Elliptical Chainrings

In article ,
Sir Gregory Hall, Esq· åke wrote:
"none (Yannick Tremblay)" yatremblay@bel1lin202. wrote in message
...
In article ,
Steve Freides wrote:
none (Yannick Tremblay) wrote:

So basically, if we turn the pedals 22.5 degree (along the circular
movement of the pedal), the amount the chain will be pulled depends on
the position of the square.

0 to 22.5 deg = 41.4mm =~ 414 teeth
22.5 to 45 deg = 58.6mm =~ 586 teeth
45 to 67.5 = 58.6mm =~ 586 teeth
67.5 to 90 = 41.4mm =~ 414 teeth

-11.25 to 11.25 deg = 39.8mm =~ 398 teeth
11.25 to 33.75 deg = 46.9mm =~ 469 teeth
33.75 to 56.25 = 66.4mm =~ 664 teeth
56.25 to 78.75 = 46.9mm =~ 469 teeth

There is still exactly 200.0mm per 90 degree but some subsections
result in more mm. There's still exactly 2000 teeth per 90 degree
rotation and 8000 teeth per 360 degree.

7: elipse, ovoid or any other shape:

The same principle applies. The maths just become a bit more
complicated and you may need infinite series to get the exact result.
Visually, it is noticeable looking at:
http://en.wikipedia.org/wiki/File:Pa...ic_ellipse.gif
that the speed of travel of the point on the circle is constant but
the speed of travel of the point on the elipse varies, sometime being
faster and sometimes slower. This is also what happens would happen
to a chain on an elipse.

If you want more details, you could look at papers such as:
http://www.noncircularchainring.be/p...elease%202.pdf
The purely mechanical section of this paper is irrefutable. They
compute the angular velocity of various chainrig using AutoCAD and
MATLAB. The biomechanical section where they produce an equation to
model the human is where there is room for interpretation.

Some manufacturers also have literature on their site on the subject.

Yannick
(sorry about the long message but this is not pantomine, this is
science and facts)

This makes some sense to me. What you are saying is that a non-round
chainring will pull more, or fewer, chain links/teeth through a
particular section of the pedalling circle, effectively changing the
gearing during the time - more chain pulled is the same as having a
stiffer, bigger gear, and less chain pulled is the same as having a
smaller gear.

Yes

So the net effect, you're saying, is to give an easier to pedal, smaller
gear where we we are weakest in the pedalling cicle, and a stiffer gear
where we have more strength - is that what you're saying?

Yes
(depending on the specific shape of the rig and the specific
alignment.)



It sounds good in theory but the theory cannot be proven
because it's wrong. The ONLY thing that determines
gearing in number of teeth. Not changing the number
of teeth (as in upshifting and downshifting to change
the number of teeth) will cause the gear ratio to remain
the same. Any illusion that an elliptical chainring pulling
more or less chain teeth at any given time is an illusion.
It's not the diameter of the chainring at the ingress
or egress of the chain from the chainring time that matters
but rather the number of teeth that will maintain the
same gear ratio no matter the shape.

An ellipse with 53 teeth is no different than a circle with
53 teeth when it comes to gear ratio. There is no way
to get some increased or reduced gear ratio without
changing the number of teeth.

I am sorry. I've gone through the long explanation for the benefit of
peoples that were confused but wanted to learn. You are welcome to
close your eyes, put your fingers in your ear and yell "NO! NO! NO!"
forever.

Your anti-eliptical chain rig position would be a lot more credible if
you'd accept the hard proven facts that there is a mechanical difference in
the pedal-front rig-chain-cassette-whell assembly but that this
mechanical difference does lead to a biomechanical advantage once you
add the cyclist into the equation.

This last part has certainly not been proven despite some attempts at
modelling it and some experimental studies (some of them sponsored by
manufacturers).

Unfortunately your current position is like claiming that the Earth is
flat.

