Funny Chain Lubricant Story

Tom Kunich' cyclintom@yahoo. com said:

An online magazine ran an article on dry lubricants. They lubed a chain and
then allowed it to swing back and forth and measured the friction on it.
After 10 minutes or so the friction would start picking up and then withina
half hour the chain would be essentially unlubricated.

I asked what happened if they tested motor oil. The comment was that it
require weeks for the chain to start getting increased friction so they
didn't want to run such tests.

What does that tell you?

that you can't compare apples to oranges, that an engine has a
enclosed drivetrain and a bike has an exposed drivetrain; the dry lube
is to help prevent accumulation of gunk; further, the chaindrive is
something like 99% efficient, so you can basically do whatever you
like- the difference is how messy do you really want to get ?

On Thu, 12 Jun 2008 13:43:15 -0700, "Tom Kunich" <cyclintom@yahoo.

com said:

An online magazine ran an article on dry lubricants. They lubed a chain and
then allowed it to swing back and forth and measured the friction on it.
After 10 minutes or so the friction would start picking up and then within a
half hour the chain would be essentially unlubricated.

I asked what happened if they tested motor oil. The comment was that it
require weeks for the chain to start getting increased friction so they
didn't want to run such tests.

What does that tell you?

Dear Tom,

It may tell us that the online magazine mis-measured friction.

Spicer tested lubricated and unlubricated bicycle chains in 2000 and
found that lubrication had no significant effect on transmission
efficiency--even when the lubricant was removed by cleaning.

After testing a chain with Castrol Wrench Force Dry Lube, Pedro’s Syn
Lube, Generation 4 White Lightning, Spicer thoroughly cleaned the
chain and tested it dry.

No significant differences were noted by his testing equipment:

"However, these results also indicate that the actual lubricant used
has little effect on the overall performance of the drive under
laboratory conditions given the precision of the measurement.
In addition, the chain used for the lubrication study was fully
degreased and was re-tested for efficiency. This degreasing operation
consisted of a five-minute scrub with kerosene followed by a cleaning
with Castrol Degreaser. The measured efficiency of the de-lubricated
chain for the 52–15 combination at 60 RPM and 100 W was 90.3% and at
200 W was 96.5%. These efficiencies are essentially the same as those
measured for the chain in the re-lubricated condition."

It's the first article here:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

Cheers,

Carl Fogel

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

Quoted message said:

Spicer tested lubricated and unlubricated bicycle chains in 2000 and
found that lubrication had no significant effect on transmission
efficiency--even when the lubricant was removed by cleaning.

After testing a chain with Castrol Wrench Force Dry Lube, Pedro's Syn
Lube, Generation 4 White Lightning, Spicer thoroughly cleaned the
chain and tested it dry.

No significant differences were noted by his testing equipment:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

That's pretty interesting. You do understand that the idea of testing a
CLEAN chain isn't of much use? Or that lubrication is supposed to allow the
chain to run low friction despite dirt etc. in the mechanism?

On Thu, 12 Jun 2008 15:16:05 -0700, "Tom Kunich" <cyclintom@yahoo.

com said:

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

Quoted message said:

Spicer tested lubricated and unlubricated bicycle chains in 2000 and
found that lubrication had no significant effect on transmission
efficiency--even when the lubricant was removed by cleaning.

After testing a chain with Castrol Wrench Force Dry Lube, Pedro's Syn
Lube, Generation 4 White Lightning, Spicer thoroughly cleaned the
chain and tested it dry.

No significant differences were noted by his testing equipment:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

That's pretty interesting. You do understand that the idea of testing a
CLEAN chain isn't of much use? Or that lubrication is supposed to allow the
chain to run low friction despite dirt etc. in the mechanism?

Dear Tom,

As Spicer's testing showed, lubrication has next to no effect on
bicycle chain transmission efficiency.

The chief effect of lubrication on bicycle chains is to keep grit out.

Anyone can read Spicer's test:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

Maybe you can tell us more about whatever test you had in mind.

Cheers,

Carl Fogel

Quoted message said:

The chief effect of lubrication on bicycle chains is to keep grit out.

