Chain wear measurement

Richard McClary said:

OK, so I bought one of those Park chain checkers - not the expensive
one with the dial but the one that, similar to the Rohloff, will
either drop between worn links or not. It is marked ".075" and
".1".

Quoted message said:

This morning, I saw the .075 drop between the links for the first
time. Out of curiosity, I tried it in another spot. It not only
dropped through at .075 but at .1 as well. I "inch wormed"
throughout the whole length of chain. It only went through at .1 in
that one section. However, there was another section into which
neither side dropped...

Quoted message said:

Moral - don't just check for chain wear in one single spot.

Or better yet, don't use chain checkers because they are measuring the
wrong thing.

http://www.sheldonbrown.com/brandt/chain-care.html

# The best way to determine whether a chain is worn is by measuring
# its length. A new half inch pitch chain will have a pin at exactly
# every half inch. As the pins and sleeves wear, this spacing
# increases, concentrating more load on the last tooth of engagement
# as the chain rolls off the sprocket, thus changing the tooth
# profile. When chain pitch grows over one half percent, it is time
# for a new chain. At one percent, sprocket wear progresses rapidly
# because this length change occurs only between pin and sleeve so
# that it is concentrated on every second pitch; the pitch of the
# inner link containing the rollers remaining constant. By holding a
# ruler along the chain on the bicycle, align an inch mark with a pin
# and see how far off the mark the pin is at twelve inches. An eighth
# of an inch (0.125) is one percent, twice the sixteenth limit that is
# a prudent time for a new chain.

Jobst Brandt

Quoted message said:

Richard McClary said:

OK, so I bought one of those Park chain checkers - not the expensive
one with the dial but the one that, similar to the Rohloff, will
either drop between worn links or not. It is marked ".075" and
".1".

Quoted message said:

This morning, I saw the .075 drop between the links for the first
time. Out of curiosity, I tried it in another spot. It not only
dropped through at .075 but at .1 as well. I "inch wormed"
throughout the whole length of chain. It only went through at .1 in
that one section. However, there was another section into which
neither side dropped...

Quoted message said:

Moral - don't just check for chain wear in one single spot.

Or better yet, don't use chain checkers because they are measuring the
wrong thing.

http://www.sheldonbrown.com/brandt/chain-care.html

# The best way to determine whether a chain is worn is by measuring
# its length. A new half inch pitch chain will have a pin at exactly
# every half inch. As the pins and sleeves wear, this spacing
# increases, concentrating more load on the last tooth of engagement
# as the chain rolls off the sprocket, thus changing the tooth
# profile. When chain pitch grows over one half percent, it is time
# for a new chain. At one percent, sprocket wear progresses rapidly
# because this length change occurs only between pin and sleeve so
# that it is concentrated on every second pitch; the pitch of the
# inner link containing the rollers remaining constant. By holding a
# ruler along the chain on the bicycle, align an inch mark with a pin
# and see how far off the mark the pin is at twelve inches. An eighth
# of an inch (0.125) is one percent, twice the sixteenth limit that is
# a prudent time for a new chain.

Jobst Brandt

no, they're measuring the right thing. your method only measures pin
wear. the proper method employed by these checking devices measures
accumlated wear over pins /and/ rollers. if that is the chain
manufacturer specified measuring protocol, and it is, then stick to it.

anonymous sniped:

Quoted message said:

Quoted message said:

Quoted message said:

Moral - don't just check for chain wear in one single spot.

Quoted message said:

Quoted message said:

Or better yet, don't use chain checkers because they are measuring the
wrong thing.

Quoted message said:

Quoted message said:

http://www.sheldonbrown.com/brandt/chain-care.html

# The best way to determine whether a chain is worn is by measuring
# its length. A new half inch pitch chain will have a pin at exactly
# every half inch. As the pins and sleeves wear, this spacing
# increases, concentrating more load on the last tooth of engagement
# as the chain rolls off the sprocket, thus changing the tooth
# profile. When chain pitch grows over one half percent, it is time
# for a new chain. At one percent, sprocket wear progresses rapidly
# because this length change occurs only between pin and sleeve so
# that it is concentrated on every second pitch; the pitch of the
# inner link containing the rollers remaining constant. By holding a
# ruler along the chain on the bicycle, align an inch mark with a pin
# and see how far off the mark the pin is at twelve inches. An eighth
# of an inch (0.125) is one percent, twice the sixteenth limit that is
# a prudent time for a new chain.

