Chain lubrication - gearbox oil

jbuch wrote:

Your chart on viscosity is for *100C* temperature, or boiling water (212F).

Oops. Sorry about that.

I was unable to easily find the viscosity vs temperature data for the
lubricants in question.

Nor could I.

I can say though, that I have had both 90W gear lube and 10W-30
motor oil in my car's manual transmission (the shop manual calls
for the latter), and I could scarcely feel any difference in shifting,
cold or warm.


Tom Ace

jbuch wrote:
Tom Ace wrote:
Your chart on viscosity is for *100C* temperature, or boiling water (212F).

That's the right side axis. The axis on the left is for 40 degrees C.
Still a bit warm, of course - but I've ridden in that temperature.

I'm surprised, though, that they can use double axes this way. That
implies all the oils have the same change in viscosity with
temperature, i.e. the same viscosity index. I'd have thought
otherwise.


The bicycle chain at cooler temperatures experiences a different
lubrication viscosity than given by the charts.

I'm not convinced viscosity values have any importance in lubricating a
bike chain. They're certainly important in fully hydrodynamic plain
bearings (like your car's crankshaft mains) but the pivoting components
of a bike chain are entirely different.

ISTM all we're trying to do is keep a one-molecule layer of something
slippery between metal parts. Anything more than that probably does
more harm than good, by collecting and retaining grinding paste.

- Frank Krygowski

Tom Ace wrote:
jbuch wrote:


Your chart on viscosity is for *100C* temperature, or boiling water (212F).


Oops. Sorry about that.

Actually, the left hand scale listed viscosity for 40C and the right
hand side listed viscosity for 100C.

Evidently, the relationship between viscosity and temperature is somehow
pretty universal, and is built into the chart.

I think that a long time ago (20 years) I read something about like
that. To a large extent, my old memory seemes to recall that the
log(viscosity) vs temperature curves for a variety of different SAE oil
weights were parallel. That would be consistent with this left hand and
right hand viscosity/temperature scaling being correct.

I stopped playing lubrication engineer as soon as my job would let me,
and maybe a little sooner.




I was unable to easily find the viscosity vs temperature data for the
lubricants in question.


Nor could I.

I can say though, that I have had both 90W gear lube and 10W-30
motor oil in my car's manual transmission (the shop manual calls
for the latter), and I could scarcely feel any difference in shifting,
cold or warm.


Tom Ace


I wonder if the story of the different definitions of viscosity grade
for gear and automotive .... if the story is interesting and meaningful,
or just silly individualism.

Jim

--
1) Eat Till SATISFIED, Not STUFFED... Atkins repeated 9 times in the book
2) Exercise: It's Non-Negotiable..... Chapter 22 title, Atkins book
3) Don't Diet Without Supplimental Nutrients... Chapter 23 title, Atkins
book
4) A sensible eating plan, and follow it. (Atkins, Self Made or Other)

wrote:
jbuch wrote:

Tom Ace wrote:
Your chart on viscosity is for *100C* temperature, or boiling water (212F).


That's the right side axis. The axis on the left is for 40 degrees C.
Still a bit warm, of course - but I've ridden in that temperature.

I'm surprised, though, that they can use double axes this way. That
implies all the oils have the same change in viscosity with
temperature, i.e. the same viscosity index. I'd have thought
otherwise.


The bicycle chain at cooler temperatures experiences a different
lubrication viscosity than given by the charts.


I'm not convinced viscosity values have any importance in lubricating a
bike chain. They're certainly important in fully hydrodynamic plain
bearings (like your car's crankshaft mains) but the pivoting components
of a bike chain are entirely different.

ISTM all we're trying to do is keep a one-molecule layer of something
slippery between metal parts. Anything more than that probably does
more harm than good, by collecting and retaining grinding paste.

- Frank Krygowski


Yes, you are right (from what I remember from playing lubrication
engineer so many years ago).

The slow speed and allegedly high loads sometimes placed on the bicycle
chain would suggest that high pressure additives (extreme pressure ?)
might be desired to maintain an oil film under load.

Then too, I am just guessing that the contact loadings are "high" in the
lubrication sense.

--
1) Eat Till SATISFIED, Not STUFFED... Atkins repeated 9 times in the book
2) Exercise: It's Non-Negotiable..... Chapter 22 title, Atkins book
3) Don't Diet Without Supplimental Nutrients... Chapter 23 title, Atkins
book
4) A sensible eating plan, and follow it. (Atkins, Self Made or Other)

Andrew Price wrote:
On Fri, 11 Nov 2005 03:45:39 GMT, Werehatrack
wrote:


Yes, it works. Most types have an obnoxious odor, however; if your
ride must share living quarters with a Significant Other, this may
prove to be a problem.


Thanks to all who responded.

The consensus would appear to be "works, but stinks". I'll think I'll
just use ordinary engine oil instead.

1. high detergency is not as favorable in the wet.
2. less adequate e.p. package.

search tech archioves for drum roll please!!!!

CHAIN LUBE CHAIN LUBE CHAIN LUBE

for temps over 90 go with he tran oil
below try straight 50W racing synth

dirt collection? pawsibley. anwer there is clean often. also
pawsibley-dirt floats better on the higher viscosity giving less wear
if frequently cleaned

mark wrote:

"Andrew Price" wrote ...

Would car gearbox oil (HP 80 or 90) be suitable for chain lubrication,
provided the chain is left to soak long enough to enable the oil to
work into all the rollers?


I can remember being instructed to do just that in Eugene Sloane's book "The
Complete Book of Bicycling", ca 1970. Don't know how much dirt it would pick
up, but it should lubricate the chain as well as it lubricates a gearbox.

It's fine but it attracts dirt and it stinks - particularly the hypoid
stuff.

For many years I've used gearbox oil as a chain lubricant, and it works
just fine. Since I clean my chains every 300 miles or so the
"hardpack" issue isn't a major problem though I spend 15 minutes or so
cleaning cogs, chainrings and pulleys. Prior to a year or so ago I'd
heat the oil in a large can on an old popcorn popper (hot plate) and
let the chain soak in it for several hours. After letting it "drip
dry" overnight I'd wipe the chain down with a rag.

For the last year or so I've changed my technique. Now, I string the
chain horizontally over my workbench (I use SRAM connectors so the
chain is stretched its full length) and use an oil can to put a drop or
two of gearbox oil on each roller. After it sits overnight I wipe it
down. The new technique results in less oil on the parts of the chain
that don't really need oil, and less oil sling on other parts of the
bike. Lubrication efficacy seems to be the same.

Tom Young