I'd have said the chief effect of lubrication is to trap the grit on
the chain, and distribute it on other parts of the bike. And the
rider's leg.

That's been true of every wet lube I've tried, anyway.

- Frank Krygowski

Frank Krygowski said:

Quoted message said:

The chief effect of lubrication on bicycle chains is to keep grit out.

I'd have said the chief effect of lubrication is to trap the grit on
the chain, and distribute it on other parts of the bike. And the
rider's leg.

That's been true of every wet lube I've tried, anyway.

- Frank Krygowski

Dear Frank,

Wet lube initially keeps road dust out. (Nothing larger will fit
between pins and rollers.)

Any wet lube traps the road dust flung up by the tires, so the wet
lube turns black within a few miles.

After that, the outside of the chain is covered with an extremely fine
polishing sludge, which gradually mixes with the thin film of clean
lube inside the rollers as the minuscule pumping action draws it in
and out.

Eventually, the area between the pins and rollers builds up a thin
layer of polishing paste.

Chain wear rates suggest how long the process takes.

Each roller turns a tiny bit as it engages the top of the front
sprocket, a tiny bit as it exits, and ditto for the rear sprocket and
any idler pulleys.

But only two of the turns are under any significant load, when the
chain is pulled onto the front sprocket and pulls off the rear
sprocket.

At 100 rpm on a 53-tooth front sprocket, the chain moves at a mere 2.5
mph. (At the same 100 rpm on a 175 mm crank, the rider's foot whirls
at a blistering 4.1 mph.)

At 100 rpm on a 53-tooth sprocket, an individual roller on a
106-roller chain makes its small partial turn under load (entering the
front or leaving the rear sprocket) at only a rate of once every
3/5ths of a second.

How small is that turn?

As it pulls onto the front 53-tooth, the roller turns and locks in
1/53rd of a circle--a bit less than 7 degrees. (About 9 degrees for a
39-tooth.) Then it just sits there until it eases off the sprocket.

The extreme case is an 11-tooth rear, where the chain pulling off has
its pin and roller turn about 32 degrees.

So an hour of 100 rpm riding produces only 6,000 partial polishing
rotations (7 to 32 degrees) on any single pin and roller, amounting to
much less than 400 full turns per hour.

That's about 0.25 rpm.

(The 106-roller chain is a convenient figure that's easy to calculate
and produces a slightly inflated result compared to the typical
~114-roller chain.)

In other words, most bicycle chains last over a thousand miles, even
on a diet of polishing paste made from oil and road dust, because the
individual pins and rollers turn so little and because the polishing
paste can contain only the grains of extremely hard road dust small
enough to fit between the pins and rollers, whose clearance is below
what a typical micrometer can measure.

As a crude example, a 53x19 at 91.5 rpm on a 2124 mm tires is doing 20
mph. Each pin on a 106-roller chain makes its partial turns under load
at 91.5 rpm, about 5500 partial polishing turns every hour or every 20
miles. That's 27,500 slight "grinds" averaging only about 20 degrees
in a thousand miles and fifty hours of steady riding at about 90 rpm.

When 25 of these pins (the ends of a foot-long ruler) wear 0.0025",
the chain elongates a full 1/16th of an inch (0.0625"😉 and should be
replaced. The 0.0025" wear on each pin-roller combination amounts to
about the thickness of a sheet of flimsy phone-book paper.

***

Such incredibly tiny wear explains why it's almost impossible to clean
real wet-lube chains that have gotten dirty.

Dunk a dirty, oily chain in solvent in an ultrasonic cleaner, shake it
in a bottle, do whatever you please--

Eventually, you'll probably run out of patience before fresh solvent
stops producing wisps of filth from what looks like an immaculate
chain.

The solvent acts only on the incredibly thin exposed edge of the film
of oil-and-grime trapped between each pin and roller, a surface that
isn't much wider than a human hair. Given such poor access, the
solvent takes forever, even with shaking or ultrasonic action, to eat
into the mess trapped between the pins and rollers.

***

Dry wax has the advantage that it draws no road dust into the
pin-roller interface. Instead of a oily film pumping in and out, the
dry lube flakes outward under pressure from between the pin and roller
and never returns.

