Chain stretch - actual tech.

On Feb 21, 5:13*pm, Jeff Liebermann wrote:
On Thu, 21 Feb 2013 04:58:52 -0800 (PST), thirty-six

wrote:
According to conventional wisdom, a chain should be replaced when it
stretches 1/16" out of 24 links or 1ft. *That:
* 0.0625" / 12" * 100% = 0.52%

This author recommends 0.52%
http://www.kronowit.com/bicycling/chainstretch.html
which agrees with
http://www.sheldonbrown.com/chains.html
* *"If the rivet is 1/16" past the mark, you should replace
* *the chain, but the sprockets are probably undamaged."

Again, it's uncertain if the measured deformation is permanent
(plastic) or temporary (elastic).

I'm beginning to wonder if the test is really a measurement of how
much force it takes to squeeze the lubricant out of the bushings.
31 links should be:
* 31 * 0.500in/link * 25.4mm/in = 393.7mm
If the chains were packed with grease or wax, the initial 10Kg load
should be less than 393.7mm. *However, they're all greater, which
eliminates that theory. *Oh well.

2% stretch is recommended as the limit by Wipperman (but perhaps not
strictly apply with silly small teeth on modern multi-sprocket
bikes). *For 99% of the time all the chains will be below that level
of elongation taking both wear and active load into account.

It's Wippermann with 2 n's at the end. *Having a similar last name
makes me rather sensitive to such creative spelling.

2% seems rather high, unless the sprocket teeth are correspondingly
worn.

Wippermann tool, which seems to be a go/no-go test, without any
measurements:
http://www.cantitoeroad.com/chain-wear-indicator-stainless-steel-wipp...

When they sponsored a chain wear test, a run-in test was performed
before making measurements. *However, there's no indication that they
did that in this static test.
http://www.youtube.com/watch?v=RGjcD8xEu8o
The chains were considered to have failed at 1% elongation.

I'll not be loading the chain of my "racing" bike with a consistent
load of 150kg anytime soon.

It's more realistic to measure the load at which one can sustain (for
at least 10 minutes) with purely nasal breathing.

I would prefer to see a range of loads extending to well beyond what a
human could possibly produce so I can see where the curve is going. *I
also would like to see deformation IN BOTH DIRECTIONS forming
something like the usual stress/strain hysteresis curve. *That is used
to show both plastic and elastic deformation. *Three data points is
not sufficient to generate a meaningful trend line or hysteresis
curve. *In addition, it would be nice to be sure that they were
measuring chain stretch and not lubricant compression, which would
require a solvent bath to remove the lube before testing.

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558

Look, here's the simple answer. When the excess grease has been
pushed out, drip in a MoS2 solution and ride. After 10 mile+ add a
little more and cover it with a waxy lube. The waxy stuff stops the
crap getting in and the MoS2 moves onto the metal to provide superior
lubrication as the original grease fails. See if it needs some more
waxy stuff ievery 3 months or 3000 miles. After 2 years or 20,000
miles, clean the chain with paraffin oil, apply MoS2 and waxy stuff on
top. keep to the 3 month/3000 mile check and waxy top up. Replace
chain when you think the scratched plating is getting on your nerves.

On Fri, 22 Feb 2013 08:31:20 +1100, James wrote:

On 22/02/13 06:37, davethedave wrote:
On Thu, 21 Feb 2013 18:35:49 +1100, James wrote:

I just came across this;

http://www.cantitoeroad.com/docs/connex_by_wippermann/
Chains_Stretch.pdf

I can't see whether the stretch was plastic or elastic. The length
doesn't appear to have been measured again with a 10kg load.

If it's plastic ... ouch! I hope it's not. I don't think it can be.

0.5% under 150 kg load. 39 tooth CR has a radius of about 79mm, and
175mm cranks gives a force multiplier of 2.2. A 75kg dude could
easily stretch a stretchy chain 0.5% just by standing on the pedals.

Wow! Manufacturer in manufacturer funded, manufacturer conducted
research proves our **** doesn't stink shocker!

It's right up there with a certain bicycle light manufacturer, eh?

Are you implying it all sounds a bit like BUM.

