Funky crankset

email hidden said:

Hi All,

Here is an interesting item:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

I wonder what the theory is behind the design.

Joseph

I reckon these cranks are from back in the 80s when i lot of new
cranks, chainwheels etc came out trying to improve on pedalling
efficiencies

Steve

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

Quoted message said:

Hi All,

Here is an interesting item:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

I wonder what the theory is behind the design.

They almost look like some sort of promotional gimmick for connecting rods.

Dans le message de news:[email hidden],
Carl Sundquist <[email hidden]> a réfléchi, et puis a déclaré :

Quoted message said:

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

Quoted message said:

Hi All,

Here is an interesting item:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

I wonder what the theory is behind the design.

They almost look like some sort of promotional gimmick for connecting
rods.

First impression was manacles and bondage, but I have a headache, and today
is not going well.
--
Sandy
--
C'est le contraire du vélo, la bicyclette.
Une silhouette profilée mauve fluo dévale
à soixante-dix à l'heure : c'est du vélo.
Deux lycéennes côte à côte traversent
un pont à Bruges : c'est de la bicyclette.
-Delerm, P.

Quoted message said:

Here is an interesting item:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898
I wonder what the theory is behind the design.

Adjustable crank length used in a sizing/fitting system

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

On Sat, 19 May 2007 12:14:30 -0500, A Muzi <[email hidden]>

Quoted message said:

Quoted message said:

Here is an interesting item:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898
I wonder what the theory is behind the design.

Adjustable crank length used in a sizing/fitting system

Seems unlikely, there are easier ways to make an adjustable length
crank.

I'm thinking maybe a system which puts the pedal spindle (rotational
axis) somewhat above the sole of your foot - a sort of negative stack
height.

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

email hidden said:

Hi All,

Here is an interesting item:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

I wonder what the theory is behind the design.

Joseph

Dear Joseph,

It's a modern version (like the Shimano AX) of the Ramsey Swinging
Pedal of 1898, pictured below:

http://i12.tinypic.com/5z2l4ph.jpg

Here's the theory, which is entertaining balderdash:

"Ramsey’s Swinging Pedal is one of the decided novelties for 1898,
designed primarily to add to the ease of controlling a bicycle through
its driving mechanism, to render it less difficult than formerly to
catch a slipped pedal, and to allow the freest ankle motion. In
action, it transmits automatically, in conformity with the arc of the
circle described by the pedals, the applied power of the rider, thus
maintaining the full leverage of the crank over an increased arc of
that circle, converting the straight push into an improved and
automatic ankle motion. It is claimed to entirely obviate the 'dead
center,' thus avoiding the hammer blow and back lash of the chain,
developing more propelling power than can be obtained by the best
ankle motion with the ordinary pedals. The pick-up of a Ramsey pedal
is instantaneous, and momentum is gained at once; the pedal is always
right side up, and consequently the toe-clip is always ready for the
foot. With so little depth of pedal beneath the foot, the rider is
enabled to sit nearer the ground without decreasing the distance
between the ground and the pedal. Manufactured by the Ramsey Swinging
Pedal Company, Philadelphia, Pa."

Price, $5.00.

"Outing" magazine, p. 104-5

http://www.aafla.org/SportsLibrary/Outing/Volume_32/outXXXII01/outXXXII01ze.pdf

Cheers,

Carl Fogel

Quoted message said:

email hidden said:

Hi All,

Here is an interesting item:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

I wonder what the theory is behind the design.

Joseph

Dear Joseph,

It's a modern version (like the Shimano AX) of the Ramsey Swinging
Pedal of 1898, pictured below:

http://i12.tinypic.com/5z2l4ph.jpg

Here's the theory, which is entertaining balderdash:

"Ramsey’s Swinging Pedal is one of the decided novelties for 1898,
designed primarily to add to the ease of controlling a bicycle through
its driving mechanism, to render it less difficult than formerly to
catch a slipped pedal, and to allow the freest ankle motion. In
action, it transmits automatically, in conformity with the arc of the
circle described by the pedals, the applied power of the rider, thus
maintaining the full leverage of the crank over an increased arc of
that circle, converting the straight push into an improved and
automatic ankle motion. It is claimed to entirely obviate the 'dead
center,' thus avoiding the hammer blow and back lash of the chain,
developing more propelling power than can be obtained by the best
ankle motion with the ordinary pedals. The pick-up of a Ramsey pedal
is instantaneous, and momentum is gained at once; the pedal is always
right side up, and consequently the toe-clip is always ready for the
foot. With so little depth of pedal beneath the foot, the rider is
enabled to sit nearer the ground without decreasing the distance
between the ground and the pedal. Manufactured by the Ramsey Swinging
Pedal Company, Philadelphia, Pa."

