Elliptical Chainrings

On 7/19/2013 4:07 PM, Doug Anderson wrote:
"Steve Freides" writes:

Sir Gregory Hall, Esq· wrote:

Froome mostly sits because any energy used moving the body
up and down when standing is energy wasted compared to
not lifting the body and staying seated.

Froome's height is 6 feet, 13 inches.

Maybe he isn't quite that tall.


I knew a bike shop manager who described himself as 5 foot, 20 inches
tall. He really was.

Mark J.

Mower Man wrote:
On 20/07/2013 12:07 AM, Doug Anderson wrote:
"Steve Freides" writes:

Sir Gregory Hall, Esq· wrote:

Froome mostly sits because any energy used moving the body
up and down when standing is energy wasted compared to
not lifting the body and staying seated.

Froome's height is 6 feet, 13 inches.

Maybe he isn't quite that tall.

Another LOB. How - given that there are 12 inches to a foot (FFS why
do you lot not use the metric system? Sooooo much simpler) is 6 feet
13 inches really 7 feet one inch?

LOB = Met Police slang, "Load of ********".

It was said tongue in cheek. Nudge, nudge, you know what I mean ... I
just meant that he's on the tall side.

-S-

Mower Man wrote:

Wrong. It does. And it's so obvious as to beggar belief. The slack in
the chain is utterly irrelevant, too.

Let us consider what's happening at a point in the rotation of the
chainrings where it's clearly not round. Are you suggesting there is a
different amount of pedal travel in order to advance the chain at the
rear wheel by one link? That's the crux of the issue - you are arguing,
I believe, that the amount of pedal travel varies throughout a pedaling
circle as the shape of the chainring changes - because if it doesn't,
then there is no difference.

What really could make a difference is if the shape of the chainring
effectively changed the gear ratio during a single pedal revolution. If
that happened, then we'd be talking about something tangible, the
reduction of force required by a lower gear at the point the rider's
legs were weakest. Now that sounds like it could be truly useful.

-S-

On 21/07/2013 4:35 PM, Steve Freides wrote:
Mower Man wrote:

Wrong. It does. And it's so obvious as to beggar belief. The slack in
the chain is utterly irrelevant, too.

Let us consider what's happening at a point in the rotation of the
chainrings where it's clearly not round. Are you suggesting there is a
different amount of pedal travel in order to advance the chain at the
rear wheel by one link? That's the crux of the issue - you are arguing,
I believe, that the amount of pedal travel varies throughout a pedaling
circle as the shape of the chainring changes - because if it doesn't,
then there is no difference.

What really could make a difference is if the shape of the chainring
effectively changed the gear ratio during a single pedal revolution. If
that happened, then we'd be talking about something tangible, the
reduction of force required by a lower gear at the point the rider's
legs were weakest. Now that sounds like it could be truly useful.

-S-

It is. At TDC and BDC it does.

--
Chris

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

(Oscar Wilde.)

Mower Man wrote:
On 21/07/2013 4:35 PM, Steve Freides wrote:
Mower Man wrote:

Wrong. It does. And it's so obvious as to beggar belief. The slack
in the chain is utterly irrelevant, too.

Let us consider what's happening at a point in the rotation of the
chainrings where it's clearly not round. Are you suggesting there
is a different amount of pedal travel in order to advance the chain
at the rear wheel by one link? That's the crux of the issue - you
are arguing, I believe, that the amount of pedal travel varies
throughout a pedaling circle as the shape of the chainring changes -
because if it doesn't, then there is no difference.

What really could make a difference is if the shape of the chainring
effectively changed the gear ratio during a single pedal revolution.
If that happened, then we'd be talking about something tangible, the
reduction of force required by a lower gear at the point the rider's
legs were weakest. Now that sounds like it could be truly useful.

-S-

It is. At TDC and BDC it does.

How?

Assuming the proverbial 53-tooth chainring, doesn't one full revolution
of the pedals have to move 53 links of chain? Yes, of course it does.