The price for this is that the dry lube needs to be re-applied more
often than a wet lube (with exceptions of all kinds for different
lubes and conditions).

Frank is quite happy with wax that has some oil added, others swear by
various oils, and I've been reasonably pleased with Dupont Teflon
spray wax.

(I can't recommend it over oil or melted wax, but it's fairly cheap,
easy to apply, and has a pleasant new-toy effect that hasn't worn off
yet.)

***

As far as I know, lubrication makes no significant difference to chain
friction in terms of power transmission. Spicer's article explains the
theory behind this unexpected result, which could be grossly
simplified to a matter of how little actual polishing action takes
place in the lazily moving chain of a bicycle.

Even a dry chain that squeaks like a box full of bats still transmits
almost exactly the same power as a brand-new factory-lubed chain--the
noise is annoying, but it's apparently all out of proportion to the
increase in friction.

Cheers,

Carl Fogel

On 2008-06-13, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

Each roller turns a tiny bit as it engages the top of the front
sprocket, a tiny bit as it exits, and ditto for the rear sprocket and
any idler pulleys.

But only two of the turns are under any significant load, when the
chain is pulled onto the front sprocket and pulls off the rear
sprocket.

At 100 rpm on a 53-tooth front sprocket, the chain moves at a mere 2.5
mph. (At the same 100 rpm on a 175 mm crank, the rider's foot whirls
at a blistering 4.1 mph.)

At 100 rpm on a 53-tooth sprocket, an individual roller on a
106-roller chain makes its small partial turn under load (entering the
front or leaving the rear sprocket) at only a rate of once every
3/5ths of a second.

How small is that turn?

As it pulls onto the front 53-tooth, the roller turns and locks in
1/53rd of a circle--a bit less than 7 degrees. (About 9 degrees for a
39-tooth.) Then it just sits there until it eases off the sprocket.

The extreme case is an 11-tooth rear, where the chain pulling off has
its pin and roller turn about 32 degrees.

So an hour of 100 rpm riding produces only 6,000 partial polishing
rotations (7 to 32 degrees) on any single pin and roller, amounting to
much less than 400 full turns per hour.

That's about 0.25 rpm.

It is said that cross-chaining increases rate of wear. Why is that? Are
the pins still only worn as they pull on and off the front and rear
sprockets, and it's made worse by having to pull them back into line, or
do they get worn continuously in some way in a cross-chaining situation?

Ben C said:

It is said that cross-chaining increases rate of wear. Why is that? Are
the pins still only worn as they pull on and off the front and rear
sprockets, and it's made worse by having to pull them back into line, or
do they get worn continuously in some way in a cross-chaining situation?

My guess would be this: With the chain running at an angle, the loads
transmitted between links and pins (at the same parts of the chain
travel Carl describes) are not supported by the entire width of the
pin. They're supported by a larger pressure load applied to the end
of the pin, while the rest of the pin gives little help. More
pressure leads to more wear. Similar problems exist when mechanical
shafts are supported by plain bearings that are not in proper
alignment; and for shafts that are insufficiently rigid, and deflect
under load as they spin. All this stuff works better when things are
straight.

In addition, IIRC, chain efficiency is lower when the chain doesn't
run in a straight line. I imagine this is partly due to the effect I
just described, and partly because a laterally-bent chain generates
more friction between the side plates.

- Frank Krygowski

Frank Krygowski said:

Quoted message said:

It is said that cross-chaining increases rate of wear. Why is
that? Are the pins still only worn as they pull on and off the
front and rear sprockets, and it's made worse by having to pull
them back into line, or do they get worn continuously in some way
in a cross-chaining situation?

Quoted message said:

My guess would be this: With the chain running at an angle, the
loads transmitted between links and pins (at the same parts of the
chain travel Carl describes) are not supported by the entire width
of the pin. They're supported by a larger pressure load applied to
the end of the pin, while the rest of the pin gives little help.
More pressure leads to more wear. Similar problems exist when
mechanical shafts are supported by plain bearings that are not in
proper alignment; and for shafts that are insufficiently rigid, and
deflect under load as they spin. All this stuff works better when
things are straight.