Regards
Yan

On 24/07/2013 12:18 AM, atriage wrote:
On 24/07/2013 01:03, Sir Gregory Hall, Esq· wrote:
"none (Yannick Tremblay)" yatremblay@bel1lin202. wrote in message
...
In article ,
Steve Freides wrote:
none (Yannick Tremblay) wrote:

So basically, if we turn the pedals 22.5 degree (along the circular
movement of the pedal), the amount the chain will be pulled depends on
the position of the square.

0 to 22.5 deg = 41.4mm =~ 414 teeth
22.5 to 45 deg = 58.6mm =~ 586 teeth
45 to 67.5 = 58.6mm =~ 586 teeth
67.5 to 90 = 41.4mm =~ 414 teeth

-11.25 to 11.25 deg = 39.8mm =~ 398 teeth
11.25 to 33.75 deg = 46.9mm =~ 469 teeth
33.75 to 56.25 = 66.4mm =~ 664 teeth
56.25 to 78.75 = 46.9mm =~ 469 teeth

There is still exactly 200.0mm per 90 degree but some subsections
result in more mm. There's still exactly 2000 teeth per 90 degree
rotation and 8000 teeth per 360 degree.

7: elipse, ovoid or any other shape:

The same principle applies. The maths just become a bit more
complicated and you may need infinite series to get the exact result.
Visually, it is noticeable looking at:
http://en.wikipedia.org/wiki/File:Pa...ic_ellipse.gif
that the speed of travel of the point on the circle is constant but
the speed of travel of the point on the elipse varies, sometime being
faster and sometimes slower. This is also what happens would happen
to a chain on an elipse.

If you want more details, you could look at papers such as:
http://www.noncircularchainring.be/p...elease%202.pdf

The purely mechanical section of this paper is irrefutable. They
compute the angular velocity of various chainrig using AutoCAD and
MATLAB. The biomechanical section where they produce an equation to
model the human is where there is room for interpretation.

Some manufacturers also have literature on their site on the subject.

Yannick
(sorry about the long message but this is not pantomine, this is
science and facts)

This makes some sense to me. What you are saying is that a non-round
chainring will pull more, or fewer, chain links/teeth through a
particular section of the pedalling circle, effectively changing the
gearing during the time - more chain pulled is the same as having a
stiffer, bigger gear, and less chain pulled is the same as having a
smaller gear.

Yes

So the net effect, you're saying, is to give an easier to pedal,
smaller
gear where we we are weakest in the pedalling cicle, and a stiffer gear
where we have more strength - is that what you're saying?

Yes
(depending on the specific shape of the rig and the specific
alignment.)



It sounds good in theory but the theory cannot be proven
because it's wrong. The ONLY thing that determines
gearing in number of teeth. Not changing the number
of teeth (as in upshifting and downshifting to change
the number of teeth) will cause the gear ratio to remain
the same. Any illusion that an elliptical chainring pulling
more or less chain teeth at any given time is an illusion.
It's not the diameter of the chainring at the ingress
or egress of the chain from the chainring time that matters
but rather the number of teeth that will maintain the
same gear ratio no matter the shape.

An ellipse with 53 teeth is no different than a circle with
53 teeth when it comes to gear ratio. There is no way
to get some increased or reduced gear ratio without
changing the number of teeth.


My God you're stupid.

+1

--
Chris

'Fashion is a form of ugliness so intolerable that we have to alter it
every six months.'

(Oscar Wilde.)

On 24/07/2013 13:59, Mower Man wrote:
On 24/07/2013 12:18 AM, atriage wrote:
On 24/07/2013 01:03, Sir Gregory Hall, Esq· wrote:
"none (Yannick Tremblay)" yatremblay@bel1lin202. wrote in message
...
In article ,
Steve Freides wrote:
none (Yannick Tremblay) wrote:

So basically, if we turn the pedals 22.5 degree (along the circular
movement of the pedal), the amount the chain will be pulled
depends on
the position of the square.

