Recumbents

Doki said:

Does anyone make a FWD / rear steer recumbent?

FWD, certainly. Zox and Flevo are the obvious examples, plus the Very
Serious Speed machinery used at the likes of Battle Mountain is
sometimes FWD (well, it's not like they have to go round hairpin bends...).

Rear steer is a different matter. I think it was in C+ that someone
asked this and Mike Burrows answered it. IIRC he basically said that
what's fine in theory doesn't work quite so well in practice and rear
steer bikes tend to be patronised by people called Koko with large red
noses...

The Flevo is an interesting exception to the usual rules: it doesn't
steer at either wheel but has a hinge in the middle of the bike, and can
be ridden completely no hands as far as steering goes (though bars are
provided to mount brake and gear levers)

Quoted message said:

Seems to me you'd save a lot
of chain length. Perhaps they'd struggle for grip up hills?

I believe that is an issue with some, though not bad enough to render
the concept useless. I think it's combining the steering with the drive
that causes more headaches.

OTOH, long chains aren't as bad as you might think: less wear when used
on derailleurs, for example, as the angles aren't so bad as you move
across the cassette.

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 [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Rear steer is a different matter. I think it was in C+ that someone
asked this and Mike Burrows answered it. IIRC he basically said that
what's fine in theory doesn't work quite so well in practice and rear
steer bikes tend to be patronised by people called Koko with large red
noses...

I was just thinking about this and considering what pushing a rear steer
trolley is like. There is only one word I can think of to desribe the
thought of rear wheel steering on a fast downhill and that is SCARY
(followed by lots of road rash and a stay in hospital).

There is a reason the back wheels follow the front and that is stability.
Rear steering involves the back going it's own way. Interesting...

...d

David Martin said:

I was just thinking about this and considering what pushing a rear
steer trolley is like. There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

ISTR that Thrust SSC was rear-steer.

--
Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

On 21/6/04 4:34 pm, in article [email hidden], "Just zis Guy,

you know? said:

David Martin said:

I was just thinking about this and considering what pushing a rear
steer trolley is like. There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

ISTR that Thrust SSC was rear-steer.

For limited values of steer, yes. To get sufficient turning circle you would
need a reasonable degree of rotation on the steered wheel. Thrust type
steering would be fine if there were no corners.

...d

David Martin said:

On 21/6/04 3:56 pm, in article [email hidden], "Peter

Clinch said:

Rear steer is a different matter. I think it was in C+ that someone
asked this and Mike Burrows answered it. IIRC he basically said that
what's fine in theory doesn't work quite so well in practice and rear
steer bikes tend to be patronised by people called Koko with large
red noses...

I was just thinking about this and considering what pushing a rear
steer trolley is like.

Just a case of practice, IME of pushing trolleys with the steering wheels at
the back.

Quoted message said:

There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

There is a reason the back wheels follow the front and that is
stability. Rear steering involves the back going it's own way.
Interesting...

It wouldn't be difficult to castor the rear wheels so that they return to
straight ahead of their own accord. The opposite occurs in a car when you
reverse, so it gives you the impression that rear steer is much more
unstable than it has to be.

Just zis Guy, you know? typed:

Quoted message said:

David Martin said:

I was just thinking about this and considering what pushing a rear
steer trolley is like. There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

ISTR that Thrust SSC was rear-steer.

But Thrust doesn't have 'steering' as such, it's really just an aid to
staying in a straight line at st00pid speeds ... 😉

--
Paul ...

(8(|) ... Homer Rocks

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

Quoted message said:

David Martin said:

On 21/6/04 3:56 pm, in article [email hidden], "Peter

Clinch said:

Rear steer is a different matter. I think it was in C+ that someone
asked this and Mike Burrows answered it. IIRC he basically said that
what's fine in theory doesn't work quite so well in practice and rear
steer bikes tend to be patronised by people called Koko with large
red noses...

I was just thinking about this and considering what pushing a rear
steer trolley is like.

Just a case of practice, IME of pushing trolleys with the steering wheels at
the back.

Do you actually know of any documented case of someone being able to ride a
rear-steered bicycle?

All the experiments I have read of have concluded that it's pretty much
impossible.

It could easily be built into tricycles if you wanted to though.

Quoted message said:

Quoted message said:

There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

There is a reason the back wheels follow the front and that is
stability. Rear steering involves the back going it's own way.
Interesting...

The problem is that to turn away from an obstacle you have to steer towards it.
This means that situations can arise where it is not possible to avoid the
obstacle with rear steering but it could have been avoided with front steering.