Quoted message said:

In addition, IIRC, chain efficiency is lower when the chain doesn't
run in a straight line. I imagine this is partly due to the effect
I just described, and partly because a laterally-bent chain
generates more friction between the side plates.

Effects of running chains diagonally, between sprockets not on the
same line, is apparent from worn chain pictures on the web that show a
worn link pins that have barrel shaped wear grooves at mid section.
The depth of the wear groove at its ends indicating canted loading.

Even with more closely spaced (10) sprockets, a greater angle occurs
than was common with five slightly wider spaced sprocket. In the days
of 5-sprocket clusters riders generally used the inner chainwheel to
drive the lower three and the large chainwheel to drive the upper
three, seldom riding in extreme cross-over mode. It was once a topic
of discussion on this newsgroup, but now that 30 combinations are
possible, little consideration is given to resulting chain life,
constant cadence having higher priority regardless of what chain line
this requires.

Jobst Brandt

Quoted message said:

Frank Krygowski said:

Quoted message said:

The chief effect of lubrication on bicycle chains is to keep grit out.

I'd have said the chief effect of lubrication is to trap the grit on
the chain, and distribute it on other parts of the bike. And the
rider's leg.

That's been true of every wet lube I've tried, anyway.

- Frank Krygowski

Dear Frank,

Wet lube initially keeps road dust out. (Nothing larger will fit
between pins and rollers.)

Any wet lube traps the road dust flung up by the tires, so the wet
lube turns black within a few miles.

After that, the outside of the chain is covered with an extremely fine
polishing sludge, which gradually mixes with the thin film of clean
lube inside the rollers as the minuscule pumping action draws it in
and out.

Eventually, the area between the pins and rollers builds up a thin
layer of polishing paste.

Chain wear rates suggest how long the process takes.

Each roller turns a tiny bit as it engages the top of the front
sprocket, a tiny bit as it exits, and ditto for the rear sprocket and
any idler pulleys.

But only two of the turns are under any significant load, when the
chain is pulled onto the front sprocket and pulls off the rear
sprocket.

At 100 rpm on a 53-tooth front sprocket, the chain moves at a mere 2.5
mph. (At the same 100 rpm on a 175 mm crank, the rider's foot whirls
at a blistering 4.1 mph.)

At 100 rpm on a 53-tooth sprocket, an individual roller on a
106-roller chain makes its small partial turn under load (entering the
front or leaving the rear sprocket) at only a rate of once every
3/5ths of a second.

How small is that turn?

As it pulls onto the front 53-tooth, the roller turns and locks in
1/53rd of a circle--a bit less than 7 degrees. (About 9 degrees for a
39-tooth.) Then it just sits there until it eases off the sprocket.

The extreme case is an 11-tooth rear, where the chain pulling off has
its pin and roller turn about 32 degrees.

So an hour of 100 rpm riding produces only 6,000 partial polishing
rotations (7 to 32 degrees) on any single pin and roller, amounting to
much less than 400 full turns per hour.

That's about 0.25 rpm.

(The 106-roller chain is a convenient figure that's easy to calculate
and produces a slightly inflated result compared to the typical
~114-roller chain.)

In other words, most bicycle chains last over a thousand miles, even
on a diet of polishing paste made from oil and road dust, because the
individual pins and rollers turn so little and because the polishing
paste can contain only the grains of extremely hard road dust small
enough to fit between the pins and rollers, whose clearance is below
what a typical micrometer can measure.

As a crude example, a 53x19 at 91.5 rpm on a 2124 mm tires is doing 20
mph. Each pin on a 106-roller chain makes its partial turns under load
at 91.5 rpm, about 5500 partial polishing turns every hour or every 20
miles. That's 27,500 slight "grinds" averaging only about 20 degrees
in a thousand miles and fifty hours of steady riding at about 90 rpm.

When 25 of these pins (the ends of a foot-long ruler) wear 0.0025",
the chain elongates a full 1/16th of an inch (0.0625"😉 and should be
replaced. The 0.0025" wear on each pin-roller combination amounts to
about the thickness of a sheet of flimsy phone-book paper.