Price, $5.00.

"Outing" magazine, p. 104-5

http://www.aafla.org/SportsLibrary/Outing/Volume_32/outXXXII01/outXXXII01ze.pdf

Cheers,

Carl Fogel

Here's a picture of an actual 1898 Ramsey Swinging Pedal:

http://www.speedplay.com/pedalmuseum/images/1898_ramsey_swinging.jpg

"The tread was offset below the axis for 'automatic ankle action, no
dead center . . . money refunded if Ramsey pedals do not enable you to
ascend hills with 25% less energy'."

Presumably the design was secretly banned by the UCI, since a 25%
power advantage from pedals would have bankrupted the drug companies.

You can see it with other pedals by browsing left and right on this
pedal history timeline:

http://www.speedplay.com/index.cfm?fuseaction=pedalmuseum.quill

CF

<[email hidden]> wrote: I wonder what the theory is behind
the design.
^^^^^^^^^^^^^^^^

This is how I have combined reverse engineering and guesswork:

The pedals are attached to small gears, which revolve inside ring gears, so
they stay horizontal all the time. As the cranks rotate, then, their
effective length changes from a minimum to a maximum and back again. This
is equivalent to shifting the gearing up and down with each pedal stroke.
You can accomplish the same thing with an elliptical chainring more simply
and with less weight. I like elliptical chainrings on my mountain
bike--Jobst says they are worthless. We would probably have the same
diagreement about these gadgets, but the weight and dollar penalty would be
higher.

Quoted message said:

On 19 May 2007 04:21:20 -0700, "[email hidden]"

Quoted message said:

Hi All,

Quoted message said:

Here is an interesting item:

Quoted message said:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

I wonder what the theory is behind the design.

Quoted message said:

Joseph

Dear Joseph,

It's a modern version (like the Shimano AX) of the Ramsey Swinging
Pedal of 1898, pictured below:

http://i12.tinypic.com/5z2l4ph.jpg

Here's the theory, which is entertaining balderdash:

"Ramsey's Swinging Pedal is one of the decided novelties for 1898,
designed primarily to add to the ease of controlling a bicycle through
its driving mechanism, to render it less difficult than formerly to
catch a slipped pedal, and to allow the freest ankle motion. In
action, it transmits automatically, in conformity with the arc of the
circle described by the pedals, the applied power of the rider, thus
maintaining the full leverage of the crank over an increased arc of
that circle, converting the straight push into an improved and
automatic ankle motion. It is claimed to entirely obviate the 'dead
center,' thus avoiding the hammer blow and back lash of the chain,
developing more propelling power than can be obtained by the best
ankle motion with the ordinary pedals. The pick-up of a Ramsey pedal
is instantaneous, and momentum is gained at once; the pedal is always
right side up, and consequently the toe-clip is always ready for the
foot. With so little depth of pedal beneath the foot, the rider is
enabled to sit nearer the ground without decreasing the distance
between the ground and the pedal. Manufactured by the Ramsey Swinging
Pedal Company, Philadelphia, Pa."

Price, $5.00.

"Outing" magazine, p. 104-5

http://www.aafla.org/SportsLibrary/Outing/Volume_32/outXXXII01/outXXX...

Cheers,

Carl Fogel

That's some impressive mumbo-jumbo! Have you ever played buzz-word
bingo?

The funny thing about these pedals is they seem to be fixed to the
black rings at the forward position, and presumably the black rings
are free to rotate. At first I thought this would be a wobbly set-up
like a huge stack height, but as the pedal is fixed at the forward
position, perhaps it is in a way "self-energizing" in a way that
changes the crank length during the power stroke. I wonder if it tends
to push the pedal one way or the other in some uncomfortable way. I
might just have to find out!

Joseph

email hidden said:

Quoted message said:

On 19 May 2007 04:21:20 -0700, "[email hidden]"

Quoted message said:

Hi All,

Quoted message said:

Here is an interesting item:

Quoted message said:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

I wonder what the theory is behind the design.