Quoted message said:

no, they're measuring the right thing. your method only measures
pin wear. the proper method employed by these checking devices
measures accumlated wear over pins /and/ rollers. if that is the
chain manufacturer specified measuring protocol, and it is, then
stick to it.

The "accumulated wear" concept falls apart when considering that chain
rollers of various chain manufacturers have more or less clearance,
clearance that has no effect on sprocket engagement. It is like one
inch ID rings hung on uniformly spaced nails in a board. Their
spacing is not affected by the clearance. Tilting the board around
the nail axes has no effect on spacing.

Chain engagement is affected only by roller interval in the chain that
is given by the pins and sleeves. Roller clearance becomes zero as
the chain bears on the sprocket while roller spacing, remains 0.5"
within a roller bearing link and can only gains spacing on the wear of
pins and sleeves between these links.

That is why the chain checking devices mentioned give erroneous and
inconsistent results. The ruler does not. We recently had a good
example:

http://www.teamendorphin.com/jpg/newchain.jpg

Jobst Brandt

Quoted message said:

anonymous sniped:

Quoted message said:

Quoted message said:

>Moral - don't just check for chain wear in one single spot.

Quoted message said:

Quoted message said:

Or better yet, don't use chain checkers because they are measuring the
wrong thing.

Quoted message said:

Quoted message said:

http://www.sheldonbrown.com/brandt/chain-care.html

# The best way to determine whether a chain is worn is by measuring
# its length. A new half inch pitch chain will have a pin at exactly
# every half inch. As the pins and sleeves wear, this spacing
# increases, concentrating more load on the last tooth of engagement
# as the chain rolls off the sprocket, thus changing the tooth
# profile. When chain pitch grows over one half percent, it is time
# for a new chain. At one percent, sprocket wear progresses rapidly
# because this length change occurs only between pin and sleeve so
# that it is concentrated on every second pitch; the pitch of the
# inner link containing the rollers remaining constant. By holding a
# ruler along the chain on the bicycle, align an inch mark with a pin
# and see how far off the mark the pin is at twelve inches. An eighth
# of an inch (0.125) is one percent, twice the sixteenth limit that is
# a prudent time for a new chain.

Quoted message said:

no, they're measuring the right thing. your method only measures
pin wear. the proper method employed by these checking devices
measures accumlated wear over pins /and/ rollers. if that is the
chain manufacturer specified measuring protocol, and it is, then
stick to it.

The "accumulated wear" concept falls apart when considering that chain
rollers of various chain manufacturers have more or less clearance,
clearance that has no effect on sprocket engagement. It is like one
inch ID rings hung on uniformly spaced nails in a board. Their
spacing is not affected by the clearance. Tilting the board around
the nail axes has no effect on spacing.

Chain engagement is affected only by roller interval in the chain that
is given by the pins and sleeves. Roller clearance becomes zero as
the chain bears on the sprocket while roller spacing, remains 0.5"
within a roller bearing link and can only gains spacing on the wear of
pins and sleeves between these links.

i understand that, but i repeat, if the manufacturer specifies chain
wear with dimensions including the roller, that that's the definition of
wear! if i started redefining the gallon based on a plastic bucket i
have in the garage, it may suit me just fine, but it's no use to the
rest of the world whatsoever. fact is, measuring roller to roller can
be done with a simple tool and absolute repeatability from operator to
operator. your "eyeball" method cannot.

Quoted message said:

That is why the chain checking devices mentioned give erroneous and
inconsistent results. The ruler does not. We recently had a good
example:

http://www.teamendorphin.com/jpg/newchain.jpg

Jobst Brandt

want a pic of my bucket? it's blue.