***

Such incredibly tiny wear explains why it's almost impossible to clean
real wet-lube chains that have gotten dirty.

Dunk a dirty, oily chain in solvent in an ultrasonic cleaner, shake it
in a bottle, do whatever you please--

Eventually, you'll probably run out of patience before fresh solvent
stops producing wisps of filth from what looks like an immaculate
chain.

The solvent acts only on the incredibly thin exposed edge of the film
of oil-and-grime trapped between each pin and roller, a surface that
isn't much wider than a human hair. Given such poor access, the
solvent takes forever, even with shaking or ultrasonic action, to eat
into the mess trapped between the pins and rollers.

***

Dry wax has the advantage that it draws no road dust into the
pin-roller interface. Instead of a oily film pumping in and out, the
dry lube flakes outward under pressure from between the pin and roller
and never returns.

The price for this is that the dry lube needs to be re-applied more
often than a wet lube (with exceptions of all kinds for different
lubes and conditions).

Frank is quite happy with wax that has some oil added, others swear by
various oils, and I've been reasonably pleased with Dupont Teflon
spray wax.

(I can't recommend it over oil or melted wax, but it's fairly cheap,
easy to apply, and has a pleasant new-toy effect that hasn't worn off
yet.)

***

As far as I know, lubrication makes no significant difference to chain
friction in terms of power transmission. Spicer's article explains the
theory behind this unexpected result, which could be grossly
simplified to a matter of how little actual polishing action takes
place in the lazily moving chain of a bicycle.

Even a dry chain that squeaks like a box full of bats still transmits
almost exactly the same power as a brand-new factory-lubed chain--the
noise is annoying, but it's apparently all out of proportion to the
increase in friction.

Cheers,

Carl Fogel

Aaargh! Off by more than order of magnitude!

Absolutely no idea where I came up with 0.25 rpm--probably just
looking at the wrong figure or not noticing that a numeral was missing
from a number when I punched enter. That'll teach me not to show my
work.

Slightly short 106-roller chain on 53x11, 100 rpm, single pin-turn
with each pedal stroke, once as it pulls onto front 53, once as it
exits rear 11.

Average turn in degrees is:

( (1/53 * 360) + (1/11 * 360) ) / 2

or (6.8 + 32.7 ) / 2

or ~20 degrees

At 100 rpm, there are 6,000 20-degree turns per hour, the equivalent
of (20/360) * 6,000, or 333.3 full turns in 60 minutes, which is 5.5
rpm, not the mysterious and mistaken 0.25 rpm.

Of course, 5.5 rpm is still pretty slow for polishing chain rollers.

***

A equally embarrassing pair of mistakes in basic arithmetic involve
the 53x19 at 91.5 rpm and 20 mph on a 2124 mm rear tire.

At 91.5 rpm, any pin on the slightly short 106-roller chain makes
about 5500 partial turns (5,490), so in fifty hours (1,000 miles at 20
mph) any pin goes through about 275,000 partial turns (274,500).

That's 275,000 partial turns, ten times the 27,500 that I scribbled
due to my careless, dim-witted reading of a calculator.

The other mistake is that with a 53x19, the average turn isn't ~20
degrees, it's ~13 degrees.

The average degrees for the two turns:

( (1/53) * 360 ) + ( (1/19) * 360 ) ) / 2

or (6.8 + 18.9) / 2

or only 12.9 degrees average turn for 53x19, not 20 degrees.

At 91.5 rpm, that's about 5500 13-degree turns per hour

or (13/360) * 5500 = ~200 full turns per hour, about 3 rpm.

Careless but detail-obsessed nitwits should always show their work.

Cheers,

Carl Fogel

Frank Krygowski said:

Ben C said:

It is said that cross-chaining increases rate of wear. Why is that? Are
the pins still only worn as they pull on and off the front and rear
sprockets, and it's made worse by having to pull them back into line, or
do they get worn continuously in some way in a cross-chaining situation?