Quoted message said:

Joseph

Dear Joseph,

It's a modern version (like the Shimano AX) of the Ramsey Swinging
Pedal of 1898, pictured below:

http://i12.tinypic.com/5z2l4ph.jpg

Here's the theory, which is entertaining balderdash:

"Ramsey's Swinging Pedal is one of the decided novelties for 1898,
designed primarily to add to the ease of controlling a bicycle through
its driving mechanism, to render it less difficult than formerly to
catch a slipped pedal, and to allow the freest ankle motion. In
action, it transmits automatically, in conformity with the arc of the
circle described by the pedals, the applied power of the rider, thus
maintaining the full leverage of the crank over an increased arc of
that circle, converting the straight push into an improved and
automatic ankle motion. It is claimed to entirely obviate the 'dead
center,' thus avoiding the hammer blow and back lash of the chain,
developing more propelling power than can be obtained by the best
ankle motion with the ordinary pedals. The pick-up of a Ramsey pedal
is instantaneous, and momentum is gained at once; the pedal is always
right side up, and consequently the toe-clip is always ready for the
foot. With so little depth of pedal beneath the foot, the rider is
enabled to sit nearer the ground without decreasing the distance
between the ground and the pedal. Manufactured by the Ramsey Swinging
Pedal Company, Philadelphia, Pa."

Price, $5.00.

"Outing" magazine, p. 104-5

http://www.aafla.org/SportsLibrary/Outing/Volume_32/outXXXII01/outXXX...

Cheers,

Carl Fogel

That's some impressive mumbo-jumbo! Have you ever played buzz-word
bingo?

The funny thing about these pedals is they seem to be fixed to the
black rings at the forward position, and presumably the black rings
are free to rotate. At first I thought this would be a wobbly set-up
like a huge stack height, but as the pedal is fixed at the forward
position, perhaps it is in a way "self-energizing" in a way that
changes the crank length during the power stroke. I wonder if it tends
to push the pedal one way or the other in some uncomfortable way. I
might just have to find out!

Joseph

Dear Joseph,

No, they're not fixed. You can see them rotating in the different
pictures in the ad:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Look at the crank with no chain rings in various pictures.

The big ring in the end of the crank to which the pedal shaft is
attached rotates.

Then the pedal rotates around the pedal shaft.

If the long arrangment gives a 175 mm crank at the bottom of the pedal
stroke, the result is that you have a weirdly shortened crank at the
top of the stroke, about 120 mm.

The picture indicates a roughly 1.75 to 2.625 ratio between the long
and short sides of the ring. A quick and dirty ruler shows 1 & 3/4
inches and 2 & 5/8 inches on my screen. Without a real crank, it's
hard to measure precisely, but you can see at a glance that the change
is large.

Since you're putting almost no force into the pedal at top dead
center, the huge reduction doesn't matter much.

Cheers,

Carl Fogel

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

Quoted message said:

<[email hidden]> wrote: I wonder what the theory is behind
the design.
^^^^^^^^^^^^^^^^

This is how I have combined reverse engineering and guesswork:

The pedals are attached to small gears, which revolve inside ring gears,

so

Quoted message said:

they stay horizontal all the time. As the cranks rotate, then, their
effective length changes from a minimum to a maximum and back again.

This

Quoted message said:

is equivalent to shifting the gearing up and down with each pedal stroke.
You can accomplish the same thing with an elliptical chainring more

simply

Quoted message said:

and with less weight. I like elliptical chainrings on my mountain
bike--Jobst says they are worthless. We would probably have the same
diagreement about these gadgets, but the weight and dollar penalty would

be

Quoted message said:

higher.

Not to mention the social stigma. These things scream "dork" -- assuming
they are not just a sizing tool.

I suspect they are not just a sizing tool (unless Muzzi is positive about
that) since they are from an era of invention (or re-invention as Carl may
point out) that included the Bio Cam (fondly called the Trash Cam), the
Browning electric front derailleur, personal teathers, a Gipiemmi pedal
with an eccentric for sizing, Rigi dual seat tubes -- and all all sorts of
other dorky things that no normal person bought. -- Jay Beattie.