"jim beam" wrote: (clip) if the manufacturer specifies chain wear with
dimensions including the roller, that that's the definition of wear!
^^^^^^^^^^^^^^^
If you are trying to prove excess wear in a warranty claim, then you are
probably stuck using the manufacturer's definition. If you are deciding
when to replace a chain, then the manufacturer's ideas are not binding on
you. Even if you wanted to do it by WEIGHT, that would be your perogative.

Leo Lichtman said:

"jim beam" wrote: (clip) if the manufacturer specifies chain wear with
dimensions including the roller, that that's the definition of wear!
^^^^^^^^^^^^^^^
If you are trying to prove excess wear in a warranty claim, then you are
probably stuck using the manufacturer's definition. If you are deciding
when to replace a chain, then the manufacturer's ideas are not binding on
you. Even if you wanted to do it by WEIGHT, that would be your perogative.

hey, jobst could use tarot for all i care. the point is that it needs
to be a consistent definition repeatable by ordinary busy techs just
trying to earn their buck. eyeballing against a wooden ruler [that
instrument of spectaular consistency & precision - not] is about the
worst thing you can do.

jim beam said:

Leo Lichtman said:

"jim beam" wrote: (clip) if the manufacturer specifies chain wear
with dimensions including the roller, that that's the definition of
wear! ^^^^^^^^^^^^^^^
If you are trying to prove excess wear in a warranty claim, then you
are probably stuck using the manufacturer's definition. If you are
deciding when to replace a chain, then the manufacturer's ideas are
not binding on you. Even if you wanted to do it by WEIGHT, that
would be your perogative.

hey, jobst could use tarot for all i care. the point is that it needs
to be a consistent definition repeatable by ordinary busy techs just
trying to earn their buck. eyeballing against a wooden ruler [that
instrument of spectaular consistency & precision - not] is about the
worst thing you can do.

Park CC-2 can hardly be inserted into a new Campagnolo C9 chain to get a
zero reading but reads 0.25% for a new SRAM PC59. Does the average tech
realise that? Do you call that consistent?

~PB

Quoted message said:

Even more accurate is laying a worn chain next to a new one and seeing
how many fractions of a link (1/2"😉 the old chain is longer than the
new one.

I have a friend who has a new cheap chain hanging on a finishing nail
in the garage. When he cleans the chain, he puts it on the finishing
nail on top of the new chain. Easy to see that the old chain has
"stretched". Very dramatic when you look at the total "stretch" over a
4.5 foot chain. New chains are cheaper than chain checking tools.
$7.99 for a cheap chain at Nashbar compared to $9.95 for the Park chain
checking tool. And of course the truely frugal could just have his
replacement chain hanging in the garage and use it to check for chain
wear. And then install it when the old one is "stretched". Then get a
new replacement chain and repeat. No need to squander money on a $0.39
wood ruler.

On Mon, 15 Aug 2005 15:08:11 +0100, "Pete Biggs"
<[email hidden]> wrote:

[snip]

Quoted message said:

Park CC-2 can hardly be inserted into a new Campagnolo C9 chain to get a
zero reading but reads 0.25% for a new SRAM PC59. Does the average tech
realise that? Do you call that consistent?

~PB

Dear Pete,

It sounds as if the tool is consistent, while the two brands
of chain are surprisingly different in how they would fit on
a sprocket.

http://www.parktool.com/tools/CC_2BIG.shtml

Do these chains fit sprockets very differently? Are their
rollers different sizes?

Curiously,

Carl Fogel

Quoted message said:

Pete Biggs said:

Park CC-2 can hardly be inserted into a new Campagnolo C9 chain to
get a zero reading but reads 0.25% for a new SRAM PC59. Does the
average tech realise that? Do you call that consistent?

Dear Pete,

It sounds as if the tool is consistent, while the two brands
of chain are surprisingly different in how they would fit on
a sprocket.

http://www.parktool.com/tools/CC_2BIG.shtml

Do these chains fit sprockets very differently? Are their
rollers different sizes?