But the more relevant question to this discussion is: Doesn't _any_ 1/53
of a revolution of the pedals have to move 1 link of chain?

-S-

"Steve Freides" wrote in message
...
Mower Man wrote:
On 21/07/2013 4:35 PM, Steve Freides wrote:
Mower Man wrote:

Wrong. It does. And it's so obvious as to beggar belief. The slack
in the chain is utterly irrelevant, too.

Let us consider what's happening at a point in the rotation of the
chainrings where it's clearly not round. Are you suggesting there
is a different amount of pedal travel in order to advance the chain
at the rear wheel by one link? That's the crux of the issue - you
are arguing, I believe, that the amount of pedal travel varies
throughout a pedaling circle as the shape of the chainring changes -
because if it doesn't, then there is no difference.

What really could make a difference is if the shape of the chainring
effectively changed the gear ratio during a single pedal revolution.
If that happened, then we'd be talking about something tangible, the
reduction of force required by a lower gear at the point the rider's
legs were weakest. Now that sounds like it could be truly useful.

It is. At TDC and BDC it does.

How?

Assuming the proverbial 53-tooth chainring, doesn't one full revolution of
the pedals have to move 53 links of chain? Yes, of course it does.

But the more relevant question to this discussion is: Doesn't _any_ 1/53 of
a revolution of the pedals have to move 1 link of chain?



BINGO!!!!!!!!!!!! And then there's this: Advocates talk about a leverage
advantage due to the major axis of the ellipse being, in effect, a longer
lever arm. But, I maintain leverage is accounted for at the pedal and
is a result of crank arm length. Until and unless the elliptical sprocket
becomes larger along its major axis than the length of the crank arm
then no additional leverage can result from it.

On Sunday, July 21, 2013 11:43:58 AM UTC-4, Mower Man wrote:
On 21/07/2013 4:35 PM, Steve Freides wrote:

Mower Man wrote:



Wrong. It does. And it's so obvious as to beggar belief. The slack in

the chain is utterly irrelevant, too.



Let us consider what's happening at a point in the rotation of the

chainrings where it's clearly not round. Are you suggesting there is a

different amount of pedal travel in order to advance the chain at the

rear wheel by one link? That's the crux of the issue - you are arguing,

I believe, that the amount of pedal travel varies throughout a pedaling

circle as the shape of the chainring changes - because if it doesn't,

then there is no difference.



What really could make a difference is if the shape of the chainring

effectively changed the gear ratio during a single pedal revolution. If

that happened, then we'd be talking about something tangible, the

reduction of force required by a lower gear at the point the rider's

legs were weakest. Now that sounds like it could be truly useful.



-S-



It is. At TDC and BDC it does.



--

Chris



'Fashion is a form of ugliness so intolerable that we have to alter it

every six months.'



(Oscar Wilde.)

I remember Shimano saying that Bio Pace was designed to eliminate the dead zone at TDC and BDC. In other words BP allowed tthe bicyclist to maintain the same pressure on the crank arms throughout the entire revolution. The design of the eliptical rings was such that in effect there was no longer a real TDC or BDC.

Cheers

On Sunday, July 21, 2013 1:11:28 PM UTC-4, Sir Gregory Hall, Esq· wrote:
"Steve Freides" wrote in message

...

Mower Man wrote:

On 21/07/2013 4:35 PM, Steve Freides wrote:

Mower Man wrote:



Wrong. It does. And it's so obvious as to beggar belief. The slack

in the chain is utterly irrelevant, too.



Let us consider what's happening at a point in the rotation of the

chainrings where it's clearly not round. Are you suggesting there

is a different amount of pedal travel in order to advance the chain

at the rear wheel by one link? That's the crux of the issue - you

are arguing, I believe, that the amount of pedal travel varies

throughout a pedaling circle as the shape of the chainring changes -

because if it doesn't, then there is no difference.