Quoted message said:

On 19 May 2007 14:03:46 -0700, "[email hidden]"

Quoted message said:

Quoted message said:

On 19 May 2007 04:21:20 -0700, "[email hidden]"

Quoted message said:

Quoted message said:

<[email hidden]> wrote:
>Hi All,

Quoted message said:

Quoted message said:

>Here is an interesting item:

Quoted message said:

Quoted message said:

>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

Quoted message said:

>I wonder what the theory is behind the design.

Quoted message said:

Quoted message said:

>Joseph

Quoted message said:

Quoted message said:

Dear Joseph,

Quoted message said:

Quoted message said:

It's a modern version (like the Shimano AX) of the Ramsey Swinging
Pedal of 1898, pictured below:

Quoted message said:

Quoted message said:

http://i12.tinypic.com/5z2l4ph.jpg

Quoted message said:

Quoted message said:

Here's the theory, which is entertaining balderdash:

Quoted message said:

Quoted message said:

"Ramsey's Swinging Pedal is one of the decided novelties for 1898,
designed primarily to add to the ease of controlling a bicycle through
its driving mechanism, to render it less difficult than formerly to
catch a slipped pedal, and to allow the freest ankle motion. In
action, it transmits automatically, in conformity with the arc of the
circle described by the pedals, the applied power of the rider, thus
maintaining the full leverage of the crank over an increased arc of
that circle, converting the straight push into an improved and
automatic ankle motion. It is claimed to entirely obviate the 'dead
center,' thus avoiding the hammer blow and back lash of the chain,
developing more propelling power than can be obtained by the best
ankle motion with the ordinary pedals. The pick-up of a Ramsey pedal
is instantaneous, and momentum is gained at once; the pedal is always
right side up, and consequently the toe-clip is always ready for the
foot. With so little depth of pedal beneath the foot, the rider is
enabled to sit nearer the ground without decreasing the distance
between the ground and the pedal. Manufactured by the Ramsey Swinging
Pedal Company, Philadelphia, Pa."

Quoted message said:

Quoted message said:

Price, $5.00.

Quoted message said:

Quoted message said:

"Outing" magazine, p. 104-5

Quoted message said:

Quoted message said:

http://www.aafla.org/SportsLibrary/Outing/Volume_32/outXXXII01/outXXX...

Quoted message said:

Quoted message said:

Cheers,

Quoted message said:

Quoted message said:

Carl Fogel

Quoted message said:

That's some impressive mumbo-jumbo! Have you ever played buzz-word
bingo?

Quoted message said:

The funny thing about these pedals is they seem to be fixed to the
black rings at the forward position, and presumably the black rings
are free to rotate. At first I thought this would be a wobbly set-up
like a huge stack height, but as the pedal is fixed at the forward
position, perhaps it is in a way "self-energizing" in a way that
changes the crank length during the power stroke. I wonder if it tends
to push the pedal one way or the other in some uncomfortable way. I
might just have to find out!

Quoted message said:

Joseph

Dear Joseph,

No, they're not fixed. You can see them rotating in the different
pictures in the ad:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Look at the crank with no chain rings in various pictures.

The big ring in the end of the crank to which the pedal shaft is
attached rotates.

Then the pedal rotates around the pedal shaft.

I still think the pedal has a fixed orientation to the black ring. The
angle of the pedals relative to the black circles seems the same in
all the pictures. And if they were free to rotate why would the huge
kick-flip tabs be needed?

Quoted message said:

If the long arrangment gives a 175 mm crank at the bottom of the pedal
stroke, the result is that you have a weirdly shortened crank at the
top of the stroke, about 120 mm.

The picture indicates a roughly 1.75 to 2.625 ratio between the long
and short sides of the ring. A quick and dirty ruler shows 1 & 3/4
inches and 2 & 5/8 inches on my screen. Without a real crank, it's
hard to measure precisely, but you can see at a glance that the change
is large.

Since you're putting almost no force into the pedal at top dead
center, the huge reduction doesn't matter much.

I suppose the shape of the pedal stroke is part of the idea. If the
circles are geared (which I don't belive), the pedal path would just
be an elipse, but as I believe the circles rotate freely, the shape is
affected by the ankle angle throughout the stroke. This is where I
think the main effect of this contraption is realized: in the minor
crank length change that happens between the forward and bottom pedal
positions where force application is maximum. The large difference
that happens at TDC as you say doesn't matter and I suspect is just a
side effect.

