Here are two websites I have not seen mentioned recently. The first
http://www.projectvf.com/  looks like it should be the work of an FF
list member and is very interesting.

http://www.diseno-art.com/  is an encyclopaedia of vehicle concepts
and styling exercises. I think most of of the FF designs have been
seen here before, but the site is still worth a look :-)

B.

Hallo all,

after a trip of two hours on my Yamaha Xmax 250 I really started
thinking. Man, my back was nearly broken! I have had this complaint
already a few weeks ater shorter trips, but this time I could no
longer ignore it. I WANT A SEAT WITH A BACK!

Ok, the idea to change my XMAX to a FF with modified seat was my new
brain-spawn. Ok, it has to wait till a few other projects are
finished (a motorized threewheeler (project that might lead into a
productionmodel) and a pushing car for six kids (project for a
kindergarden) ). But ... I want to prepare myself already for this
new task. And if it can be done in a short time I want to to give it
higher priority ... to save my back.

My goal: make a modified seat to house me and my girlfriend. So the
seat may not be too wide at the back.

Questions: why are FF always so low to sit? Are the seats more
forward placed to alter the CG, center of gravity? Would I put my
feetrests more forward for more comfort or are the current feetrests
OK? Does anybody have a good profile-drawing of a manshape in
comfortable position so I can start drawing a modified seat?

Well, that is it for now. Might be that if this project ends good I
might consider a enclosed project with the same engine. I just love
this engine. Powerfull due to fuelinjection, not too much noise
and ...3.5 l/100 km!

Keep that brain spawning wings or wheels (sorry, my usual endphrase),

Koen Van de Kerckhove (Koen for short)
www.nestofdragons.net (weird airplanes)
http://users.skynet.be/nestofdragons/creates (my first recumbent
bikes from the time I couldn't weld at all)  ;^)

________________________________________
From: feet_forward@yahoogroups.com [mailto:feet_forward@yahoogroups.com]
On Behalf Of Koen Van de Kerckhove
Sent: 02 July 2007 12:10
To: feet_forward@yahoogroups.com
Subject: [FF] Possible new project "Nest of Dragons" style

>Hallo all,


>My goal: make a modified seat to house me and my girlfriend. So the
>seat may not be too wide at the back.

>Questions: why are FF always so low to sit?

That is part of what an FF is - you don't have to do the same, but it
won't be an FF. As to why, please refer to
http://www.hightech.clara.net/feetfirs.htm#feet%20first

Also have a read of
http://www.bikeweb.com/node/243


>Are the seats more forward placed to alter the CG, center of gravity?

If I understand you then the answer is - to reach the handlebars!

>Would I put my feetrests more forward for more comfort or are the
current >feetrests OK? Does anybody have a good profile-drawing of a
manshape in
>comfortable position so I can start drawing a modified seat?

All related to the above comment. Once you get your manshape you will
see that once you lower the seat (a good idea) you then have a problem,
either the feet have to go forward, or the handlebars have to come
backwards.

>Well, that is it for now. Might be that if this project ends good I
>might consider a enclosed project with the same engine. I just love
>this engine. Powerfull due to fuelinjection, not too much noise
>and ...3.5 l/100 km!

>Keep that brain spawning wings or wheels (sorry, my usual endphrase),

Have fun!

Peter



______________________________________________________________________
The information contained in this electronic message (e-mail), and any files
transmitted with it, is intended for the named recipient(s) only. It may contain
privileged and/or confidential information and if you are not the intended
recipient, you must not copy, distribute or take any action in reliance on it.
If you have received this electronic message (e-mail), and any files transmitted
with it, in error, please delete it immediately.

Internet communications are not secure and therefore the PM Group does not
accept legal responsibility for the contents of this message. Except where sent
in the ordinary course of business, any views or opinions presented are solely
those of the author and do not necessarily represent those of the PM Group.

The PM Group operates anti-virus programs; nevertheless all attachments with
this message should be checked for viruses before it is opened. The PM Group
cannot be held responsible for failure by the recipient to test for viruses
before opening any attachments and does not accept responsibility for any damage
whatsoever that is caused by viruses being passed.

Should you communicate with anyone at the PM Group by e-mail you consent to us
monitoring and reading any such correspondence. Email is monitored by the PM
Group solely for operational, security and business reasons.
______________________________________________________________________

Koen Van de Kerckhove wrote:
> Questions: why are FF always so low to sit? Are the seats more
> forward placed to alter the CG, center of gravity? Would I put my
> feetrests more forward for more comfort or are the current feetrests
> OK? Does anybody have a good profile-drawing of a manshape in
> comfortable position so I can start drawing a modified seat?