Dear Carl, Just measured, both rollers look like 7.8mm to me. Perhaps
SRAM chains are supplied pre-stretched! ;-)

I did once fit a new SRAM chain that worked with worn sprockets on which a
new Campagnolo chain skipped.

~PB

Quoted message said:

I have a friend who has a new cheap chain hanging on a finishing nail
in the garage. When he cleans the chain, he puts it on the finishing
nail on top of the new chain. Easy to see that the old chain has
"stretched". Very dramatic when you look at the total "stretch" over a
4.5 foot chain. New chains are cheaper than chain checking tools.
$7.99 for a cheap chain at Nashbar compared to $9.95 for the Park chain
checking tool. And of course the truely frugal could just have his
replacement chain hanging in the garage and use it to check for chain
wear. And then install it when the old one is "stretched". Then get a
new replacement chain and repeat. No need to squander money on a $0.39
wood ruler.

This is one of the more interesting and useful suggestions I've seen
lately. Think it may be catching?

Pat Lamb said:

Quoted message said:

I have a friend who has a new cheap chain hanging on a finishing nail
in the garage. When he cleans the chain, he puts it on the finishing
nail on top of the new chain. Easy to see that the old chain has
"stretched". Very dramatic when you look at the total "stretch"
over a 4.5 foot chain. New chains are cheaper than chain checking tools.
$7.99 for a cheap chain at Nashbar compared to $9.95 for the Park
chain checking tool. And of course the truely frugal could just
have his replacement chain hanging in the garage and use it to check
for chain wear. And then install it when the old one is
"stretched". Then get a new replacement chain and repeat. No need
to squander money on a $0.39 wood ruler.

This is one of the more interesting and useful suggestions I've seen
lately. Think it may be catching?

Well, if you walk by the nail while wearing a Rayon shirt...

Bill "still slow afternoon" S.

Carl Fogel said:

Quoted message said:

Park CC-2 can hardly be inserted into a new Campagnolo C9 chain to
get a zero reading but reads 0.25% for a new SRAM PC59. Does the
average tech realise that? Do you call that consistent?

Quoted message said:

It sounds as if the tool is consistent, while the two brands of
chain are surprisingly different in how they would fit on a
sprocket.

As far as I have seen all these chains have 0.302" diameter rollers,
it's the width between side plates and overall width that is tuned to
how close the sprockets are in the gear cluster.

Quoted message said:

http://www.parktool.com/tools/CC_2BIG.shtml

Quoted message said:

Do these chains fit sprockets very differently? Are their rollers
different sizes?

All the ones I measured have 0.302" diameter rollers. That includes
ancient ones and current chains.

Jobst Brandt

In article <[email hidden]>,
"Jay Beattie" <[email hidden]> wrote:

[...]

Quoted message said:

Perching a ruling on a dirty chain is hardly accurate either -- I
wonder what the error rate is in the usual $.39 wood ruler. Not
that I am sold on the expensive Park tool, either -- although it
is kind of fun and looks more technical than a ruler (even my
steel ruler).

No need to wonder.
I compared a dial caliper (0.01" ticks) with an engineer's
scale. They agree to the limit of observation. I compared
the engineer's scale with two steel desk rulers, a wooden
desk ruler, a steel tape measure, a roofer's square, a
machinist's square, a draftsman's tee square, and a 4 foot
builders ruler.

The wooden desk ruler is off by 0.01" over 12".
The steel tape measure is off by 0.01" over 12".
The tee square is off by 0.02" over 12".
The 4 foot builders ruler is off by 0.03" over 12" all
along its length.
The other scales showed no deviation from the engineer's
scale.

[...]

--
Michael Press

Quoted message said:

On Mon, 15 Aug 2005 15:08:11 +0100, "Pete Biggs"
<[email hidden]> wrote:

[snip]

Quoted message said:

Park CC-2 can hardly be inserted into a new Campagnolo C9 chain to get a
zero reading but reads 0.25% for a new SRAM PC59. Does the average tech
realise that? Do you call that consistent?