Joseph

On 19 May 2007 23:44:04 -0700, "[email hidden]"
<[email hidden]> wrote:

[snip]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

I still think the pedal has a fixed orientation to the black ring. The
angle of the pedals relative to the black circles seems the same in
all the pictures. And if they were free to rotate why would the huge
kick-flip tabs be needed?

[snip]

Dear Joseph,

We may be misunderstanding each other.

In these two pictures, the point where the pedal attaches to the black
ring on the bare crank arm has moved about 90 degrees:

http://i10.ebayimg.com/07/i/000/9f/ag/2da1_1.JPG
http://i17.ebayimg.com/06/i/000/9f/ag/316c_1.JPG

In these two pictures, the point where the pedal attaches to the black
ring of the crank arm with the chain rings has moved about 180 degrees
(the crank is flipped from picture to picture):

http://i24.ebayimg.com/03/i/000/9f/ag/2ef5_1.JPG
http://i2.ebayimg.com/03/i/000/9f/ag/3036_1.JPG

The pedal shafts are attached to the round black rings, which rotate
freely and change the effective crank length throughout the pedal
cycle (though not with any known advantage).

Meanwhile, the pedals rotate freely on the pedal shafts, just as they
do on any normal bicycle. Otherwise, they'd throw the rider's feet off
instantly.

As for the heel plates, I shudder to think what explanations the
marketing department came up with to justify them. Probably the idea
is that the springy heel plates replace the normal straps used with
toe cages.

Cheers,

Carl Fogel

<[email hidden]> wrote: (clip) Meanwhile, the pedals rotate freely
on the pedal shafts, just as they
do on any normal bicycle. Otherwise, they'd throw the rider's feet off
instantly. (clip)
^^^^^^^^^^^^^^^^
Dear Carl--With all due respect, I think you've got it wrong. I believe
each pedal is solidly attached to a small pinion, which rolls around the
inside of a ring gear. It's like a planetary transmission without the "sun
gear." The gear ratio is chosen so that the pedals remain horizontal as the
crank turns. This action turns the rings so the effective crank length
changes.
^^^^^^^^^^^^^^^^^^
As for the heel plates, I shudder to think what explanations the marketing
department came up with to justify them.
^^^^^^^^^^^^^^^^^^
If you take your feet out of the pedals, so they are free to spin, then the
rings stop, and the long-short crank action stops. To start riding, you
would put one foot into a pedal, using the "heel plate" to help the toe to
enter. The rider is now faced with the task of inserting the other toe.
The pedal is turning at the same rate as the crank, so the rider uses the
heel plate to hold it horizontal.

Anyhow, that's how I picture it.

Quoted message said:

On 19 May 2007 23:44:04 -0700, "[email hidden]"

<[email hidden]> wrote:

[snip]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

I still think the pedal has a fixed orientation to the black ring. The
angle of the pedals relative to the black circles seems the same in
all the pictures. And if they were free to rotate why would the huge
kick-flip tabs be needed?

[snip]

Dear Joseph,

We may be misunderstanding each other.

In these two pictures, the point where the pedal attaches to the black
ring on the bare crank arm has moved about 90 degrees:

http://i10.ebayimg.com/07/i/000/9f/ag/2da1_1.JPGhttp://i17.ebayimg.com/06/i/000/9f/ag/316c_1.JPG

In these two pictures, the point where the pedal attaches to the black
ring of the crank arm with the chain rings has moved about 180 degrees
(the crank is flipped from picture to picture):

http://i24.ebayimg.com/03/i/000/9f/ag/2ef5_1.JPGhttp://i2.ebayimg.com/03/i/000/9f/ag/3036_1.JPG

The pedal shafts are attached to the round black rings, which rotate
freely and change the effective crank length throughout the pedal
cycle (though not with any known advantage).

Meanwhile, the pedals rotate freely on the pedal shafts, just as they
do on any normal bicycle. Otherwise, they'd throw the rider's feet off
instantly.