Still, when it's the only test around... Or are there independent chain
tests available that you know of?

shrugs eloquently

Doesn't really deal with the stretch issue but here is good for chain
info friction wise. (watt weenies)
http://www.friction-facts.com/

And for the weight weenies.
http://weightweenies.starbike.com/li...hp?type=chains

I'd probably just buy a Wipperman anyway due to the nice side plate shape
and general all round good reputation. I'm kind of set on the teflon one
in blue to match my frame for my next chain.

But... When anyone starts throwing self funded pseudo science at anything
I immediately get a bit sceptical of the results. Call me a cynic if you
will.
--
davethedave

On 22/02/13 04:13, Jeff Liebermann wrote:

I would prefer to see a range of loads extending to well beyond what a
human could possibly produce so I can see where the curve is going. I
also would like to see deformation IN BOTH DIRECTIONS forming
something like the usual stress/strain hysteresis curve. That is used
to show both plastic and elastic deformation. Three data points is
not sufficient to generate a meaningful trend line or hysteresis
curve. In addition, it would be nice to be sure that they were
measuring chain stretch and not lubricant compression, which would
require a solvent bath to remove the lube before testing.


Agree. They would need to measure the chain length before, during and
after each higher test load - where the before and after measurement is
made with a preload. E.g.

Load(kg) Length (mm)
10 X
25 X+0.1
10 X
50 X+0.2
10 X
75 X+0.3
10 X+0.01
100 X+0.4
10 X+0.03

etc. up to say 900kg?

According to
http://www.cantitoeroad.com/docs/con...st_Results.pdf
10s chains break at about 10,000N, or about 1000kg.

Makes you wonder at what load the plastic deformation starts.

There's a directory of tests..

http://www.cantitoeroad.com/docs/connex_by_wippermann/

--
JS.

On 22/02/13 09:18, davethedave wrote:
On Fri, 22 Feb 2013 08:31:20 +1100, James wrote:

On 22/02/13 06:37, davethedave wrote:
On Thu, 21 Feb 2013 18:35:49 +1100, James wrote:

I just came across this;

http://www.cantitoeroad.com/docs/connex_by_wippermann/
Chains_Stretch.pdf

I can't see whether the stretch was plastic or elastic. The length
doesn't appear to have been measured again with a 10kg load.

If it's plastic ... ouch! I hope it's not. I don't think it can be.

0.5% under 150 kg load. 39 tooth CR has a radius of about 79mm, and
175mm cranks gives a force multiplier of 2.2. A 75kg dude could
easily stretch a stretchy chain 0.5% just by standing on the pedals.

Wow! Manufacturer in manufacturer funded, manufacturer conducted
research proves our **** doesn't stink shocker!

It's right up there with a certain bicycle light manufacturer, eh?

Are you implying it all sounds a bit like BUM.

Would I do a thing like that? Well, maybe ...

Still, when it's the only test around... Or are there independent chain
tests available that you know of?

shrugs eloquently

Doesn't really deal with the stretch issue but here is good for chain
info friction wise. (watt weenies)
http://www.friction-facts.com/

Yes, I've read his stuff.

And for the weight weenies.
http://weightweenies.starbike.com/li...hp?type=chains

And theirs.

I'd probably just buy a Wipperman anyway due to the nice side plate shape
and general all round good reputation. I'm kind of set on the teflon one
in blue to match my frame for my next chain.

Looking good is all part of the game.

But... When anyone starts throwing self funded pseudo science at anything
I immediately get a bit sceptical of the results. Call me a cynic if you
will.

Totally agree. And Wippermann have good reason to perform the tests.

When will Shimano fund a test? Maybe when masses ditch their CN-7900
chains in favour of a Wippermann chain. I.e., not any time soon ;-)

--
JS.

On Feb 21, 11:14*pm, James wrote:
On 22/02/13 04:13, Jeff Liebermann wrote:

I would prefer to see a range of loads extending to well beyond what a
human could possibly produce so I can see where the curve is going. *I
also would like to see deformation IN BOTH DIRECTIONS forming
something like the usual stress/strain hysteresis curve. *That is used
to show both plastic and elastic deformation. *Three data points is
not sufficient to generate a meaningful trend line or hysteresis
curve. *In addition, it would be nice to be sure that they were
measuring chain stretch and not lubricant compression, which would
require a solvent bath to remove the lube before testing.

Agree. *They would need to measure the chain length before, during and
after each higher test load - where the before and after measurement is
made with a preload. *E.g.