0 to 22.5 deg = 41.4mm =~ 414 teeth
22.5 to 45 deg = 58.6mm =~ 586 teeth
45 to 67.5 = 58.6mm =~ 586 teeth
67.5 to 90 = 41.4mm =~ 414 teeth

-11.25 to 11.25 deg = 39.8mm =~ 398 teeth
11.25 to 33.75 deg = 46.9mm =~ 469 teeth
33.75 to 56.25 = 66.4mm =~ 664 teeth
56.25 to 78.75 = 46.9mm =~ 469 teeth

There is still exactly 200.0mm per 90 degree but some subsections
result in more mm. There's still exactly 2000 teeth per 90 degree
rotation and 8000 teeth per 360 degree.

7: elipse, ovoid or any other shape:

The same principle applies. The maths just become a bit more
complicated and you may need infinite series to get the exact result.
Visually, it is noticeable looking at:
http://en.wikipedia.org/wiki/File:Pa...ic_ellipse.gif
that the speed of travel of the point on the circle is constant but
the speed of travel of the point on the elipse varies, sometime being
faster and sometimes slower. This is also what happens would happen
to a chain on an elipse.

If you want more details, you could look at papers such as:
http://www.noncircularchainring.be/p...elease%202.pdf


The purely mechanical section of this paper is irrefutable. They
compute the angular velocity of various chainrig using AutoCAD and
MATLAB. The biomechanical section where they produce an equation to
model the human is where there is room for interpretation.

Some manufacturers also have literature on their site on the subject.

Yannick
(sorry about the long message but this is not pantomine, this is
science and facts)

This makes some sense to me. What you are saying is that a non-round
chainring will pull more, or fewer, chain links/teeth through a
particular section of the pedalling circle, effectively changing the
gearing during the time - more chain pulled is the same as having a
stiffer, bigger gear, and less chain pulled is the same as having a
smaller gear.

Yes

So the net effect, you're saying, is to give an easier to pedal,
smaller
gear where we we are weakest in the pedalling cicle, and a stiffer
gear
where we have more strength - is that what you're saying?

Yes
(depending on the specific shape of the rig and the specific
alignment.)



It sounds good in theory but the theory cannot be proven
because it's wrong. The ONLY thing that determines
gearing in number of teeth. Not changing the number
of teeth (as in upshifting and downshifting to change
the number of teeth) will cause the gear ratio to remain
the same. Any illusion that an elliptical chainring pulling
more or less chain teeth at any given time is an illusion.
It's not the diameter of the chainring at the ingress
or egress of the chain from the chainring time that matters
but rather the number of teeth that will maintain the
same gear ratio no matter the shape.

An ellipse with 53 teeth is no different than a circle with
53 teeth when it comes to gear ratio. There is no way
to get some increased or reduced gear ratio without
changing the number of teeth.


My God you're stupid.

+1

At first I thought he was a troll but it seems he really believes the
**** he posts.

On Wednesday, July 24, 2013 6:56:53 AM UTC-7, atriage wrote:
On 24/07/2013 13:59, Mower Man wrote:

On 24/07/2013 12:18 AM, atriage wrote:

On 24/07/2013 01:03, Sir Gregory Hall, Esq· wrote:

"none (Yannick Tremblay)" yatremblay@bel1lin202. wrote in message

...

In article ,

Steve Freides wrote:

none (Yannick Tremblay) wrote:



So basically, if we turn the pedals 22.5 degree (along the circular

movement of the pedal), the amount the chain will be pulled

depends on

the position of the square.



0 to 22.5 deg = 41.4mm =~ 414 teeth

22.5 to 45 deg = 58.6mm =~ 586 teeth

45 to 67.5 = 58.6mm =~ 586 teeth

67.5 to 90 = 41.4mm =~ 414 teeth



-11.25 to 11.25 deg = 39.8mm =~ 398 teeth

11.25 to 33.75 deg = 46.9mm =~ 469 teeth

33.75 to 56.25 = 66.4mm =~ 664 teeth

56.25 to 78.75 = 46.9mm =~ 469 teeth



There is still exactly 200.0mm per 90 degree but some subsections

result in more mm. There's still exactly 2000 teeth per 90 degree

rotation and 8000 teeth per 360 degree.