Quoted message said:

It wouldn't be difficult to castor the rear wheels so that they return to
straight ahead of their own accord. The opposite occurs in a car when you
reverse, so it gives you the impression that rear steer is much more
unstable than it has to be.

Very few HPVs have reverse gears[1], so the necessary corrections possible with
a car are not available.

[1] Yes, I know there are a few.
--
Mark South: World Citizen, Net Denizen

Mark South said:

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

Quoted message said:

David Martin said:

On 21/6/04 3:56 pm, in article [email hidden], "Peter
Clinch" <[email hidden]> wrote:

> Rear steer is a different matter. I think it was in C+ that
> someone asked this and Mike Burrows answered it. IIRC he
> basically said that what's fine in theory doesn't work quite so
> well in practice and rear steer bikes tend to be patronised by
> people called Koko with large red noses...

I was just thinking about this and considering what pushing a rear
steer trolley is like.

Just a case of practice, IME of pushing trolleys with the steering
wheels at the back.

Do you actually know of any documented case of someone being able to
ride a rear-steered bicycle?

All the experiments I have read of have concluded that it's pretty
much impossible.

It could easily be built into tricycles if you wanted to though.

I was thinking of a pair of rear wheels TBH. I've not tried it, or read up
on. I wouldn't even want to try riding a rear steer bicycle, too much weight
over the wheel that's lurching across the road quite rapidly...

Quoted message said:

Quoted message said:

Quoted message said:

There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in
hospital).

There is a reason the back wheels follow the front and that is
stability. Rear steering involves the back going it's own way.
Interesting...

The problem is that to turn away from an obstacle you have to steer
towards it. This means that situations can arise where it is not
possible to avoid the obstacle with rear steering but it could have
been avoided with front steering.

I'm afraid I don't really *get* countersteering. I must do it, but I've
never noticed myself do it. Probably all bunged away in the brain stem and
never consciously thought about.

Quoted message said:

Quoted message said:

It wouldn't be difficult to castor the rear wheels so that they
return to straight ahead of their own accord. The opposite occurs in
a car when you reverse, so it gives you the impression that rear
steer is much more unstable than it has to be.

Very few HPVs have reverse gears[1], so the necessary corrections
possible with a car are not available.

[1] Yes, I know there are a few.

I wasn't thinking of having a reverse gear on the bike, just that if you
ever try reversing at speed in a car, the slightest steering input results
in the car winding a lot of lock on by itself. The same effect gives the
steering self centring when you're going forwards.

Mark South said:

Do you actually know of any documented case of someone being able to ride a
rear-steered bicycle?

All the experiments I have read of have concluded that it's pretty much
impossible.

I've ridden rear steer bikes. Once you get the hang of it it's pretty
easy, though I haven't ridden them at any great speed.

Actually, come to think of it, the bikes I'm thinking of have 2 wheel
steering. So it's not the same thing at all:
<URL:http://www.unicycle.uk.com/shop/shopdisplayproduct.asp?catalogid=263>

--
Danny Colyer (the UK company has been laughed out of my reply address)
<URL:http://www.speedy5.freeserve.co.uk/danny/>
"He who dares not offend cannot be honest." - Thomas Paine

you know? said:

David Martin said:

I was just thinking about this and considering what pushing a rear
steer trolley is like. There is only one word I can think of to
desribe the thought of rear wheel steering on a fast downhill and
that is SCARY (followed by lots of road rash and a stay in hospital).

ISTR that Thrust SSC was rear-steer.

It was, and when teh engineers proposed it as teh solution to various
problems it was mightily poo-pooed. It'll never work, inherently
unstable, blaah blaah. In fact, read on in the thread for the sort of
comments heaped on teh rear-steer proposal.

They built a steering prototype by taking a mini, locking teh front
wheels straight, detaching teh back axle and substituting a long pylon
with steering wheels on teh back, such that the geometry was a
scaled-down version of the Thrust proposal.

Apparently it steered beautifully, no problem at all, as long all teh
linkages were fully 100% ok and there was no slop in anything.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

Doki said:

Does anyone make a FWD / rear steer recumbent? Seems to me you'd save a lot
of chain length. Perhaps they'd struggle for grip up hills?

There are FWD,FWS tadpole trikes - russian titanium ones turn up
occasionally.

There's also one that is FWD via a differential, and steered by
braking teh front wheels individually, like a tank. The back wheel is
just a castor. I quite like that as a scheme, but I don't think I'd
dice with rush-hour traffic on downhills with it - seems to me it has
teh potential to pirouette and dump you on teh road if you forget
yourself and tug on a brake inappropriately.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

in message <[email hidden]>, Peter Clinch

(') said:

Doki said:

Does anyone make a FWD / rear steer recumbent?

