
Gyrocar - m3at
https://en.wikipedia.org/wiki/Gyrocar
======
NamTaf
If you're ever in York in the UK, there's a cool model of Brennan's Gyrostatic
monorail car in the National Railway Museum. I had no idea about gyrocars
before that and was blown away by the technical prowess of the design from the
early 1900s. His wasn't an automobile as such, but rather a rail vehicle that
operated on a single rail, just like a monorail.

His actually pre-dates this, with him patenting the design in 1903, developing
a working model in 'about 1907' (according to my photos of the display) and a
full-sized one in 1909. That suggests, assuming the parent wiki is correct,
that the idea of a gyro automobile was described in fantasy _after_ a gyro
rail vehicle was fully developed. I find it quite interesting that it took
that long for the idea to leap from one mode of transport to the other, and it
probably speaks to how unfamiliar the automobile was as a concept even in the
first decade of the 1900s.

His wiki [1] provides a bit more info, and links to the article on the gyro
monorail car [2] with a wealth of detailed information about the design (much
of which maps to the gyrocar).

Fascinating design.

[1]:
[https://en.wikipedia.org/wiki/Louis_Brennan](https://en.wikipedia.org/wiki/Louis_Brennan)
[2]:
[https://en.wikipedia.org/wiki/Gyro_monorail](https://en.wikipedia.org/wiki/Gyro_monorail)

~~~
erk__
It was the first thing I thought of when I saw the title, visited the museum
earlier this year, the model is a bit hidden in the back of the museum. It is
a great museum and they have so many interesting things there.

------
seanhunter
It's a fascinating design, but "Why?" is the question that leaps to mind. Once
you get above a certain mass it just seems really beneficial to have a design
that is stable at rest. (I'm speaking as someone who has had to pick up heavy
motorcycles which have fallen or been knocked over a few times)

So what's the benefit of a Gyrocar to compensate for that? A motorbike has the
benefit of really dynamic performance coming from the ability to lean in to
corners etc, but it seems to me that this thing would work more like a
tricycle (ie no countersteer or lean) because the gyroscopes would keep the
body of the car level.

~~~
ff317
A motorbike will generally both accelerate and brake faster than a car in a
straight line (mostly because it's light), but actually loses on cornering
speeds against a four-wheeled car because the bike doesn't have as much
lateral grip.

~~~
YSFEJ4SWJUVU6
>A motorbike will generally [...] brake faster than a car in a straight line
(mostly because it's light)

That's generally not true. At best you'd roughly match an average car when
balancing your weight perfectly; but typically you can only expect worse
results when comparing the two.

~~~
nwallin
Classical equations of friction gives a constant relationship between weight
and maximum acceleration from friction. And that applies fairly well to most
pairs of materials.

But it applies less well to rubber. Rubber has significant natural adhesive
qualities, so a normal force of zero Newtons gives a non zero acceleration.
This adhesion dominates low weight acceleration. This is why performance cars
tend to have larger tires. See dragsters for the logical conclusion. Without
that adhesive quality, performance cars would prefer smaller tires for reduced
air resistance.

The classical coefficient of friction model is one of "spherical frictionless
cows in a vacuum" white lies we tell students to prevent them from getting
overwhelmed by the hairiest differential equations imaginable.

------
m3at
The wikipedia article is a bit short on pictures, so here are more of this
very interesting design:
[https://www.lanemotormuseum.org/collection/cars/item/gyro-x-...](https://www.lanemotormuseum.org/collection/cars/item/gyro-x-1967)

------
newnewpdro
> Steering a motorcycle is done by precessing the front wheel.

I've encountered this claim so many times over the years. The precession force
I've observed when riding motorcycles, by moving the bars after the front
wheel leaves the ground, is simply not that great. It's obviously not the
primary force steering a motorcycle.

With the front tire in contact with the road, motorcycles can _appear_ to
steer from precession because they initiate turns unintuitively via inverted
counter-steering. What's really happening is when you initiate a turn, the
point at the road:tire interface immediately veers in the direction you
pointed because of the tire's grip with the road. But since this point is well
below the center of gravity of the motorcycle, instead of steering the entire
bike in that direction, the bike falls down and leans in the opposite
direction. Thanks to the angle of the fork there's a complementary geometric
relationship between the bike's lean angle and the front wheel's steering
angle in the direction of the lean. These are the primary mechanisms steering
a motorcycle.

The same mechanism is present in automobiles, which also have a significant
distance separating the road:tire interface from the center of gravity. But in
those vehicles it's exhibited as body roll, which is then necessarily resisted
by the suspension components like springs and anti-sway bars. Nobody claims
precession causes automobile body roll, because it's more obvious what's going
on there - and the driver doesn't steer backwards briefly at the start of
every turn.

Precession is a fun demonstration in science class, and does enable a
motorcycle rider to exert _some_ control when on one wheel. But it simply
isn't the primary mechanism steering a motorcycle.

------
et2o
These are pretty cool. Lit Motors in the Bay Area has a modern take on the
same idea: [https://youtu.be/JMYdUwUVE6w](https://youtu.be/JMYdUwUVE6w)

~~~
FR10
Sadly that is from 2013, I wonder what is the reason it didn't get developed
further.