What really could make a difference is if the shape of the chainring

effectively changed the gear ratio during a single pedal revolution.

If that happened, then we'd be talking about something tangible, the

reduction of force required by a lower gear at the point the rider's

legs were weakest. Now that sounds like it could be truly useful.



It is. At TDC and BDC it does.



How?



Assuming the proverbial 53-tooth chainring, doesn't one full revolution of

the pedals have to move 53 links of chain? Yes, of course it does.



But the more relevant question to this discussion is: Doesn't _any_ 1/53 of

a revolution of the pedals have to move 1 link of chain?







BINGO!!!!!!!!!!!! And then there's this: Advocates talk about a leverage

advantage due to the major axis of the ellipse being, in effect, a longer

lever arm. But, I maintain leverage is accounted for at the pedal and

is a result of crank arm length. Until and unless the elliptical sprocket

becomes larger along its major axis than the length of the crank arm

then no additional leverage can result from it.

I think that the idea was to change whre/how the leverage was applied. Just like when applying force to a stuck nut or bolt, the amount of leverage that can be applied by the body using the wrench increases or decreases depending where the leverage arm is located. Think of the bolt/nut as being in the center of a clock face. Depending on the hour number the handle of the lever is pointing towards can make a big difference in how much pressure one can exert on that lever. The lever length doesn't change nor does the diameter of the turning circle of that lever but the amount of leverage that can be applied does change because more force can be applied.

Cheers

wrote in message
...
On Sunday, July 21, 2013 1:11:28 PM UTC-4, Sir Gregory Hall, Esq· wrote:
"Steve Freides" wrote in message

...

Mower Man wrote:

On 21/07/2013 4:35 PM, Steve Freides wrote:

Mower Man wrote:



Wrong. It does. And it's so obvious as to beggar belief. The slack

in the chain is utterly irrelevant, too.



Let us consider what's happening at a point in the rotation of the

chainrings where it's clearly not round. Are you suggesting there

is a different amount of pedal travel in order to advance the chain

at the rear wheel by one link? That's the crux of the issue - you

are arguing, I believe, that the amount of pedal travel varies

throughout a pedaling circle as the shape of the chainring changes -

because if it doesn't, then there is no difference.



What really could make a difference is if the shape of the chainring

effectively changed the gear ratio during a single pedal revolution.

If that happened, then we'd be talking about something tangible, the

reduction of force required by a lower gear at the point the rider's

legs were weakest. Now that sounds like it could be truly useful.



It is. At TDC and BDC it does.



How?



Assuming the proverbial 53-tooth chainring, doesn't one full revolution of

the pedals have to move 53 links of chain? Yes, of course it does.



But the more relevant question to this discussion is: Doesn't _any_ 1/53
of

a revolution of the pedals have to move 1 link of chain?







BINGO!!!!!!!!!!!! And then there's this: Advocates talk about a leverage

advantage due to the major axis of the ellipse being, in effect, a longer

lever arm. But, I maintain leverage is accounted for at the pedal and

is a result of crank arm length. Until and unless the elliptical sprocket

becomes larger along its major axis than the length of the crank arm

then no additional leverage can result from it.

I think that the idea was to change whre/how the leverage was applied. Just
like when applying force to a stuck nut or bolt, the amount of leverage that
can be applied by the body using the wrench increases or decreases depending
where the leverage arm is located. Think of the bolt/nut as being in the
center of a clock face. Depending on the hour number the handle of the lever
is pointing towards can make a big difference in how much pressure one can
exert on that lever. The lever length doesn't change nor does the diameter of
the turning circle of that lever but the amount of leverage that can be
applied does change because more force can be applied.

Cheers



=====================[reply]===========================

That's all well and good but let's place an 11 tooth sprocket on the bolt or
nut. Then let's place a 53-tooth chainring on the wrench and connect them with
a chain. Then let's spin the wrench. The force applied to the wrench is
directly applied to the 53-tooth chainring and transferred via the chain to
the 11-tooth sprocket on the bolt or nut.