FWD, certainly. Zox and Flevo are the obvious examples, plus the Very
Serious Speed machinery used at the likes of Battle Mountain is
sometimes FWD (well, it's not like they have to go round hairpin
bends...).

Rear steer is a different matter. I think it was in C+ that someone
asked this and Mike Burrows answered it. IIRC he basically said that
what's fine in theory doesn't work quite so well in practice and rear
steer bikes tend to be patronised by people called Koko with large red
noses...

The Flevo is an interesting exception to the usual rules: it doesn't
steer at either wheel but has a hinge in the middle of the bike, and
can be ridden completely no hands as far as steering goes (though bars
are provided to mount brake and gear levers)

Can you post a URL: All I find on the Flevobike site
<URL:http://www.flevobike.nl/indexmodellen.html> is a very nicely
finished and interesting looking velomobile (come to think of it, it's
reviewed in the latest VeloVision). I can't find any reference to your
hinged in the middle bicycle (but being unable to read Dutch is a
drawback here).

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I'd rather live in sybar-space

in message <[email hidden]>, Doki

(') said:

Mark South said:

The problem is that to turn away from an obstacle you have to steer
towards it. This means that situations can arise where it is not
possible to avoid the obstacle with rear steering but it could have
been avoided with front steering.

I'm afraid I don't really *get* countersteering. I must do it, but
I've never noticed myself do it. Probably all bunged away in the brain
stem and never consciously thought about.

Countersteering is one of those things about cycling which people have
religious beliefs about. In practice you can steer a bike by starting
the turn by turning the handlebars the opposite way, in order to get
the wheels out from under the CoG, but it isn't necessary or even
common. If you had a radio controlled bike with a rigidly mounted crash
test dummy this would be the only way to steer it. But 90% of bike
steering at any normal speed is balance and body weight, and
countersteering is very rare in practice (I very rarely do it and
watching other people I very rarely see it.

Mind you, cycling theorists will tell you this is impossible. And that
wheels stand on spokes and that steering is a matter of gyroscopic
precession, and all sorts of other things which are indeed partly true
or true under some circumstances, but which True Believers recite as
mantras of universal truth.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

...but have you *seen* the size of the world wide spider?

Ian Smith said:

On Mon, 21 Jun 2004 15:44:19 +0100, Doki <[email hidden]>

Quoted message said:

Does anyone make a FWD / rear steer recumbent? Seems to me you'd
save a lot of chain length. Perhaps they'd struggle for grip up
hills?

There are FWD,FWS tadpole trikes - russian titanium ones turn up
occasionally.

There's also one that is FWD via a differential, and steered by
braking teh front wheels individually, like a tank. The back wheel is
just a castor. I quite like that as a scheme, but I don't think I'd
dice with rush-hour traffic on downhills with it - seems to me it has
teh potential to pirouette and dump you on teh road if you forget
yourself and tug on a brake inappropriately.

Get a little lug you flip over to lock both brakes together like you do in a
tractor then 😉. Or two sets of brakes on each wheel - one for steering and
one for braking.

In news:[email hidden],
Simon Brooke <[email hidden]> typed:

Quoted message said:

in message <[email hidden]>, Peter Clinch

(') said:

Doki said:

Does anyone make a FWD / rear steer recumbent?

FWD, certainly. Zox and Flevo are the obvious examples, plus the
Very Serious Speed machinery used at the likes of Battle Mountain is
sometimes FWD (well, it's not like they have to go round hairpin
bends...).

The Flevo is an interesting exception to the usual rules: it doesn't
steer at either wheel but has a hinge in the middle of the bike, and
can be ridden completely no hands as far as steering goes (though
bars are provided to mount brake and gear levers)

Can you post a URL: All I find on the Flevobike site
<URL:http://www.flevobike.nl/indexmodellen.html> is a very nicely
finished and interesting looking velomobile (come to think of it, it's
reviewed in the latest VeloVision).

http://home.hccnet.nl/Mark.Maier/recumbents/flevoracer99.jpg

There's one, it's a Flevoracer.

A

Simon Brooke said:

Countersteering is one of those things about cycling which people have
religious beliefs about. In practice you can steer a bike by starting
the turn by turning the handlebars the opposite way, in order to get
the wheels out from under the CoG, but it isn't necessary or even
common. If you had a radio controlled bike with a rigidly mounted crash
test dummy this would be the only way to steer it.

