Too-Wide Chain: More Likely To Break?

I just parted the chain on my singlespeed - really standing on it going uphill.

In retrospect, I'm wondering if it's being the widest chain available
(operatively, the cheapest....) might have had something to do with the break.

I can visualize the cog/chainwheel teeth seating on one side or the other and
creating a force that wants to peel the plates off the pins.

Replaced it with a properly sized one (3/8?)...but also have a wide chain on my
FS/Rohloff bike and am wondering if I should do a premptive replacement.
--
PeteCresswell

(Pete Cresswell) wrote:

I just parted the chain on my singlespeed - really standing on it going uphill.

In retrospect, I'm wondering if it's being the widest chain available
(operatively, the cheapest....) might have had something to do with the break.

I can visualize the cog/chainwheel teeth seating on one side or the other and
creating a force that wants to peel the plates off the pins.

Replaced it with a properly sized one (3/8?)...but also have a wide chain on my
FS/Rohloff bike and am wondering if I should do a premptive replacement.

This may be completely irrelevant, but Taya's own figures show that
their 1/4" chain is a fair bit weaker than their 3/16".

"(Pete Cresswell)" wrote in message . ..
I just parted the chain on my singlespeed - really standing on it going uphill.

In retrospect, I'm wondering if it's being the widest chain available
(operatively, the cheapest....) might have had something to do with the break.

I can visualize the cog/chainwheel teeth seating on one side or the other and
creating a force that wants to peel the plates off the pins.

Replaced it with a properly sized one (3/8?)...but also have a wide chain on my
FS/Rohloff bike and am wondering if I should do a premptive replacement.

Dear Pete,

While chain sizes are a mystery to me,
it sounds as if you put the wrong size
nut on a bolt and it stripped. It also
sounds as if you've figured it out.

That is, if a narrower chain fits your
gears "properly," then the wider chain
must have been the wrong size.

When in doubt, use the right parts.

Carl Fogel

(Carl Fogel) wrote:

While chain sizes are a mystery to me,
it sounds as if you put the wrong size
nut on a bolt and it stripped. It also
sounds as if you've figured it out.

That is, if a narrower chain fits your
gears "properly," then the wider chain
must have been the wrong size.

When in doubt, use the right parts.

1/8" (single speed) chain and 3/32" (derailleur) chains have always
been interchangeable on 3/32" single-speed drivetrains. That is the
the reason 3/32" single-speed drivetrain parts exist-- to enable the
use of either width of chain.

Pete Cresswell's chain breakage is unrelated to the width of the chain
in question. However, it's not difficult to imagine that a chain that
retails for $5 and is overwhelmingly likely to find use on a kid's
bike might not be made to the same standard of materials or tolerances
as a $20 derailleur bike chain.

Typical features of quality 3/32" chain not usually found in 1/8"
chain include beveled sideplates, "bushingless" construction, and
riveted pins. The "master links" furnished with 1/8" chain are there
for convenience, but those of newer 3/32" chain are supplied to
replace the sideplates damaged by pushing riveted pins through them.

Chalo Colina

(Chalo) wrote in message . com...
(Carl Fogel) wrote:

While chain sizes are a mystery to me,
it sounds as if you put the wrong size
nut on a bolt and it stripped. It also
sounds as if you've figured it out.

That is, if a narrower chain fits your
gears "properly," then the wider chain
must have been the wrong size.

When in doubt, use the right parts.

1/8" (single speed) chain and 3/32" (derailleur) chains have always
been interchangeable on 3/32" single-speed drivetrains. That is the
the reason 3/32" single-speed drivetrain parts exist-- to enable the
use of either width of chain.

Pete Cresswell's chain breakage is unrelated to the width of the chain
in question. However, it's not difficult to imagine that a chain that
retails for $5 and is overwhelmingly likely to find use on a kid's
bike might not be made to the same standard of materials or tolerances
as a $20 derailleur bike chain.

Typical features of quality 3/32" chain not usually found in 1/8"
chain include beveled sideplates, "bushingless" construction, and
riveted pins. The "master links" furnished with 1/8" chain are there
for convenience, but those of newer 3/32" chain are supplied to
replace the sideplates damaged by pushing riveted pins through them.

Chalo Colina

Dear Chalo,

I suspect that I stand corrected, but I'm
sure that I'm confused.

Do the gears differ in width? That is, are
there thin gears for 3/32 and wide gears for
1/8 chain?

If so, shouldn't a 33% wider 4/32 chain wear
or even break differently on a gear intended
for 3/32 chain?