Koen,

Fancy meeting you here, it's a small world.

Funnily enough this link came up on the Atlantica mailing list:
http://www.sciencedaily.com/releases/2006/11/061127112844.htm
which gives a good indication of a reasonable seating position.

I seem to remember downloading a paper on the subject too at the
time, I'll see if I can find it again. Will mail it direct if I
can.

Michael Moore created a virtual dummy called fred which you can
find on his website somewhere. He posted the link a while ago
so you can hunt these forums for it too.

This example might be what you're looking for.
http://www.eurospares.com/graphics/FF/FredRotacularLaidBack.jpg

The ideal seat height is a discussion item, but the concensus,
from the people on here who's opinion I value, is as low as you
can get without scraping your bum on the floor in corners...

Again, there are threads on the subject for the searching.

Welkom en veel geluk,

Graham - Cogito, ergo recubo.

Koen Van de Kerckhove <nestofdragons@...> Mon, 2 Jul 2007
11:10:10
>after a trip of two hours on my Yamaha Xmax 250 I really started
>thinking. Man, my back was nearly broken! I have had this complaint
>already a few weeks ater shorter trips, but this time I could no
>longer ignore it. I WANT A SEAT WITH A BACK!
>
>Ok, the idea to change my XMAX to a FF with modified seat was my new
>brain-spawn. Ok, it has to wait till a few other projects are
>finished (a motorized threewheeler (project that might lead into a
>productionmodel) and a pushing car for six kids (project for a
>kindergarden) ). But ... I want to prepare myself already for this
>new task. And if it can be done in a short time I want to to give it
>higher priority ... to save my back.
>
>My goal: make a modified seat to house me and my girlfriend. So the
>seat may not be too wide at the back.

The minimal solutions are
- Rig up backrests for you and your pillion. Look at Utopia for ideas.
Or see if you can raise the existing bum stop.
- Cut into the foam on the seat to lower yourself a bit
- Tilt the handlebars back and/or fit handlebar brackets that move them
back. Busters, M&P and Demon Tweaks can all supply these.

As someone else said, if you lower the seat, put a backrest on and lean
back a bit, you'll find you need more legroom. This may or may not be a
problem depending on the bike and your shape. On most Megascoots you end
up needing to be monkey shaped (long arms, short legs) or needing to
start hacking bodywork.

See here for some inspiration
http://www.flickr.com/photos/jbond/tags/an400/
http://www.utpr.com/

--
Julian Bond  E&MSN: julian_bond at voidstar.com  M: +44 (0)77 5907 2173
Webmaster:           http://www.ecademy.com/     T: +44 (0)192 0412 433
Personal WebLog:     http://www.voidstar.com/    skype:julian.bond?chat
                      *** Just Say No To DRM ***

Thanks for the quick replies.

Graham, seems like creative persons are always busy with the same
stuff: Working hard on things to make life easy.   ;^)  Happy to see
you here too.

At first I want to save my scooter as much as possible. I don't want
to get problems with the authorities about modifying a scooter and
using it on their roads. Well, not yet getting problems.  :)

I will just try to see myself what the change will be in using this
scooter. If I like it ... which I probably would ... I will try to
convince a few persons to help me with a more advanced design
starting from the engine of the Xmax 250. And Graham, you know ... if
I want to convince, I will convince.   ;^)  (Seems like that big bad
wolf page for the Flying Flea world is still working. Nobody sells
any HM16 plans no more.)

Many thanks for the links towards the more technical papers.

Does anybody know firms that make seats on demand? If possible in the
neighborhood of Belgium. I will try to make a frame of a seat, but it
needs to get covered with some soft stuff to save my butt.

Keep that brain spawning wings or wheels,

Koen

Hallo,

being a scooter-user I had some nasty surprises ont he road. I need to
drive several km on a highway FILLED with trucks. Man, riding on that
highway is really a pain in the ***. I need to make efforts to keep
myself between the lines sometimes. Especially if I ride over a bridge.
Double hard time!
Somebody told me that this is due to the scooter frontpanels. Euh ...
does this mean that a more enclosed scooter will only have even more
problems like that? Or would the lower CG of a FF make the scooter more
stable against those forces of the wind?

I just want to avoid putting myself at a higher risk on those highways.

Keep that brain spawning wings or wheels,

Koen

Julian, thanks for the link to Utopia. Why reinvent the wheel when it
has been done before. But ... it is not mentioned on the site where
they are located. Europe? USA?

