Chain wear measurement

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".

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...

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

Richard McClary writes:

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".

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...

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

wrote:
Richard McClary writes:


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".


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...


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:

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.

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

wrote:
anonymous sniped:


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.


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.


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 wrote:
"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 wrote:
Leo Lichtman wrote:
"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

"Pete Biggs"
wrote in message ...
jim beam wrote:
Leo Lichtman wrote:
"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?

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).

Getting back to Jim Beams comment, why does roller wear not
count, but pin and bushing wear does? The rings haning on nails
analogy does not work for me, since some rings may be worn more
than others -- and in my case, even broken. -- Jay Beattie.

"Jay Beattie" wrote: (clip) The rings haning on nails analogy does not
work for me, since some rings may be worn more than others -- and in my
case, even broken.
^^^^^^^^^^^^^^^^
If some of the rollers are broken, the measurement of wear is irrelevant, or
moot, or academic. Throw the chain away. ;-)