Precession Video

Philip Holman said:

http://www.rci.rutgers.edu/%7Ewilliebo/zzzgyrovideo.MPG

This is a good demonstration of how the torque on the end of the axle is
converted to rotation of the wheel around the vertical string. Requires
Windows media player or similar to run. Please, no thread drift into
gyroscopic stability as a major contributor to rider balance.

PH

Dear Phil,

Aha! This makes it clear what Simon Brooke and the rest of
you were trying to explain to me last year.

Thanks,

Carl Fogel

Philip Holman said:

http://www.rci.rutgers.edu/%7Ewilliebo/zzzgyrovideo.MPG

This is a good demonstration of how the torque on the end of the axle is
converted to rotation of the wheel around the vertical string. Requires
Windows media player or similar to run. Please, no thread drift into
gyroscopic stability as a major contributor to rider balance.

PH

A torque applied to the axle will effect the wheel 90 degrees away in
the direction of rotation. IE... You try to turn the wheel, it will
tilt. Tilt it and it will turn. This is why countersteering works.
Any 1st year Navy Gyro tech should know this. 🙂

--
Mark Wolfe Lakeside, ca http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
In this talk, I would like to speculate a little, on ... the development
of intelligent life. I shall take this to include the human race, even
though much of its behaviour throughout history has been pretty
stupid... - Stephen Hawking

"Mark Wolfe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

A torque applied to the axle will effect the wheel 90 degrees away in
the direction of rotation. IE... You try to turn the wheel, it will
tilt. Tilt it and it will turn. This is why countersteering works.
Any 1st year Navy Gyro tech should know this. 🙂

I think it more is how no-hands steering works.

Peter Cole said:

"Mark Wolfe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

A torque applied to the axle will effect the wheel 90 degrees away
in the direction of rotation. IE... You try to turn the wheel, it
will tilt. Tilt it and it will turn. This is why countersteering
works. Any 1st year Navy Gyro tech should know this. 🙂

I think it more is how no-hands steering works.

http://draco.acs.uci.edu/rbfaq/FAQ/9.35.html

Subject: 9.35 Gyroscopic Forces From: Jobst Brandt
<[email hidden]> Date: Fri, 13 Feb 2004 12:07:59
-0800

<...>

Those who ride no-hands sense and make use of the small gyroscopic
effect of the front wheel to steer.

<...>

"Peter Cole" <[email hidden]> wrote in message news:<ibSld.32300$V41.22876@attbi_s52>...

Quoted message said:

"Mark Wolfe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

A torque applied to the axle will effect the wheel 90 degrees away in
the direction of rotation. IE... You try to turn the wheel, it will
tilt. Tilt it and it will turn. This is why countersteering works.
Any 1st year Navy Gyro tech should know this. 🙂

I think it more is how no-hands steering works.

OK, so who thinks this bike:
http://www2.bitstream.net/~dkrafft/icebike/icepics/brick00.jpg
(from http://www2.bitstream.net/~dkrafft/icebike/Ice99.html)
could be ridden no-hands?

Jeff

Jeff Wills said:

"Peter Cole" <[email hidden]> wrote in message news:<ibSld.32300$V41.22876@attbi_s52>...

Quoted message said:

"Mark Wolfe" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

A torque applied to the axle will effect the wheel 90 degrees away in
the direction of rotation. IE... You try to turn the wheel, it will
tilt. Tilt it and it will turn. This is why countersteering works.
Any 1st year Navy Gyro tech should know this. 🙂

I think it more is how no-hands steering works.

OK, so who thinks this bike:
http://www2.bitstream.net/~dkrafft/icebike/icepics/brick00.jpg
(from http://www2.bitstream.net/~dkrafft/icebike/Ice99.html)
could be ridden no-hands?

Jeff

not sure about that particular machine, but other ice/ski "bikes" can
easily be ridden no hands. the illusion that stability is purely a
function of gyro forces is just that; an illusion.

as mark says, gyros have a reaction at 90 degrees to any turning force -
which is why the gyro in the video rotates about the string suspension
point.

Mark Wolfe said:

A torque applied to the axle will effect the wheel 90 degrees away
in the direction of rotation. IE... You try to turn the wheel, it
will tilt. Tilt it and it will turn. This is why countersteering
works. Any 1st year Navy Gyro tech should know this.

"This is why countersteering works." Please explain what you mean by
"works" and what you perceive countersteering has to do with
gyroscopic forces. Just to restate what has been said:

# Countersteer is a popular subject for people who belatedly discover
# or rediscover how to balance. What is not apparent, is that two
# wheeled vehicles can be controlled ONLY by countersteer, there is no
# other way. Unlike a car, a bicycle cannot be diverted from a
# straight path by steering the wheel to one side. The bicycle must
# first be leaned in that direction by steering it ever so slightly
# the other way. This is the means by which a broomstick is balanced
# on the palm of the hand or a bicycle on the road. The point of
# support is moved beneath the mass, in line with the combined forces
# of gravity and cornering, and it requires steering, counter and
# otherwise. It is so obvious that runners never mention it, although
# football, basketball, and ice hockey players conspicuously do it.

Jobst Brandt
[email hidden]

jim beam said:

Jeff Wills said:

"Peter Cole" <[email hidden]> wrote in
message news:<ibSld.32300$V41.22876@attbi_s52>...

Quoted message said:

"Mark Wolfe" <[email hidden]> wrote in message
news:[email hidden]...

>A torque applied to the axle will effect the wheel 90 degrees away
>in the direction of rotation. IE... You try to turn the wheel,
>it will tilt. Tilt it and it will turn. This is why
>countersteering works. Any 1st year Navy Gyro tech should know
>this. 🙂

I think it more is how no-hands steering works.

OK, so who thinks this bike:
http://www2.bitstream.net/~dkrafft/icebike/icepics/brick00.jpg
(from http://www2.bitstream.net/~dkrafft/icebike/Ice99.html) could
be ridden no-hands? Jeff

not sure about that particular machine, but other ice/ski "bikes"
can easily be ridden no hands. the illusion that stability is
purely a function of gyro forces is just that; an illusion.

I don't hear anyone in this thread arguing that stability is purely a
function of gyro forces, although that claim is certainly perennial in
r.b.t. and no doubt will come up again!

However, can a vehicle with poorly defined trail (where does one
measure when the contact patch is 8 inches long?) and no gyroscopic
forces be ridden in anything other than a straight line no-handed?
One can ride a bike no handed and weave back and forth between the
dashed lane markers- can this be done on a contraption such as the one
pictured? (I live near these lunatics, I should go out to next
winter's event and see if I can test ride some of these things. It'd
be fun. Mark Stonich is a great guy, unafraid to experiment and very
creative).

The mathematics of bike handling don't seem to be entirely worked out,
though. Trail is currently emphasized in the discussion about
stability, thanks to Jones' published work in particular, but all
bikes with equal trail do not handle the same. For example, a bike
with a 71 degree head tube and one with 74 degree head tube handle
differently, even if trail is the same.