I consider very hard to just buy such a backrest there and place a
backtrunk with backrest for my girlfriend at the back. Might already do
the trick. But ... my head already is thinking about the more advanced
design. Hihi, too much free time as a teacher to stay without projects
going on.

Keep that brain spawning wings,

Koen

PS. the only fear I have is that the backrest is too wide. I have
access to smaller backrests in carbon which are normally used in
recumbent bikes. Might be that I alter such a seat and havev it covered
with foam and leather.

>
> See here for some inspiration
> http://www.flickr.com/photos/jbond/tags/an400/
> http://www.utpr.com/
>
> --
> Julian Bond

Koen Van de Kerckhove <nestofdragons@...> Mon, 2 Jul 2007
13:09:57
>Julian, thanks for the link to Utopia. Why reinvent the wheel when it
>has been done before. But ... it is not mentioned on the site where
>they are located. Europe? USA?

USA. But the Dollar-Euro rate means they're a reasonable price. But they
probably don't make anything for the XMax. But it was really for
inspiration. There's not a whole lot to them so perhaps you could bodge
something together kind of like it.

>I consider very hard to just buy such a backrest there and place a
>backtrunk with backrest for my girlfriend at the back. Might already do
>the trick.

Don't let the longer term pipe dreams stop you from doing a little now.
;)

--
Julian Bond  E&MSN: julian_bond at voidstar.com  M: +44 (0)77 5907 2173
Webmaster:           http://www.ecademy.com/     T: +44 (0)192 0412 433
Personal WebLog:     http://www.voidstar.com/    skype:julian.bond?chat
                      *** Just Say No To DRM ***

Koen Van de Kerckhove wrote:
>Hallo all,
>
>after a trip of two hours on my Yamaha Xmax 250 I really started
>thinking. Man, my back was nearly broken! I have had this complaint
>already a few weeks ater shorter trips, but this time I could no
>longer ignore it. I WANT A SEAT WITH A BACK!

Hello (from CabinScooters too)

I can see that the X-max has a very upright seating position:
<http://www.yamaha-motor-europe.com/Images/2007_X-MAX250_Photo_01_tcm26-141969.j\
pg>

Here is a 'manshape' drawn on a side view of an X-max:
<http://i86.photobucket.com/albums/k115/angibb/X-max-FF.jpg>

If you add a rider's backrest, I can see that it will stop you from slouching -
sinking down so that your back is curved.  But because you sit so upright, you
will never lean against a backrest much - like for example at shoulder level -
unless you change the seating position and that starts to be a big change.

To change the seating position on the bigger T-max didn't take a lot of work -
only bodywork changes, no frame changes - so you might be lucky and find the
X-max is as easy to change.  The problem is that you will quickly get to the
point where the change you want to make is not reversible - and making it so you
cannot change the X-max back to standard and sell it is a big step.

It looks like you should start with a backrest like the Utopia and if you don't
like it you can buy a new seat to go back to standard - but you might want to
find out how much a new X-max seat is, as the T-max on is not cheap.

Andrew

As some have already found out, I have written up the Italian job on Bikeweb.
<Feet Forward to?Florence>?There are a small number of photos there too.

I hope it will provide a minor diversion from whatever you were doing.
?
Graham (V05 in the blue period)
________________________________________________________________________
Get a FREE AOL Email account with 2GB of storage.  Plus, share and store photos
and experience exclusively recorded live music Sessions from your favourite
artists. Find out more at http://info.aol.co.uk/joinnow/?ncid=548.


[Non-text portions of this message have been removed]

http://www.eurospares.com/graphics/fred_ergo/

Koen, that's the folder on my website that houses the various
images of Fred, as well as Rhino and DXF drawings.

Fred is actually Tony Foale's pal.  I just brought him into the digital
world.

cheers,
Michael

Hi, Guys, from the sub-Group 'FF Lurkers'.

Popped into the Anglesey Circuit - (secondary name Ty Croes) a week
ago, for the first time in a couple of years and was pleasantly
stunned by the new track, that had been rumoured, but I'd no idea it
had happened.

It's completely new, covers a much bigger area, at 2.10 miles is twice
as long as the old track. I can only identify as still in use, just
one small part of the old track that I rode a few years back. The new
one sweeps up and down and around the undulating landscape bordered by
the cliff-tops. It's got a variety of corners, notably a sweeping
straight along the cliff-top (not too near!) that starts like
Clearways and isn't quite straight, thus making it like some of
Cadwell's 'straights' and Thruxton. Fast and slow corners and medium
speed corners and one right-hander - Peel - named after John, I read -
with a curving exit over a crest that goes downhill to a left-hander.
What's still the same are the beautiful sea views over the 'Rivals'
and the Lleyn peninsula.