My guess would be this: With the chain running at an angle, the loads
transmitted between links and pins (at the same parts of the chain
travel Carl describes) are not supported by the entire width of the
pin. They're supported by a larger pressure load applied to the end
of the pin, while the rest of the pin gives little help. More
pressure leads to more wear. Similar problems exist when mechanical
shafts are supported by plain bearings that are not in proper
alignment; and for shafts that are insufficiently rigid, and deflect
under load as they spin. All this stuff works better when things are
straight.

In addition, IIRC, chain efficiency is lower when the chain doesn't
run in a straight line. I imagine this is partly due to the effect I
just described, and partly because a laterally-bent chain generates
more friction between the side plates.

- Frank Krygowski

Dear Frank & Ben,

As Frank points out, the twisting concentrates the force at one side
and puts things out of line, which is always bad for wear--you want
the load distributed as evenly as possible.

This twisting and sideways rocking also tends to squish more of the
oil-and-dust (or water-and-mud) in and out of the chain crevices,
which encourages chain wear. Sideways flex is just plain bad because
it helps work road dust into the chain guts.

As for the related matter of efficiency, there is some loss with
cross-chaining, but it's small compared to the penalty for using
smaller gears.

The testing already mentioned by Spicer showed that offsetting
(cross-chaining 52x11, for example) produced only about 0.5% power
losses, while smaller sprockets lost about 3% more power than larger
sprockets (52x11 was about 3% less efficient than 52x21).

Big sprockets good, small sprockets bad.

The details are near Table 1 and the conclusion, after the statistics
are pondered, is that "it appears that the offset has a negligible
effect on efficiency."

http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

Cheers,

Carl Fogel

Quoted message said:

On Thu, 12 Jun 2008 15:16:05 -0700, "Tom Kunich" <cyclintom@yahoo.

com said:

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

Quoted message said:

Spicer tested lubricated and unlubricated bicycle chains in 2000 and
found that lubrication had no significant effect on transmission
efficiency--even when the lubricant was removed by cleaning.

After testing a chain with Castrol Wrench Force Dry Lube, Pedro's Syn
Lube, Generation 4 White Lightning, Spicer thoroughly cleaned the
chain and tested it dry.

No significant differences were noted by his testing equipment:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

That's pretty interesting. You do understand that the idea of testing a
CLEAN chain isn't of much use? Or that lubrication is supposed to allow the
chain to run low friction despite dirt etc. in the mechanism?

Dear Tom,

As Spicer's testing showed, lubrication has next to no effect on
bicycle chain transmission efficiency.

The chief effect of lubrication on bicycle chains is to keep grit out.

it's there to lubricate. it can't and doesn't keep grit out. if
anything, lube retains it.

Quoted message said:

Anyone can read Spicer's test:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

while that article sincerely seeks to address the causes, it's
incredibly naive in terms of reality. "degreasing" new chains is highly
ineffective because:

1. surface adsorption still retains a layer of grease/lube.

2. even if a chain were assembled without lube at the factory, it would
still have the processing lubes on it used during each component's
forming process.

the chain therefore runs with this surface layer until such time as it
wears out or otherwise becomes contaminated. this is far removed from
real world service where abrasives and water can destroy surface
lubrication and thus allow friction to become much more significant.

"true" degreasing basically involves removing a surface layer of the
material that was previously greased. if that were to be done, surface
friction welding will follow in double-quick time and friction would
become very significant very quickly. real world service in fact sees
two "true" degreasing mechanisms in action - physical abrasion and
chemical action. road grit performs the former, water the latter once
it undercuts and corrodes any surface layers.

Quoted message said:

Maybe you can tell us more about whatever test you had in mind.

http://en.wikipedia.org/wiki/Adsorption

surface chemistry has attracted a lot of attention in recent years. in
fact, i believe there was even a nobel prize for one of its research
pioneers recently.

jim beam said:

Quoted message said:

On Thu, 12 Jun 2008 15:16:05 -0700, "Tom Kunich" <cyclintom@yahoo.
com> wrote:

Quoted message said:

Quoted message said:

<[email hidden]> wrote in message
news:[email hidden]...
> Spicer tested lubricated and unlubricated bicycle chains in 2000 and
> found that lubrication had no significant effect on transmission
> efficiency--even when the lubricant was removed by cleaning.