7: elipse, ovoid or any other shape:



The same principle applies. The maths just become a bit more

complicated and you may need infinite series to get the exact result.

Visually, it is noticeable looking at:

http://en.wikipedia.org/wiki/File:Pa...ic_ellipse.gif

that the speed of travel of the point on the circle is constant but

the speed of travel of the point on the elipse varies, sometime being

faster and sometimes slower. This is also what happens would happen

to a chain on an elipse.



If you want more details, you could look at papers such as:

http://www.noncircularchainring.be/p...elease%202.pdf





The purely mechanical section of this paper is irrefutable. They

compute the angular velocity of various chainrig using AutoCAD and

MATLAB. The biomechanical section where they produce an equation to

model the human is where there is room for interpretation.



Some manufacturers also have literature on their site on the subject.



Yannick

(sorry about the long message but this is not pantomine, this is

science and facts)



This makes some sense to me. What you are saying is that a non-round

chainring will pull more, or fewer, chain links/teeth through a

particular section of the pedalling circle, effectively changing the

gearing during the time - more chain pulled is the same as having a

stiffer, bigger gear, and less chain pulled is the same as having a

smaller gear.



Yes



So the net effect, you're saying, is to give an easier to pedal,

smaller

gear where we we are weakest in the pedalling cicle, and a stiffer

gear

where we have more strength - is that what you're saying?



Yes

(depending on the specific shape of the rig and the specific

alignment.)







It sounds good in theory but the theory cannot be proven

because it's wrong. The ONLY thing that determines

gearing in number of teeth. Not changing the number

of teeth (as in upshifting and downshifting to change

the number of teeth) will cause the gear ratio to remain

the same. Any illusion that an elliptical chainring pulling

more or less chain teeth at any given time is an illusion.

It's not the diameter of the chainring at the ingress

or egress of the chain from the chainring time that matters

but rather the number of teeth that will maintain the

same gear ratio no matter the shape.



An ellipse with 53 teeth is no different than a circle with

53 teeth when it comes to gear ratio. There is no way

to get some increased or reduced gear ratio without

changing the number of teeth.





My God you're stupid.



+1



At first I thought he was a troll but it seems he really believes the

**** he posts.

You and none may have gone past the point of invoking the following ground rule.........."when you argue with a fool, chances are they are doing the same thing". Your bail out point may vary but its way passed mine.
Phil H

Phil H a écrit profondement:

| At first I thought he was a troll but it seems he really believes the
|
| **** he posts.

| You and none may have gone past the point of invoking the following
| ground rule.........."when you argue with a fool, chances are they are
| doing the same thing". Your bail out point may vary but its way passed
| mine.
| Phil H

http://azurservers.com/rbr/aoi.jpg


And trim the garbage out too.

--
Davey Crockett
Fly your Flag
http://azurservers.com/images/ptflag.png

On 26/07/2013 23:58, Phil H wrote:

At first I thought he was a troll but it seems he really believes the

**** he posts.
Your bail out point may vary but its way passed mine.

Yeah mine does vary, it's my civic duty to make sure ****s like Greg are
kept abreast of the current situation regarding their status. You may
also note that there is virtually no traffic actually concerned with
racing here anymore so ant post is gonna be OT. RBR has become a chat
room with a vaguely cycle oriented theme which I find entertaining
enough. Entertainment being the only actual point of usenet.

On 27/07/2013 03:51, Davey Crockett wrote:
Phil H a écrit profondement:

| At first I thought he was a troll but it seems he really believes the
|
| **** he posts.

| You and none may have gone past the point of invoking the following
| ground rule.........."when you argue with a fool, chances are they are
| doing the same thing". Your bail out point may vary but its way passed
| mine.
| Phil H

http://azurservers.com/rbr/aoi.jpg


And trim the garbage out too.


You wanna trim you trim, whether or not I do will depend entirely on
whether I can be arsed to at that particular moment. You have no input
on the decision.