~PB

Dear Pete,

It sounds as if the tool is consistent, while the two brands
of chain are surprisingly different in how they would fit on
a sprocket.

http://www.parktool.com/tools/CC_2BIG.shtml

Do these chains fit sprockets very differently? Are their
rollers different sizes?

Curiously,

Carl Fogel

1. sram come "pre-stretched". they're essentially an after-market chain
and as such more likely to be fitted onto previously used cogs so a
little over-spec makes them fit better.

2. a little over-spec means a little less time before replacement! good
for business.

Old Crow said:

1. sram come "pre-stretched". they're essentially an after-market
chain and as such more likely to be fitted onto previously used cogs
so a little over-spec makes them fit better.

I have a box full of SRAM chains and none show any visible deviation
from 1/2" pitch over their length, all pins lining up with 1/2" marks
on a steel rule. Where do you get this information and have you
verified it or is this just some more myth and lore?

Quoted message said:

2. a little over-spec means a little less time before replacement!
good for business.

That sounds like libel to me.

Jobst Brandt

Quoted message said:

Old Crow said:

1. sram come "pre-stretched". they're essentially an after-market
chain and as such more likely to be fitted onto previously used cogs
so a little over-spec makes them fit better.

I have a box full of SRAM chains and none show any visible deviation
from 1/2" pitch over their length, all pins lining up with 1/2" marks
on a steel rule. Where do you get this information and have you
verified it or is this just some more myth and lore?

Quoted message said:

2. a little over-spec means a little less time before replacement!
good for business.

That sounds like libel to me.

Jobst Brandt

Dear Pete, Jim, and Jobst,

I admit that I'm startled by the idea of a half-inch chain
that isn't half-inch.

But Pete is saying that the same Park chain measurement tool
will barely fit into a new Campy chain, but gives a 0.25%
wear indicator on a new SRAM chain:

"Park CC-2 can hardly be inserted into a new Campagnolo C9
chain to get a zero reading but reads 0.25% for a new SRAM
PC59."

http://www.parktool.com/tools/CC_2BIG.shtml

It may take a few new chains, a micrometer, a Park tool, and
so forth to clear this up.

If anyone has a new chain that's shorter than a new SRAM
chain, even by just a thousandth of an inch per link,
hanging the new chains (110 links or so) from the same nail
against a wall should show a noticeable difference.

If it's a matter of new rollers being a tiny bit smaller,
that wouldn't affect the half-inch pitch, but it would
presumably make the chain fit a bit differently onto a
sprocket. Determining that would take a micrometer or some
manufacturer's detailed specifications.

Carl Fogel

On Mon, 15 Aug 2005 21:00:48 -0700, jim beam <[email hidden]>

Quoted message said:

1. sram come "pre-stretched".

You're kidding, right?

JT

****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************

Quoted message said:

I admit that I'm startled by the idea of a half-inch chain
that isn't half-inch.

But Pete is saying that the same Park chain measurement tool
will barely fit into a new Campy chain, but gives a 0.25%
wear indicator on a new SRAM chain:

"Park CC-2 can hardly be inserted into a new Campagnolo C9
chain to get a zero reading but reads 0.25% for a new SRAM
PC59."

http://www.parktool.com/tools/CC_2BIG.shtml

It may take a few new chains, a micrometer, a Park tool, and
so forth to clear this up.

That would be good to do. Note that I'm not the only one to notice the
difference. There have been questions here before from posters who
couldn't figure out how to use their CC-2... because it can only be
/forced/ into a new Campag C9 chain. Park says "play" varies between
different makes of chain.

Quoted message said:

If anyone has a new chain that's shorter than a new SRAM
chain, even by just a thousandth of an inch per link,
hanging the new chains (110 links or so) from the same nail
against a wall should show a noticeable difference.

If it's a matter of new rollers being a tiny bit smaller,
that wouldn't affect the half-inch pitch, but it would
presumably make the chain fit a bit differently onto a
sprocket. Determining that would take a micrometer or some
manufacturer's detailed specifications.

Ditto. Cheap caliper + average eyeballs + cheap brain leaves me unable to
measure to more precision than 0.1mm or so.

~PB