Spectator views are great, lots of banking and one plateau that
commands a view over most of the circuit.

If going to a Track day, you'd better check what circuit their using,
the best is the International one (obviously) but the others could be
OK, the Coastal one for sure.

http://www.angleseycircuit.com/circuits.html
  
http://www.visordown.com/motorcyclenews/view/exclusive_aerial_shot_of_new_angles\
ey_circuit/348.html

Salaam Aliekum, Eddie McD

Posted by: "Koen Van de Kerckhove" nestofdragons@...  said:

At first I want to save my scooter as much as possible. I don't want
to get problems with the authorities about modifying a scooter and
using it on their roads. Well, not yet getting problems. :)

Hi Koen, (I presume that , as a Vlaams, your name rhymes with "soon"
in Engels, not "fern")
I'm inclined to say that, before you do anything to your XMax, you
should try to get a ride in Monty Billington's ComforTmax (which was
initially converted by Royce Creasey like this:
http://www.bikeweb.com/node/474
and this:
http://www.bikeweb.com/node/713

and finished off over a three year period by Andrew Gibbens, like this:
http://www.bikeweb.com/node/871
and this:
http://www.bikeweb.com/node/851

Monty is only a hop, skip and jump across the Nord Zee in darkest
Yorkshire. Hopefully you will then realise that you'd be far better
advised to sell or trade in your Xmax against a good condition
Tmax500. It has far more leg room to start with, not to mention about
twice the power.
(OK, it uses more fuel too, but you only live once and it will be
twice the fun!)

You should also look at Colin Ferguson's ComFergMax here:
http://www.bikeweb.com/node/1102
here:
http://www.bikeweb.com/node/1139
and here:
http://www.bikeweb.com/node/1108

Koen also said:
   "I need to make efforts to keep myself between the lines sometimes.
Especially if I ride over a bridge.
Double hard time! Somebody told me that this is due to the scooter
frontpanels. Euh ... "

PNB: This is bollocks (nonsense) IMHO

K: does this mean that a more enclosed scooter will only have even more
problems like that?

PNB: Not necessarily. Not if you keep the centre of pressure behind
the centre of gravity.

See here for an example of a stable two wheeler with a lot of bodywork!:
http://www.peraves.ch/
PNB

I

Looks like September is too busy with other events such as Quasar meet so
may have to delay it until October.


BBC2's Top Gear program April 1988, The FEET FORWARD special NOW AVAILABLE
on CD-ROM, contact me for details PLUS FF open day at my house
4 CD set includes all my collection of FF Photos
http://www.Monty-FF.me.uk

Best regards
Monty AKA Peter Billington
Mobile +44 (0) 7903 6464 95
Monty.FF@...

-----Original Message-----
From: Arthur Middleton home [mailto:artmidd@...]
Sent: 02 July 2007 21:58
To: Monty.FF@...
Subject: RE: Quasar meet

Hi Monty,

Any more plans for an FF meeting this year? Also I can't find the email you
sent re your possible Irish trip. When were you planning this again?

Arthur.

>-----Original Message-----
>From: Monty AKA Peter Billington [mailto:Monty.FF@...]
>Sent: 02 July 2007 20:28
>To: 'Mark Crowson'; 'Arthur Middleton home'
>Subject: RE: Quasar meet
>
>
>Count me in, hopefully in dat Carver thing.
>
>
>BBC2's Top Gear program April 1988, The FEET FORWARD special NOW
>AVAILABLE on CD-ROM, contact me for details PLUS FF open day at my
>house
>4 CD set includes all my collection of FF Photos
>http://www.Monty-FF.me.uk
>
>Best regards
>Monty AKA Peter Billington
>Mobile +44 (0) 7903 6464 95
>Monty.FF@...
>
>-----Original Message-----
>From: Mark Crowson [mailto:mark@...]
>Sent: 02 July 2007 20:10
>To: Arthur Middleton home
>Cc: Monty Billington
>Subject: Re: Quasar meet
>
>Hi Arthur,
>I'm expecting a modest get-together, probably on the first week-end in
>September (ie 1st 2nd), just a chance to go out and play together.
>I'm planning a trip out on Sunday along the coast to 'Howletts' at
>Hythe, which is one of John Aspinal's places.  See the gorillas,
>rhinos, elephants, lions & tigers and all that stuff.
>I'd be very pleased if you were able to join us.
>
>Mark
>
>----- Original Message -----
>From: "Arthur Middleton home" <artmidd@...>
>To: "Mark Crowson" <mark@...>
>Sent: Monday, July 02, 2007 2:03 PM
>Subject: Quasar meet
>
>
>> Hi Mark,
>>
>> Is a Quasar meeting planned for September this year? I might come
>> along if
>it is. You
>> might inform Monty, maybe via the FF list, if you are planning one as
>> he
>is, I think,
>> planning an FF meeting in Yorkshire sometime. It would be too bad if
>> the
>few FF events of
>> the year were to clash.
>>
>> Arthur.
>>
>>
>>
>> --
>> This email has been verified as Virus free Virus Protection and more
>> available at http://www.plus.net
>
>
>
>