It is the gear ratio alone that and applies X amount of torque. It doesn't
matter one iota if the 53-tooth chainring is elliptical in shape as long as
the wrench is longer than the major axis of the elliptical chainring. The
false illusion of a different gear ration due to the placement of the
elliptical chainring belies the fact that it is still only the gear ratio that
affects the torque value.

Cheerio!

On Sunday, July 21, 2013 6:20:50 PM UTC-4, Sir Gregory Hall, Esq� wrote:
wrote in message

...

On Sunday, July 21, 2013 1:11:28 PM UTC-4, Sir Gregory Hall, Esq� wrote:

"Steve Freides" wrote in message



...



Mower Man wrote:



On 21/07/2013 4:35 PM, Steve Freides wrote:



Mower Man wrote:







Wrong. It does. And it's so obvious as to beggar belief. The slack



in the chain is utterly irrelevant, too.







Let us consider what's happening at a point in the rotation of the



chainrings where it's clearly not round. Are you suggesting there



is a different amount of pedal travel in order to advance the chain



at the rear wheel by one link? That's the crux of the issue - you



are arguing, I believe, that the amount of pedal travel varies



throughout a pedaling circle as the shape of the chainring changes -



because if it doesn't, then there is no difference.







What really could make a difference is if the shape of the chainring



effectively changed the gear ratio during a single pedal revolution..



If that happened, then we'd be talking about something tangible, the



reduction of force required by a lower gear at the point the rider's



legs were weakest. Now that sounds like it could be truly useful.







It is. At TDC and BDC it does.







How?







Assuming the proverbial 53-tooth chainring, doesn't one full revolution of



the pedals have to move 53 links of chain? Yes, of course it does.







But the more relevant question to this discussion is: Doesn't _any_ 1/53

of



a revolution of the pedals have to move 1 link of chain?















BINGO!!!!!!!!!!!! And then there's this: Advocates talk about a leverage



advantage due to the major axis of the ellipse being, in effect, a longer



lever arm. But, I maintain leverage is accounted for at the pedal and



is a result of crank arm length. Until and unless the elliptical sprocket



becomes larger along its major axis than the length of the crank arm



then no additional leverage can result from it.



I think that the idea was to change whre/how the leverage was applied. Just

like when applying force to a stuck nut or bolt, the amount of leverage that

can be applied by the body using the wrench increases or decreases depending

where the leverage arm is located. Think of the bolt/nut as being in the

center of a clock face. Depending on the hour number the handle of the lever

is pointing towards can make a big difference in how much pressure one can

exert on that lever. The lever length doesn't change nor does the diameter of

the turning circle of that lever but the amount of leverage that can be

applied does change because more force can be applied.



Cheers







=====================[reply]===========================



That's all well and good but let's place an 11 tooth sprocket on the bolt or

nut. Then let's place a 53-tooth chainring on the wrench and connect them with

a chain. Then let's spin the wrench. The force applied to the wrench is

directly applied to the 53-tooth chainring and transferred via the chain to

the 11-tooth sprocket on the bolt or nut.



It is the gear ratio alone that and applies X amount of torque. It doesn't

matter one iota if the 53-tooth chainring is elliptical in shape as long as

the wrench is longer than the major axis of the elliptical chainring. The

false illusion of a different gear ration due to the placement of the

elliptical chainring belies the fact that it is still only the gear ratio that

affects the torque value.



Cheerio!

A lot of times when trying to loosen a tight nut or bolt, if you place the handle of the wrench lower than 12 o'clock you can exert more pressure onto the handle but *NOTHING* else has changed. That's what the eliptical chainring does. It allows more force to be applied at the former deadzones of TDC and BDC. The gear size (effective diameter of a direct drive wheel) doesn't change nor does the length of tthe lever - just the amount of force that can be applied to that lever.

Cheers