~~~
52-6F-62
Not sure. It was hard to find more info. It appears Danny Kim was in a pretty
serious test-track accident:

[https://www.forbes.com/sites/lianeyvkoff/2016/02/18/what-
imm...](https://www.forbes.com/sites/lianeyvkoff/2016/02/18/what-immobility-
taught-this-transportation-ceo-about-mobility/#44db249058c4)

------
nsxwolf
Do the wheels really add gyroscopic effects? Some years ago the revelation
that gyroscopic effects weren't what keep a bicycle up rocked the world, then
everyone seemed to forget about that and talks about gyroscopic effects again.
Is that the case here?

~~~
caconym_
I don't know if it really "rocked the world". Probably most people never heard
it or discounted it as soon as they did because they "knew" it was wrong.

Motorcycle wheels are heavier and spin faster, so I'd expect the gyroscopic
forces to be greater at speed, but the fact that you can go walking speed (or
slower) on a motorcycle without falling over seems to disprove gyroscopic
effects as a primary factor in stability.

~~~
dredmorbius
There are different modes of stability for wheeled vehicles. Gyroscopic
effects are far more significant at speed. Though the ability to steer into a
fall and move centre of gravity under centre of support is a key dynamic,
particularly at low (or no) speed.

------
ScottBurson
How can Wikipedia have a gyrocar article and not mention the Gyro-X??
[https://www.lanemotormuseum.org/collection/cars/item/gyro-x-...](https://www.lanemotormuseum.org/collection/cars/item/gyro-x-1967)

[https://www.wired.com/story/gyro-x-lane-motor-
museum/](https://www.wired.com/story/gyro-x-lane-motor-museum/)

~~~
dredmorbius
It's a Wiki. It's editable. By you.

~~~
ScottBurson
Sorry, no time.

------
innovator116
There was a Chinese knockoff of Lit Motors. Been following
[https://thrustcycle.com/index.html](https://thrustcycle.com/index.html) An
Indian startup [http://www.ligermobility.com/](http://www.ligermobility.com/)
is also developing self balancing EV for crowded Indian cities.

------
msadowski
Recently there was a project on Hackaday where someone created an R/C gyrocar:
[https://hackaday.com/2019/09/06/who-needs-four-wheels-
when-y...](https://hackaday.com/2019/09/06/who-needs-four-wheels-when-youve-
got-a-gyro/)

The project is quite neat!

------
dang
Related from 2016:
[https://news.ycombinator.com/item?id=10852421](https://news.ycombinator.com/item?id=10852421)

2015:
[https://news.ycombinator.com/item?id=10611187](https://news.ycombinator.com/item?id=10611187)

------
agumonkey
Not to be confused with
[https://en.wikipedia.org/wiki/Gyrobus](https://en.wikipedia.org/wiki/Gyrobus)

~~~
mr__y
Also not to be confused with
[https://en.wikipedia.org/wiki/Gyro_(food)](https://en.wikipedia.org/wiki/Gyro_\(food\))

~~~
alfanick
Also to be confused with
[https://en.wikipedia.org/wiki/Gyros](https://en.wikipedia.org/wiki/Gyros)

~~~
dredmorbius
All etymologically linked to the Greek _γύρος_ and ultimately PIE "*geu-".

In the case of the Greek wrap, the reference isn't to the "rounded" pita
shell, but the "turned" meat, roasted on a spit.

[https://www.etymonline.com/word/gyre](https://www.etymonline.com/word/gyre)

[https://www.etymonline.com/word/gyro-](https://www.etymonline.com/word/gyro-)

------
headgasket
why not use the mass of the battery as the gyro's flywheel (s)? You could also
store energy (accelerate this mass on breaking) for even better regen (I
presume recharge breaking is less efficient than the 95 efficiency of current
traction motors).

Another plus is easier ajustable ground clearance since there's only 2 points
of contact; for an off-road-able vehicle that's a big plus; while at highway
speeds you want a low center of gravity and less drag.

Will we see a 2 wheeled pickup truck reveal tomorrow? A BUV? (Battery Ultimate
Vehicle) That would be "cyber from the future" alright. Dreaming out loud, but
a ppl carrier (8-10 seater based on this would be totally out of this world)

~~~
bediger4000
> why not use the mass of the battery as the gyro's flywheel (s)? I'm going to
> guess that the battery technology of 1912 was lead-acid. 200 lbs of sulfuric
> acid spinning at 3600 RPM was probably too much of a safety hazard, even for
> the laissez-faire standards of the day. Also, slip rings, which would be
> necessary to get the current out of a spinning batter probably weren't all
> that good.

~~~
headgasket
good points with regards to 1912. But li-ion batteries that are also gyro
flywheels, and breaking regen energy storage, isn't that an interesting idea?

------
trhway
one wheel bikes
[https://www.youtube.com/watch?v=_eVbdbMPdq4](https://www.youtube.com/watch?v=_eVbdbMPdq4)

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themagician
This just seems like a motorcycle with extra steps.