The more aerodynamic your machine is, the more it is affected by air
conditions. Naturally enough, as a machine with rubbish aerodynamics just
batters through anything.

The best solution is to use your mind to visualise the wind.

If you ever go out on water in a small boat with an outboard engine, you
learn how to handle it in order to cross the wake of larger, faster boats.
The wake forms a permanent wave leading backwards in a V shape from the
larger boat (and sometimes two waves, one from the bow one from the stern).
As you approach the wake you turn into it briefly to cross it - otherwise
the wave will slap the side of your boat and rock you more than you want.

(The same applies if you are offroading and you want to cross a rut that
runs in the direction of your travel: you don't ride down it as it will trap
the steering and have you off, you steer firmly across it. A rut is like a
wave in mud.)

Although mud is more relevant to bikes I find the analogy of crossing wakes
in a boat to be more useful on the road.

Big trucks have two V-shaped pressure waves, one at the front coming off the
cab, and another at the rear. In fact the pattern of turbulence at the rear
is interesting, there is a very rough area about a truck length behind where
the two wakes from each back corner cross, but there is also a triangle of
quiet air directly behind the truck where you can sit and use less fuel at
speed.

If you are crossing a bridge with a crosswind and there are trucks on it, by
visualising the wind pattern you can steer to compensate. The crosswind
disappears (of course) when you are level with the truck and reappears as
you go past it. All this is bleedin' obvious but if you don't work it out
but just hang on to the handlebars each change in pressure comes as a
surprise and you end up flapping all over the place.

You counter crosswinds as you probably know by countersteering. That is, in
order to go straight you push the handlebars in the wrong direction, that is
not into the wind but away from it, apparently towards the ditch that the
wind is pushing you into. This unbalances the machine and causes it to
'fall' in the direction of the wind, but by magic you end up tracking
straight while the machine is well off vertical.

As a footnote us open machine riders have a sense of the wind because you
can feel it on your head and shoulders. Ecomobile pilots in their air
conditioned cocoons feel no wind at all. I suppose the only knowledge an eco
pilot will have of a crosswind would be visual, as in 'hey I'm not going
straight' followed by a little countersteering pressure on the handlebars to
correct the direction of travel. In a heavy crosswind is the only time that
the G forces in an eco cabin are anything other than vertical.

_________________________________________________________________
http://liveearth.msn.com

On 7/2/07, Andy Tribble <tribbikes@...> wrote:
>
>   The more aerodynamic your machine is, the more it is affected by air
> conditions. Naturally enough, as a machine with rubbish aerodynamics just
> batters through anything.
>
> The best solution is to use your mind to visualise the wind.
>
> If you ever go out on water in a small boat with an outboard engine, you
> learn how to handle it in order to cross the wake of larger, faster boats.
>
> The wake forms a permanent wave leading backwards in a V shape from the
> larger boat (and sometimes two waves, one from the bow one from the
> stern).
> As you approach the wake you turn into it briefly to cross it - otherwise
> the wave will slap the side of your boat and rock you more than you want.
>
> (The same applies if you are offroading and you want to cross a rut that
> runs in the direction of your travel: you don't ride down it as it will
> trap
> the steering and have you off, you steer firmly across it. A rut is like a
>
> wave in mud.)
>
> Although mud is more relevant to bikes I find the analogy of crossing
> wakes
> in a boat to be more useful on the road.
>
> Big trucks have two V-shaped pressure waves, one at the front coming off
> the
> cab, and another at the rear. In fact the pattern of turbulence at the
> rear
> is interesting, there is a very rough area about a truck length behind
> where
> the two wakes from each back corner cross, but there is also a triangle of
>
> quiet air directly behind the truck where you can sit and use less fuel at
>
> speed.
>
> If you are crossing a bridge with a crosswind and there are trucks on it,
> by
> visualising the wind pattern you can steer to compensate. The crosswind
> disappears (of course) when you are level with the truck and reappears as
> you go past it. All this is bleedin' obvious but if you don't work it out
> but just hang on to the handlebars each change in pressure comes as a
> surprise and you end up flapping all over the place.
>
> You counter crosswinds as you probably know by countersteering. That is,
> in
> order to go straight you push the handlebars in the wrong direction, that
> is
> not into the wind but away from it, apparently towards the ditch that the
> wind is pushing you into. This unbalances the machine and causes it to
> 'fall' in the direction of the wind, but by magic you end up tracking
> straight while the machine is well off vertical.
>
> As a footnote us open machine riders have a sense of the wind because you
> can feel it on your head and shoulders. Ecomobile pilots in their air
> conditioned cocoons feel no wind at all. I suppose the only knowledge an
> eco
> pilot will have of a crosswind would be visual, as in 'hey I'm not going
> straight' followed by a little countersteering pressure on the handlebars
> to
> correct the direction of travel. In a heavy crosswind is the only time
> that
> the G forces in an eco cabin are anything other than vertical.
>