I agree it seems the black rings are free to rotate, but I still think
the pedals are fixed to the rings, and do not rotate. And as foolish
as this contraption may be, if the pedals rotated freely on their
spindles, the whole thing would be a wobbly mess that could have much
more easily been accomplished with Ramsey type pedals. And as the
black rings are free to rotate, one's feet wouldn't be thrown from the
pedals, however odd it may feel to use them! I take as further
evidence, the non-standard dust-cap indicating these are not normal
pedals. And in all the pictures, the lower back edge of the rear pedal
cage seems to be right in the center of the ring. This indicates that
the pedals always have the same orientation to the black rings. And
the huge kick-tabs that extend back past the rings rotation point
would be the only way to get the pedals upright when entering them as
they do not hang down like Ramsey pedals, but stick forward in the 3 o-
clock position (viewed from the drive side with the pedal oriented for
use). And the ad says the pedals are not removable. If the pedals
rotated freely as normal pedals why would they not use normal
removable pedals? And the fact that they made such a crazy contraption
in the first place is not an argument;-)

Quoted message said:

As for the heel plates, I shudder to think what explanations the
marketing department came up with to justify them. Probably the idea
is that the springy heel plates replace the normal straps used with
toe cages.

This crazy thing is pure quackery. No marketing involved! Reminds me
of the guy I knew who said he wanted a fixed gear bike with chainrings
and cogs on both sides so he could get power with each stroke. Maybe
he worked at Gipiemme in a former life! I still want it though.

Joseph

On May 20, 10:13 pm, "Leo Lichtman" <[email hidden]>

Quoted message said:

<[email hidden]> wrote: (clip) Meanwhile, the pedals rotate freely

on the pedal shafts, just as they
do on any normal bicycle. Otherwise, they'd throw the rider's feet off
instantly. (clip)
^^^^^^^^^^^^^^^^
Dear Carl--With all due respect, I think you've got it wrong. I believe
each pedal is solidly attached to a small pinion, which rolls around the
inside of a ring gear. It's like a planetary transmission without the "sun
gear." The gear ratio is chosen so that the pedals remain horizontal as the
crank turns. This action turns the rings so the effective crank length
changes.
^^^^^^^^^^^^^^^^^^
As for the heel plates, I shudder to think what explanations the marketing
department came up with to justify them.
^^^^^^^^^^^^^^^^^^
If you take your feet out of the pedals, so they are free to spin, then the
rings stop, and the long-short crank action stops. To start riding, you
would put one foot into a pedal, using the "heel plate" to help the toe to
enter. The rider is now faced with the task of inserting the other toe.
The pedal is turning at the same rate as the crank, so the rider uses the
heel plate to hold it horizontal.

Anyhow, that's how I picture it.

If there is a planetary gear system, how is it possible the pedals
have gotten themselves into the unrideable orientation shown in the
pictures that show the back sides of the cranks?

Joseph

Quoted message said:

Quoted message said:

<[email hidden]> wrote:
I wonder what the theory is behind the design.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Quoted message said:

"Leo Lichtman" <[email hidden]> wrote

Quoted message said:

This is how I have combined reverse engineering and guesswork:
The pedals are attached to small gears, which revolve inside ring gears,

so

Quoted message said:

they stay horizontal all the time. As the cranks rotate, then, their
effective length changes from a minimum to a maximum and back again.

This

Quoted message said:

is equivalent to shifting the gearing up and down with each pedal stroke.
You can accomplish the same thing with an elliptical chainring more

simply

Quoted message said:

and with less weight. I like elliptical chainrings on my mountain
bike--Jobst says they are worthless. We would probably have the same
diagreement about these gadgets, but the weight and dollar penalty would

be

Quoted message said:

higher.

Jay Beattie said:

Not to mention the social stigma. These things scream "dork" -- assuming
they are not just a sizing tool.

I suspect they are not just a sizing tool (unless Muzi is positive about
that) since they are from an era of invention (or re-invention as Carl may
point out) that included the Bio Cam (fondly called the Trash Cam), the
Browning electric front derailleur, personal teathers, a Gipiemmi pedal
with an eccentric for sizing, Rigi dual seat tubes -- and all all sorts of
other dorky things that no normal person bought. -- Jay Beattie.

You may be right (surely regarding dorkiness!). I speculated, as I
didn't see any useful advantage otherwise. That design can't achieve the
below-spindle feature of an AX pedal or Carl's referenced pre-AX Ramsey
Swinging pedal. It's a complex an dheavy way to get variable crank
length. If the black rings spin within the cranks, it's a useless
gimmick - maybe almost to the PMP level for useless extra weight.