Load(kg) * * * *Length (mm)
10 * * * * * * *X
25 * * * * * * *X+0.1
10 * * * * * * *X
50 * * * * * * *X+0.2
10 * * * * * * *X
75 * * * * * * *X+0.3
10 * * * * * * *X+0.01
100 * * * * * * X+0.4
10 * * * * * * *X+0.03

etc. *up to say 900kg?

According tohttp://www.cantitoeroad.com/docs/connex_by_wippermann/Connex_Breaking...
10s chains break at about 10,000N, or about 1000kg.

Makes you wonder at what load the plastic deformation starts.

There's a directory of tests..

http://www.cantitoeroad.com/docs/connex_by_wippermann/

--
JS.

Since 1950s, no-one with extensive experience of commercial chain
drives would consider the Wippermann bicycle chain test to be an
accurate representation of permitted working condition in western
Europe. Use a feckin chaincase to block the sand and water spray,
simple-as.

On Feb 21, 2:35*am, James wrote:
I just came across this;

http://www.cantitoeroad.com/docs/con...ns_Stretch.pdf

I can't see whether the stretch was plastic or elastic. *The length
doesn't appear to have been measured again with a 10kg load.

If it's plastic ... ouch! *I hope it's not. *I don't think it can be.

0.5% under 150 kg load. *39 tooth CR has a radius of about 79mm, and
175mm cranks gives a force multiplier of 2.2. *A 75kg dude could easily
stretch a stretchy chain 0.5% just by standing on the pedals.

OK. Of course it's elastic deformation. And of course, a chain with
beefier side plates like the Wipperman will give less elastic
deformation than a chain with less beefy sideplates. The downside
would be the difference in weight of the beefier chain.

The part of their spiel that is deceptive is the claim that the
stretch causes a loss of energy, or at least a significant loss of
energy. That's not likely, IMO.

For example, as a thought experiment: 1) Replace the chain with
something really stretchy (like a long, fairly stiff spring); 2) say
it stretched enough to allow you to push the pedal from the 3 o'clock
position to the 6 o'clock position while holding the wheel stationary;
3) then hold the pedal in that position.

You'd have put work (or energy) into the system by stretching the
spring. The spring would give it back by cranking the wheel around.
The only loss due to the stretch would be the tiny friction loss
within the spring molecules.

Same thing for the chain - where would energy be lost? Where's the
friction in the stretch-unstretch cycle?

Yet another negligible problem in bicycling.

- Frank Krygowski

chain isnot gonna give energy back at the 'effective' nuerallly perceived moment...chain has no brain

TM is taking us down.

On Feb 22, 4:11*am, Frank Krygowski wrote:
On Feb 21, 2:35*am, James wrote:

I just came across this;

http://www.cantitoeroad.com/docs/con...ns_Stretch.pdf

I can't see whether the stretch was plastic or elastic. *The length
doesn't appear to have been measured again with a 10kg load.

If it's plastic ... ouch! *I hope it's not. *I don't think it can be.

0.5% under 150 kg load. *39 tooth CR has a radius of about 79mm, and
175mm cranks gives a force multiplier of 2.2. *A 75kg dude could easily
stretch a stretchy chain 0.5% just by standing on the pedals.

OK. *Of course it's elastic deformation. *And of course, a chain with
beefier side plates like the Wipperman will give less elastic
deformation than a chain with less beefy sideplates. *The downside
would be the difference in weight of the beefier chain.

Are you jesting?
That's the first time I've heard such a notion from someone with
evidence of 3 brain cells. Did one go on holiday?


The part of their spiel that is deceptive is the claim that the
stretch causes a loss of energy, or at least a significant loss of
energy. *That's not likely, IMO.

The loss is due to overcoming the friction of the roller riding up the
sprocket tooth.

For example, as a thought experiment: *1) Replace the chain with
something really stretchy (like a long, fairly stiff spring); 2) say
it stretched enough to allow you to push the pedal from the 3 o'clock
position to the 6 o'clock position while holding the wheel stationary;
3) then hold the pedal in that position.

You'd have put work (or energy) into the system by stretching the
spring. *The spring would give it back by cranking the wheel around.
The only loss due to the stretch would be the tiny friction loss
within the spring molecules.

When does that brain cell return from holiday?


Same thing for the chain - where would energy be lost? *Where's the
friction in the stretch-unstretch cycle?

Yet another negligible problem in bicycling.