Well done lesson Andy!

The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
to steer itself toward the wind (which sets the bike up nicely for fighting
the effects of the cross wind).

Dan Whitfield



    __________________________________________________________
> http://liveearth.msn.com
>
>
>


[Non-text portions of this message have been removed]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?
ViewItem&item=330142445438&fromMakeTrack=true&ssPageName=VIP:watchlink:
middle:uk

>
>http://cgi.ebay.co.uk/ws/eBayISAPI.dll?
>ViewItem&item=330142445438&fromMakeTrack=true&ssPageName=VIP:watchlink:
>middle:uk

With long links like this it is easier to paste them in sections into
http://tinyurl.com/
first, especially when the link wraps into more than 2 lines as it did on my
email.

Arthur.

The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
to steer itself toward the wind (which sets the bike up nicely for fighting
the effects of the cross wind).
Not wierd, but classic C of P behind C of G. Why tail fairings are important etc
etc.

Graham

________________________________________________________________________
Get a FREE AOL Email account with 2GB of storage.  Plus, share and store photos
and experience exclusively recorded live music Sessions from your favourite
artists. Find out more at http://info.aol.co.uk/joinnow/?ncid=548.


[Non-text portions of this message have been removed]

Grahamrobb@... wrote:

>The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
>to steer itself toward the wind (which sets the bike up nicely for fighting
>the effects of the cross wind).
>Not wierd, but classic C of P behind C of G. Why tail fairings are important
etc etc.

Yes, but explain to me how that can be.  The relatively heavy BMW engine is near
the back and the Eco has a plan view shape very much like a truncated aerofoil
which would lead you to expect the CoP to be well forward of mid length and that
it could generate a lot of 'lift'.  Something does not compute here....

Please note I'm not saying it ain't true - clearly enough people have found the
Eco to be stable - I'm just questioning how it is true.

Is the Eco an example of the theory someone once proposed here (based I think on
some pedal cycle experiments) that CoP forward of CoG causes sidewinds to induce
countersteer away from the wind, which causes roll into the wind, which gives
stability.  I think there are several holes in this theory large enough for at
least one horse, if not a whole cart.  But that doesn't mean it's untrue,
either!

Andrew

Dan Whitfield wrote:

>The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
>to steer itself toward the wind (which sets the bike up nicely for fighting
>the effects of the cross wind).

Dan,

As a measure of how much side force the Eco generates (which is quite different
from whether it is stable), how far over does it lean in strong cross winds?  As
far as a 'serious cornering' angle?  Or just a 'slight tilt'? Somewhere in
between?

The amount of lean tells us how much side force it generates, although I'm not
sure it's comparable to conventional bikes - the FF may have a CoG that's even
lower than its bodywork might suggest. Or to put it another way, the FF may well
have more bodywork high up (relative to its CoG) than a HF, so would have to
lean further to achieve roll balance.

Andrew

Arthur Middleton home wrote:

>With long links like this it is easier to paste them in sections into
http://tinyurl.com/
>first, especially when the link wraps into more than 2 lines as it did on my
email.

Or just enclose them in carets for most email programs:
<http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=330142445438&fromMakeTrack\
=true&ssPageName=VIP:watchlink:middle:uk>

That's a test to demonstrate it works.