Quoted message said:

Quoted message said:

> After testing a chain with Castrol Wrench Force Dry Lube, Pedro's Syn
> Lube, Generation 4 White Lightning, Spicer thoroughly cleaned the
> chain and tested it dry.

Quoted message said:

Quoted message said:

> No significant differences were noted by his testing equipment:
>http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf
That's pretty interesting. You do understand that the idea of testing a
CLEAN chain isn't of much use? Or that lubrication is supposed to allow the
chain to run low friction despite dirt etc. in the mechanism?

Quoted message said:

Dear Tom,

Quoted message said:

As Spicer's testing showed, lubrication has next to no effect on
bicycle chain transmission efficiency.

Quoted message said:

The chief effect of lubrication on bicycle chains is to keep grit out.

it's there to lubricate. it can't and doesn't keep grit out. if
anything, lube retains it.

Quoted message said:

Anyone can read Spicer's test:
http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

while that article sincerely seeks to address the causes, it's
incredibly naive in terms of reality. "degreasing" new chains is highly
ineffective because:

1. surface adsorption still retains a layer of grease/lube.

2. even if a chain were assembled without lube at the factory, it would
still have the processing lubes on it used during each component's
forming process.

the chain therefore runs with this surface layer until such time as it
wears out or otherwise becomes contaminated. this is far removed from
real world service where abrasives and water can destroy surface
lubrication and thus allow friction to become much more significant.

"true" degreasing basically involves removing a surface layer of the
material that was previously greased. if that were to be done, surface
friction welding will follow in double-quick time and friction would
become very significant very quickly. real world service in fact sees
two "true" degreasing mechanisms in action - physical abrasion and
chemical action. road grit performs the former, water the latter once
it undercuts and corrodes any surface layers.

Quoted message said:

Maybe you can tell us more about whatever test you had in mind.

http://en.wikipedia.org/wiki/Adsorption

surface chemistry has attracted a lot of attention in recent years. in
fact, i believe there was even a nobel prize for one of its research
pioneers recently.

The discussion hasn't mentioned protection from corrosion, but it
should have. Wear of corroded surfaces, with their dramatically
greater surface area, is much greater.

Calculations of chain efficiency are interesting, and no doubt well
done. But, they are beside the point if little energy is needed to
remove material, with abrasives, from the wearing parts of the chain.

And consider the noise. If the wear on the chain were as bad as the
noise of a squeeking drive train is offensive, you'd certainly lube
your chain.

Great feature of this group is that Carl might find the numbers to
measure just how efficiently a dry, unlubricated chain, can drive the
next rider nuts. <smile> Hint: Requires truly minimal energy.

Harry Travis

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

So, Carl, do you lube a chain or leave it dry?

On Sun, 15 Jun 2008 20:39:09 -0700, "Tom Kunich" <cyclintom@yahoo.

com said:

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

So, Carl, do you lube a chain or leave it dry?

Dear Tom,

As I said earlier in this thread, I'm now spraying my chain with
Dupont Teflon wax.

But I doubt that it's much better overall (or worse) than all the
other schemes . . .

Such as the exotic oils at incredible prices used by many happy RBT
posters and local bike shops, melted wax blended with just a hint of
an unassuming table oil (Frank's preference, with years of good
results), the liquid drip-on waxes at perfume-bottle prices that some
people swear by, or the drippings from discarded motor-oil cans
extracted from dumpsters (Jobst has mentioned doing this to stop
squeaks after rain in the Alps).

It's about $6 a can at Lowes hardware.

Like just about everyone, I end up replacing exposed chains.

My impression is that people who ride where it's wet and muddy buy
chains more often--gosh, what a surprise!

But every bike's tires stir up that invisible cloud of fine road dust,
which gets into the chain guts no matter what magic lube is used.
Small as the dust particles are, they're harder than the chain.

And the road dust particles have to be small--they can't do their
dirty work unless they fit between a new pin and roller, a space
smaller than most micrometers can measure.