So where do you believe the energy that wears away sprocket teeth come
from, anti-gravity?

On Friday, February 22, 2013 11:35:58 AM UTC-5, thirty-six wrote:
On Feb 22, 4:11*am, Frank Krygowski wrote:

On Feb 21, 2:35*am, James wrote:



I just came across this;



http://www.cantitoeroad.com/docs/con...ns_Stretch.pdf



I can't see whether the stretch was plastic or elastic. *The length

doesn't appear to have been measured again with a 10kg load.



If it's plastic ... ouch! *I hope it's not. *I don't think it can be.



0.5% under 150 kg load. *39 tooth CR has a radius of about 79mm, and

175mm cranks gives a force multiplier of 2.2. *A 75kg dude could easily

stretch a stretchy chain 0.5% just by standing on the pedals.



OK. *Of course it's elastic deformation. *And of course, a chain with

beefier side plates like the Wipperman will give less elastic

deformation than a chain with less beefy sideplates. *The downside

would be the difference in weight of the beefier chain.



Are you jesting?

That's the first time I've heard such a notion from someone with

evidence of 3 brain cells. Did one go on holiday?





The part of their spiel that is deceptive is the claim that the

stretch causes a loss of energy, or at least a significant loss of

energy. *That's not likely, IMO.



The loss is due to overcoming the friction of the roller riding up the

sprocket tooth.



For example, as a thought experiment: *1) Replace the chain with

something really stretchy (like a long, fairly stiff spring); 2) say

it stretched enough to allow you to push the pedal from the 3 o'clock

position to the 6 o'clock position while holding the wheel stationary;

3) then hold the pedal in that position.



You'd have put work (or energy) into the system by stretching the

spring. *The spring would give it back by cranking the wheel around.

The only loss due to the stretch would be the tiny friction loss

within the spring molecules.



When does that brain cell return from holiday?





Same thing for the chain - where would energy be lost? *Where's the

friction in the stretch-unstretch cycle?



Yet another negligible problem in bicycling.



So where do you believe the energy that wears away sprocket teeth come

from, anti-gravity?

eyahahahha go easy on the peanut butter

On Feb 23, 12:18*am, datakoll wrote:
On Friday, February 22, 2013 11:35:58 AM UTC-5, thirty-six wrote:
On Feb 22, 4:11*am, Frank Krygowski wrote:

On Feb 21, 2:35*am, James wrote:

I just came across this;

http://www.cantitoeroad.com/docs/con...s_Stretch..pdf

I can't see whether the stretch was plastic or elastic. *The length

doesn't appear to have been measured again with a 10kg load.

If it's plastic ... ouch! *I hope it's not. *I don't think it can be.

0.5% under 150 kg load. *39 tooth CR has a radius of about 79mm, and

175mm cranks gives a force multiplier of 2.2. *A 75kg dude could easily

stretch a stretchy chain 0.5% just by standing on the pedals.

OK. *Of course it's elastic deformation. *And of course, a chain with

beefier side plates like the Wipperman will give less elastic

deformation than a chain with less beefy sideplates. *The downside

would be the difference in weight of the beefier chain.

Are you jesting?

That's the first time I've heard such a notion from someone with

evidence of 3 brain cells. *Did one go on holiday?

The part of their spiel that is deceptive is the claim that the

stretch causes a loss of energy, or at least a significant loss of

energy. *That's not likely, IMO.

The loss is due to overcoming the friction of the roller riding up the

sprocket tooth.

For example, as a thought experiment: *1) Replace the chain with

something really stretchy (like a long, fairly stiff spring); 2) say

it stretched enough to allow you to push the pedal from the 3 o'clock

position to the 6 o'clock position while holding the wheel stationary;

3) then hold the pedal in that position.

You'd have put work (or energy) into the system by stretching the

spring. *The spring would give it back by cranking the wheel around..

The only loss due to the stretch would be the tiny friction loss

within the spring molecules.

When does that brain cell return from holiday?

Same thing for the chain - where would energy be lost? *Where's the

friction in the stretch-unstretch cycle?

Yet another negligible problem in bicycling.

So where do you believe the energy that wears away sprocket teeth come

from, anti-gravity?

eyahahahha go easy on the peanut butter

It was the two coffees and no food for breakfast. Couldn't eat and
was ill all day. I would apologise if I didn't believe he goes out of
his way to be ignorant.