Andrew

Andrew Gibbens wrote:
> Dan Whitfield wrote:
>
>> The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
>> to steer itself toward the wind (which sets the bike up nicely for fighting
>> the effects of the cross wind).
>
> Dan,
>
> As a measure of how much side force the Eco generates (which is quite
different from whether it is stable), how far over does it lean in strong cross
winds?  As far as a 'serious cornering' angle?  Or just a 'slight tilt'?
Somewhere in between?
>
> The amount of lean tells us how much side force it generates, although I'm not
sure it's comparable to conventional bikes - the FF may have a CoG that's even
lower than its bodywork might suggest. Or to put it another way, the FF may well
have more bodywork high up (relative to its CoG) than a HF, so would have to
lean further to achieve roll balance.
>
> Andrew

Andrew,

I'm sure we've gone over this before... (Ian, come back, all is
forgiven...) Tony has a picture in his book which shows how much more
than a standard BMW the eco rolls due to a cross wind.

It seems to me that the stability of the eco along with the concentrated
mass along it's centre line allows it to quickly acheive a new stable state.

So it's not a case that it's less affected by winds, rather it is more
affected but acheives a new stable state before the rider has a chance
to respond and aggravate the effect.

Of course I could be completely wrong...

Graham - Cogito, ergo recubo.

>Grahamrobb@... wrote:
>
>>The weird part of the ECOMOBILE ride is that an unseen wind causes the ECO
>>to steer itself toward the wind (which sets the bike up nicely for fighting
>>the effects of the cross wind).
>>Not wierd, but classic C of P behind C of G. Why tail fairings are important
etc etc.
>
>Yes, but explain to me how that can be.  The relatively heavy BMW engine is
near
>the back and the Eco has a plan view shape very much like a truncated aerofoil
>which would lead you to expect the CoP to be well forward of mid length and
that
>it could generate a lot of 'lift'.  Something does not compute here....
>
>Please note I'm not saying it ain't true - clearly enough people have found the
>Eco to be stable - I'm just questioning how it is true.
>
>Is the Eco an example of the theory someone once proposed here (based I think
on
>some pedal cycle experiments) that CoP forward of CoG causes sidewinds to
induce
>countersteer away from the wind, which causes roll into the wind, which gives
>stability.  I think there are several holes in this theory large enough for at
>least one horse, if not a whole cart.  But that doesn't mean it's untrue,
either!
>
>Andrew

I think we have to consider more than one effect. The CP is above the ground
plane so the
side wind leans the bike away from the wind. This will induce a steer (via the
tail) to
the lee side which counter steers the lean back to windward, as long as the
rider doesn't
interfere. Now if we have a strong forward component, like a Windjammer fairing
and no
tail, we also have a rotation about a vertical axis to counteract.

The inertia of the bike means the vertical axis rotation is slower than the
tilt, but if
the force is big enough seems to make the bike unstable.

Happily, whatever the cause, the VFFF is stable as long as I have a light grip
on the
bars, or ride hands off.

I think we can easily extrapolate well beyond validity when using HPV data for
FFs.

Arthur.

Top post on purpose as I'm not commenting on the contents of the post...

Andy,

Would it be worth putting this on bikeweb, I'll read it when I get a bit
more time, but at first glance it's a good summary.

Graham - Cogito, ergo recubo.

Andy Tribble wrote:
> The more aerodynamic your machine is, the more it is affected by air
> conditions. Naturally enough, as a machine with rubbish aerodynamics just
> batters through anything.
>
> The best solution is to use your mind to visualise the wind.
>
> If you ever go out on water in a small boat with an outboard engine, you
> learn how to handle it in order to cross the wake of larger, faster boats.
> The wake forms a permanent wave leading backwards in a V shape from the
> larger boat (and sometimes two waves, one from the bow one from the stern).
> As you approach the wake you turn into it briefly to cross it - otherwise
> the wave will slap the side of your boat and rock you more than you want.
>
> (The same applies if you are offroading and you want to cross a rut that
> runs in the direction of your travel: you don't ride down it as it will trap
> the steering and have you off, you steer firmly across it. A rut is like a
> wave in mud.)
>
> Although mud is more relevant to bikes I find the analogy of crossing wakes
> in a boat to be more useful on the road.
>
> Big trucks have two V-shaped pressure waves, one at the front coming off the
> cab, and another at the rear. In fact the pattern of turbulence at the rear
> is interesting, there is a very rough area about a truck length behind where
> the two wakes from each back corner cross, but there is also a triangle of
> quiet air directly behind the truck where you can sit and use less fuel at
> speed.
>
> If you are crossing a bridge with a crosswind and there are trucks on it, by
> visualising the wind pattern you can steer to compensate. The crosswind
> disappears (of course) when you are level with the truck and reappears as
> you go past it. All this is bleedin' obvious but if you don't work it out
> but just hang on to the handlebars each change in pressure comes as a
> surprise and you end up flapping all over the place.
>
> You counter crosswinds as you probably know by countersteering. That is, in
> order to go straight you push the handlebars in the wrong direction, that is
> not into the wind but away from it, apparently towards the ditch that the
> wind is pushing you into. This unbalances the machine and causes it to
> 'fall' in the direction of the wind, but by magic you end up tracking
> straight while the machine is well off vertical.
>
> As a footnote us open machine riders have a sense of the wind because you
> can feel it on your head and shoulders. Ecomobile pilots in their air
> conditioned cocoons feel no wind at all. I suppose the only knowledge an eco
> pilot will have of a crosswind would be visual, as in 'hey I'm not going
> straight' followed by a little countersteering pressure on the handlebars to
> correct the direction of travel. In a heavy crosswind is the only time that
> the G forces in an eco cabin are anything other than vertical.
>
> _________________________________________________________________
> http://liveearth.msn.com