Bicycle chains that run in cases last longer, partly because they're
protected a little from road dust, but mostly because most such bikes
aren't ridden very hard--the more gently you pedal, the longer the
chain lasts.

If the oil is black, it's full of road dust. Every bike chain in a
case that I've seen (not that many) was black as sin.

Some motorcycles ran primary chains in sealed oil baths (truly sealed,
not just a bike chain case). They essentially lasted forever, partly
because there was virtually no polishing action with the clean oil and
partly because they were double-row chains, which spread the load out.

It's worth noting that no one has produced a credible test showing a
chain in action transmitting significantly different power when
different lubes are used--most of the power loss is due to chordal
action, the variation in chain speed caused by straight links of chain
suddenly wrapping around the "circle" of a sprocket. That vibration is
why even the motorcycle chains running in sealed oil baths lose around
3% power.

The wear, annoying though it is, is a separate matter and doesn't cost
much power. It takes forever to polish about 0.0025" of metal off all
those rollers, and that wear depends on the road dust between the
surfaces.

Cheers,

Carl Fogel

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

Quoted message said:

Changing the speed of the chain run every time a link engages the
sprocket means accelerating and decelerating the chain run.

Acceleration and deceleration take power.

At 90 RPM on a 53x11, pins are engaging and disengaging on the top run
4770 times per minute. The chain speed change on the front 53 is
0.1976%, but 4.0507% on the 11-tooth rear.

It takes power to speed up and slow down the chain run ~ 4% almost
5,000 times per minute.

Still - what's the size of the power loss? Are you accelerating and
decelerating ONLY the single link?

Carl Fogel said:

Changing the speed of the chain run every time a link engages the
sprocket means accelerating and decelerating the chain run.

Quoted message said:

Acceleration and deceleration take power.

Don't confuse accelerating and slowing down on a bicycle with
mechanical action and losses. A swinging pendulum accelerates from
standstill to maximum speed every cycle and does so in a vacuum for a
long time, demonstrating that there is no power required.

Quoted message said:

At 90 RPM on a 53x11, pins are engaging and disengaging on the top
run 4770 times per minute. The chain speed change on the front 53
is 0.1976%, but 4.0507% on the 11-tooth rear.

Quoted message said:

It takes power to speed up and slow down the chain run ~ 4% almost
5,000 times per minute.

Where does the power go? What power does it take to slow down a
moving chain and where is it extracted from the mechanism?

Jobst Brandt

Quoted message said:

Dear Frank,

Changing the speed of the chain run every time a link engages the
sprocket means accelerating and decelerating the chain run.

Acceleration and deceleration take power.

Acceleration takes power or energy. Deceleration (in this instance)
would give back power or energy.

I'm sure we've previously discussed the idea of a bike with large-mass
wheels, like flywheels, but with the same total mass as a normal
bike. Yes, it takes more energy to accelerate the flywheel bike up to
speed, and it wouldn't be good for sprints. But if you were to point
that bike up a hill, you'd recover your acceleration energy, as it
helped prevent the bike from decelerating. It wouldn't decelerate as
quickly as a normal bike of equal total mass.

A similar industrial application is a stamping press with a large
flywheel driven by a small motor. Energy is stored in the flywheel as
the motor accelerates it up to speed. That energy is given back to
the system when the press is activated and the flywheel decelerates.

I think your chain is doing the same when it's in its deceleration
phase. I don't see that energy being wasted into heat, except for the
previously discussed pin friction during bending.

- Frank Krygowski

On 2008-06-16, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

It's worth noting that no one has produced a credible test showing a
chain in action transmitting significantly different power when
different lubes are used--most of the power loss is due to chordal
action, the variation in chain speed caused by straight links of chain
suddenly wrapping around the "circle" of a sprocket. That vibration is
why even the motorcycle chains running in sealed oil baths lose around
3% power.

So why does efficiency increase with tension? I suppose a tighter chain
vibrates less.

Thinking of your picture of the "floating" chain, you might think well
you've got to lift that dangling chain up each time it goes onto the
sprocket, but then of course it falls back down giving you the energy
back.