I've got one of them [1], and that is indeed how it steers.

Quoted message said:

But 90% of bike
steering at any normal speed is balance and body weight, and
countersteering is very rare in practice (I very rarely do it and
watching other people I very rarely see it.

I never used to notice it, but now I often notice myself starting a turn
by countersteering. For some reason it's much more noticeable on the
Street Machine that it used to be on my ATB. Perhaps it's more
necessary on a bent than on a wedgie.

[1] It was my 30th birthday present from my Dad. I downloaded a 2.84MB
movie of it in action from <URL:http://www.taiyoedge.com/>, but it
appears to no longer be there. Instead, it should be temporarily
possible to get it from here:
<URL:http://www.speedy5.freeserve.co.uk/z-freestyle.mpg>

--
Danny Colyer (the UK company has been laughed out of my reply address)
<URL:http://www.speedy5.freeserve.co.uk/danny/>
"He who dares not offend cannot be honest." - Thomas Paine

"Simon Brooke" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

in message <[email hidden]>, Doki

(') said:

Mark South said:

The problem is that to turn away from an obstacle you have to steer
towards it. This means that situations can arise where it is not
possible to avoid the obstacle with rear steering but it could have
been avoided with front steering.

I'm afraid I don't really *get* countersteering. I must do it, but
I've never noticed myself do it. Probably all bunged away in the brain
stem and never consciously thought about.

It's not countersteering, with a rear-steer vehicle that is *steering*.

Quoted message said:

Countersteering is one of those things about cycling which people have
religious beliefs about.

But on a rear-steered vehicle you have to swing the rear towards the object you
are trying to avoid. Fact, not religion.

Quoted message said:

In practice you can steer a bike by starting
the turn by turning the handlebars the opposite way, in order to get
the wheels out from under the CoG, but it isn't necessary or even
common. If you had a radio controlled bike with a rigidly mounted crash
test dummy this would be the only way to steer it. But 90% of bike
steering at any normal speed is balance and body weight, and
countersteering is very rare in practice (I very rarely do it and
watching other people I very rarely see it.

Which probably tells you that humans are not well adapted to it as a balance
control mode.

Quoted message said:

Mind you, cycling theorists will tell you this is impossible. And that
wheels stand on spokes and that steering is a matter of gyroscopic
precession, and all sorts of other things which are indeed partly true
or true under some circumstances, but which True Believers recite as
mantras of universal truth.

This is all a bit uncalled-for. There is no myth about what I said relating to
rear-steering recumbents. Nor have I claimed that any of the false statements
above are true.
--
"You need to declare a jihad on your own ignorant ass."
- Ed Dolan in alt.rec.bicycles.recumbent

in message <[email hidden]>, Ambrose Nankivell

(') said:

In news:[email hidden],
Simon Brooke <[email hidden]> typed:

Quoted message said:

in message <[email hidden]>, Peter Clinch

(') said:

Doki wrote:
> Does anyone make a FWD / rear steer recumbent?

FWD, certainly. Zox and Flevo are the obvious examples, plus the
Very Serious Speed machinery used at the likes of Battle Mountain is
sometimes FWD (well, it's not like they have to go round hairpin
bends...).

The Flevo is an interesting exception to the usual rules: it doesn't
steer at either wheel but has a hinge in the middle of the bike, and
can be ridden completely no hands as far as steering goes (though
bars are provided to mount brake and gear levers)

Can you post a URL: All I find on the Flevobike site
<URL:http://www.flevobike.nl/indexmodellen.html> is a very nicely
finished and interesting looking velomobile (come to think of it,
it's reviewed in the latest VeloVision).

http://home.hccnet.nl/Mark.Maier/recumbents/flevoracer99.jpg

There's one, it's a Flevoracer.

Ahh! Interesting.

Questions:

Are the handlebars attached to the forward chassis, or to the rear
chassis?

Are the handlebars rigidly attached, or is there a linkage?

What is the mechanism of the link - does it have bearings like
conventional headset bearings, or something more robust - and are there
mechanical problems at the link in practice?

Has anyone here ridden such a thing and if so how did it ride?

Front wheel drive without twisting the chain line has a lot to be said
for it.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Tony Blair's epitaph, #1: Here lies Tony Blair.
Tony Blair's epitaph, #2: Trust me.

Mark South said:

"You need to declare a jihad on your own ignorant ass."
- Ed Dolan in alt.rec.bicycles.recumbent

Has The Troll of arbr discovered a sense of humour? Maybe I should
rescue him from the killfile....

Mike