snip
>Big trucks have two V-shaped pressure waves, one at the front coming off the
>cab, and another at the rear. In fact the pattern of turbulence at the rear
>is interesting, there is a very rough area about a truck length behind where
>the two wakes from each back corner cross, but there is also a triangle of
>quiet air directly behind the truck where you can sit and use less fuel at
>speed.

And hope the truck doesn't stop in a hurry...

>As a footnote us open machine riders have a sense of the wind because you
>can feel it on your head and shoulders. Ecomobile pilots in their air
>conditioned cocoons feel no wind at all. I suppose the only knowledge an eco
>pilot will have of a crosswind would be visual, as in 'hey I'm not going
>straight' followed by a little countersteering pressure on the handlebars to
>correct the direction of travel. In a heavy crosswind is the only time that
>the G forces in an eco cabin are anything other than vertical.

It seems that the Eco has balanced the side area so it is self correcting. I
found a large
front fairing and no tail made one of my upright bikes unstable in cross winds.

A question for Dan. In a strong gusting cross wind at low speed, does the Eco
react worse
when you hold the bars firmly?

As we know, the faster the bike speed, the less effect the cross wind has. Its
resultant
incident angle reduces to closer to head on and we have more gyroscopic inertia.
I believe
this speed effect is why the HPV (and probably much of the economy run because
low speeds
are a way to save fuel) experience is less relevant than might appear at first
glance.

Arthur.

>Arthur Middleton home wrote:
>
>>With long links like this it is easier to paste them in sections into
>http://tinyurl.com/
>>first, especially when the link wraps into more than 2 lines as it did on my
email.
>
>Or just enclose them in carets for most email programs:
><http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=330142445438&fromMakeTrac\
k=
>true&ssPageName=VIP:watchlink:middle:uk>
>
>That's a test to demonstrate it works.
>
>Andrew

I think it only works if you send it that way. Doesn't work if it is already
broken up by
wrapping. See what happened above? I'm using Outlook and it arrived OK but is
sending
wrapped.

Arthur.

Andrew said:

<<expect the CoP to be well forward of mid length and that it could generate a
lot of 'lift'. Something does not compute here....>>>

Agreed - it seems that I was oversimplifying things. (no change there)

Although it would be interesting to learn of the weight distribution of an
occupied Eco. The driver is?well forward so that would counter the rearward bias
of the engine.
Graham




________________________________________________________________________
Get a FREE AOL Email account with 2GB of storage.  Plus, share and store photos
and experience exclusively recorded live music Sessions from your favourite
artists. Find out more at http://info.aol.co.uk/joinnow/?ncid=548.


[Non-text portions of this message have been removed]

Graham Addis wrote:

>So it's not a case that it's less affected by winds, rather it is more
>affected but acheives a new stable state before the rider has a chance
>to respond and aggravate the effect.

Which is what the Quasar did in spades - ultra-stable, or more precisely
auto-stable in that it required no rider input to be stable. But two problems:
1) Open sides and not much thigh/bum/back location, so the fear that the bike
would run straight while you were blown out the side of it meant it was very
hard not to grip the bars tightly!
2) Side area high up but low CoG, so it had to roll a long way to get roll
balance - which it did, all on its own and bloody fast too.  In submarines there
is a (quite different) phenomenon called 'snap roll' and that's a good phrase to
describe the Quasar's response.  Like being blown out the side, there was a
reasonable fear that the bike would roll to its equilibrium angle but that the
rider would be left behind sitting upright!

Paul will tell us that these are insignificant problems, but then Paul has a
defective fear chip....

Andrew