/gonz...9no9p51_56.pdf



Mike

wrote:
Some people seem to need reminders- if you cannot keep your mind on
bicycle balance, how can you ride a 'bent?:

I get quite a few "how do you do X?" questions. More often than
not the answer is "pretty much the same as I do it on an upright
bike". As well as balance I often get starting, particularly hill
starts, and (rather bizarrely ISTM) steering.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

In alt.rec.bicycles.recumbent on Thu, 15 Feb 2007 19:23:59 +0000
Peter Clinch wrote:
wrote:
Some people seem to need reminders- if you cannot keep your mind on
bicycle balance, how can you ride a 'bent?:

I get quite a few "how do you do X?" questions. More often than
not the answer is "pretty much the same as I do it on an upright
bike". As well as balance I often get starting, particularly hill
starts, and (rather bizarrely ISTM) steering.


The steering one seems to be because most people don't know how a
single track vehicle steers. Despite riding one for years if you ask
them they'll say you turn the bars....

Motorcycle training classes usually teach countersteering because many
riders don't realise it is happening, and don't realise why it's
important to know about it. It's less important on pushbikes as the
speeds are slower and you don't need the serious steering input to get
round corners in the same way.

(Although you might on a bent, as you can lean more. The skinny tyres
probably limit lean angle though, so the fast transition from upright
to leaned isn't as useful.)

I now can demonstrate a smooth easy start, when I first got the bike
starting was tricky. Practice fixed that, and now I do it without
thinking.

I get "how do you pedal that?" from kids a lot (when it's not "wow!
Really cool bike!") and my usual answer is "put my feet on the pedals
and push". Adults are usually "that looks comfortable" from
non-cyclists and "how heavy is it?" from cyclists. Cyclists also say
"you haven't got a flag, you can't be seen in traffic!" which is a
really bizzare thing to say to a high BB bike rider and to me a sign
that the speaker hasn't actually *thought* about road safety.

NOt that that should surprise me, the number of people who have is
depressingly small. And, alas, includes a hell of a lot of road
designers and media pundits...

Zebee

Zebee Johnstone wrote:

The steering one seems to be because most people don't know how a
single track vehicle steers. Despite riding one for years if you ask
them they'll say you turn the bars....

Though this is true, it's also true that they /don't/ ask the same
question of an upright, even the one they happen to be astride when they
ask the question!

Adults are usually "that looks comfortable" from non-cyclists

Though oddly I occasionally get "that _cannot_ be comfortable". You ask
some leading questions and it soon becomes evident that "different ==
wrong".

Cyclists also say
"you haven't got a flag, you can't be seen in traffic!" which is a
really bizzare thing to say to a high BB bike rider and to me a sign
that the speaker hasn't actually *thought* about road safety.

I get told I must be invisible and feel vulnerable being so low more
than most other comments. I point out I'm the same height as a car
driver, sometimes roll up by a car to prove it, but again as often as
not the mind cannot be confused with facts because it has already been
made up!

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

In alt.rec.bicycles.recumbent on Fri, 16 Feb 2007 08:29:34 +0000
Peter Clinch wrote:
Zebee Johnstone wrote:

The steering one seems to be because most people don't know how a
single track vehicle steers. Despite riding one for years if you ask
them they'll say you turn the bars....

Though this is true, it's also true that they /don't/ ask the same
question of an upright, even the one they happen to be astride when they
ask the question!

yup. the familiar is accepted, the unfamiliar must be different in
all respects.

Adults are usually "that looks comfortable" from non-cyclists

Though oddly I occasionally get "that _cannot_ be comfortable". You ask
some leading questions and it soon becomes evident that "different ==
wrong".

yes, I've had that too. Because they can't say why they think that,
but it was an instant feeling. I tend to say "I'm relaxing back in a
lounge chair, how can it be uncomforable?"

I get told I must be invisible and feel vulnerable being so low more
than most other comments. I point out I'm the same height as a car
driver, sometimes roll up by a car to prove it, but again as often as
not the mind cannot be confused with facts because it has already been
made up!


Yup. The one I thought funny was the courier who chased after me to
say I must get a flag because his 14 years of experience said so, and
that he didn't have time to argue.

It wasn't clear what his 14 years of experience was in, I doubt it was
riding bents in traffic, nor indeed of road safety research. I did
have to wonder just what he thought was useful about something that
was out of a driver's line of sight, but I dunno "think" was in the
frame really.

My suspicion is that *he* was uncomfortable because some cyclists
assume that if they can't see something on the other side of a car
then it is safe to dart in front of that car if it's going slowly
enough. Even if there's a full lane on the other side of the car.

Hope they don't meet any Fiat Lombardis. The one we had had a
roof that was about 4" above the doorsill of your average HQ Holden
(1970s Australian sedan, utterly ubiquitous) and shorter than most.
Completely hidden by most family cars. A Mini Minor, new or old, is
hidden by most big 4WDs. So if that was his idea then he's going to
have to rethink those 14 years I reckon.

Zebee
- who usually gets plenty of room from drivers, and carries on
conversations with them at the lights.