I thought of one feature. If you _ever_ see one on the bike next to you,
it's a signal to either go a lot faster or slow down!

p.s. Browning "Beast" actually worked, and worked well.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

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

Quoted message said:

This crazy thing is pure quackery. No marketing involved! Reminds me
of the guy I knew who said he wanted a fixed gear bike with chainrings
and cogs on both sides so he could get power with each stroke. Maybe
he worked at Gipiemme in a former life! I still want it though.

I recall seeing a Pinarello brochure showing a track bike with a drivetrain
on both sides* Mind you, the hub would not be a flipflop, but RH threads on
the right side and LH threads on the left side of the hub. The left side cog
would need to be threaded LH as well. The left side lockring (for those who
would choose to use it) would need to have RH threading.

*This has been done in the past as a two speed setup for kilo riders. A
larger cog is used to facilitate quicker acceleration, the cog on the other
side is used as a top end gear.

email hidden said:

On May 20, 10:13 pm, "Leo Lichtman" <[email hidden]>

Quoted message said:

<[email hidden]> wrote: (clip) Meanwhile, the pedals rotate freely

on the pedal shafts, just as they
do on any normal bicycle. Otherwise, they'd throw the rider's feet off
instantly. (clip)
^^^^^^^^^^^^^^^^
Dear Carl--With all due respect, I think you've got it wrong. I believe
each pedal is solidly attached to a small pinion, which rolls around the
inside of a ring gear. It's like a planetary transmission without the "sun
gear." The gear ratio is chosen so that the pedals remain horizontal as the
crank turns. This action turns the rings so the effective crank length
changes.
^^^^^^^^^^^^^^^^^^
As for the heel plates, I shudder to think what explanations the marketing
department came up with to justify them.
^^^^^^^^^^^^^^^^^^
If you take your feet out of the pedals, so they are free to spin, then the
rings stop, and the long-short crank action stops. To start riding, you
would put one foot into a pedal, using the "heel plate" to help the toe to
enter. The rider is now faced with the task of inserting the other toe.
The pedal is turning at the same rate as the crank, so the rider uses the
heel plate to hold it horizontal.

Anyhow, that's how I picture it.

If there is a planetary gear system, how is it possible the pedals
have gotten themselves into the unrideable orientation shown in the
pictures that show the back sides of the cranks?

Joseph

Dear Leo & Joseph,

We may be missing each other still, so forgive me another try.

First, the black ring and the solidly attached pedal shaft rotate
inside the end of the crank.

This serves to keep the pedal spindle as close to the ground as
possible throughout the pedal cycle, changing the effective crank
length from short at the top of the pedal cycle (pedal spindle is
close to BB) to long at the bottom of the pedal cycle (pedal spindle
is far from BB).

(There's no advantage to this scheme--it's just how it works.)

Second, does the flat pedal stuck onto the pedal shaft rotate normally
around its shaft? Or is it welded solid?

Hard to tell from the text and pictures.

If you weld the pedal to its shaft, the silly thing will work like a
ferris wheel, whose seats need only one point of rotation to stay
flat.

If you stick a normal ball-bearing pedal on the shaft, it will work,
too, without any welding fuss, and it will rotate under your foot more
easily.

It's hard to tell from the pictures what was done. But the pedals
aren't at a tangent to the black ring, so it's most likely that they
aren't welded to their shafts and are rotating on normal pedal-shaft
bearings.

(Think of what happens if you weld the flat pedal at a
non-ferris-wheel-seat angle. It still works, but you end up
effectively moving the bottom bracket forward or backward. They might
have done this, but then there would really be no point.)

Anyway . . .

1) If the shaft is welded to the ring, that's integrated--you can't
remove the shaft from the ring. You end up replacing the ring and
shaft as a weird unit.

2) If the pedal is welded to the shaft, that's integrated, too--you
can't remove the shaft from the pedal, but you might be able to thread
a whole new pedal and shaft into a hole in the ring.

3) If the shaft is welded to both the ring and the pedal, that's
really integrated--you replace the whole stinking ring-shaft-pedal.

All that we can really say is that the hideous thing isn't a
three-piece scheme in which a normal pedal shaft can be unscrewed from
the black ring and the normal pedal can also be unscrewed from that
shaft--at least two of the three pieces (ring, shaft, pedal) are
permanently joined because the auction says it's "integrated."

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280116183898

Of course, I may still be missing your points, so work through it and
see what you think.

Cheers,

Carl Fogel