While 1/32nd of an inch might be small in terms
of lengthwise chain play and tension, it seems
rather significant when it's a quarter or a
third of the sideways dimension. Why wouldn't
it cock a bit sideways, strain, and break as
Pete speculated?

Or is all this like 2x4 lumber, which isn't
2 inches by 4 inches, or .50 caliber Browning,
whose slug is wider than 0.500?

Fascinated as usual,

Carl Fogel

(Carl Fogel) wrote:

Do the gears differ in width? That is, are
there thin gears for 3/32 and wide gears for
1/8 chain?

Yes.

Sprockets for 3/32" chain are about 2mm wide or .080", and those for
1/8" chain are about 3mm wide, or .120" (Even though the chains will
accomodate their rated tooth widths of .09375" and .125" respectively)

If so, shouldn't a 33% wider 4/32 chain wear
or even break differently on a gear intended
for 3/32 chain?

Maybe in principle it should, but in practice there does not seem to
be a problem. Single-speed components have been made in 3/32" tooth
widths in order to enable the use of commonly available 3/32" chain as
well as the traditional 1/8" kind.

While 1/32nd of an inch might be small in terms
of lengthwise chain play and tension, it seems
rather significant when it's a quarter or a
third of the sideways dimension. Why wouldn't
it cock a bit sideways, strain, and break as
Pete speculated?

Because it's still being pulled by teeth whose faces are nominally
square to the chainline, engaging rollers that are cylindrical inside
and out. If the pull on the chain is in the same plane as both
sprockets, then there's no "sideways" about it. The sprocket teeth
are significantly narrower than the chain's capacity, even when they
are the same nominal size. If they needed to fill the chain's width,
they would be wider.

Chalo Colina

(Chalo) wrote in message . com...
(Carl Fogel) wrote:

Do the gears differ in width? That is, are
there thin gears for 3/32 and wide gears for
1/8 chain?

Yes.

Sprockets for 3/32" chain are about 2mm wide or .080", and those for
1/8" chain are about 3mm wide, or .120" (Even though the chains will
accomodate their rated tooth widths of .09375" and .125" respectively)

If so, shouldn't a 33% wider 4/32 chain wear
or even break differently on a gear intended
for 3/32 chain?

Maybe in principle it should, but in practice there does not seem to
be a problem. Single-speed components have been made in 3/32" tooth
widths in order to enable the use of commonly available 3/32" chain as
well as the traditional 1/8" kind.

While 1/32nd of an inch might be small in terms
of lengthwise chain play and tension, it seems
rather significant when it's a quarter or a
third of the sideways dimension. Why wouldn't
it cock a bit sideways, strain, and break as
Pete speculated?

Because it's still being pulled by teeth whose faces are nominally
square to the chainline, engaging rollers that are cylindrical inside
and out. If the pull on the chain is in the same plane as both
sprockets, then there's no "sideways" about it. The sprocket teeth
are significantly narrower than the chain's capacity, even when they
are the same nominal size. If they needed to fill the chain's width,
they would be wider.

Chalo Colina

Dear Chalo,

Thanks for the detailed numbers. As usual, your
patient mechanical explanation makes sense, but
that only works with sensible people.

I'm stuck on the chain needing to pull in the
same plane on both sprockets. While I'm sure
that Pete's sprockets are flawlessly in plane,
would the kind of bad chain-line sometimes
mentioned in this newsgroup be enough to
affect matters?

That is, if the front sprocket was nicely
perpendicular to the frame like the rear
axle, but sticking out as far as careless
folk sometimes assemble a bicycle, would
that small a difference cock the chain
sideways enough to lead to trouble?
__
_____------------

(I have no idea how far chain-lines get
out-of-plane, so I'm being lazy and
asking someone with experience. My guess
is that your answer will be no, even
a typical bad chain-line isn't enough
to damage a too-wide chain, but I'd
rather know than guess.)

Thanks again,

Carl Fogel

(Carl Fogel) wrote in message . com...
(Chalo) wrote in message . com...
(Carl Fogel) wrote:

Do the gears differ in width? That is, are
there thin gears for 3/32 and wide gears for
1/8 chain?

Yes.

Sprockets for 3/32" chain are about 2mm wide or .080", and those for
1/8" chain are about 3mm wide, or .120" (Even though the chains will
accomodate their rated tooth widths of .09375" and .125" respectively)

If so, shouldn't a 33% wider 4/32 chain wear
or even break differently on a gear intended
for 3/32 chain?

Maybe in principle it should, but in practice there does not seem to
be a problem. Single-speed components have been made in 3/32" tooth
widths in order to enable the use of commonly available 3/32" chain as
well as the traditional 1/8" kind.

While 1/32nd of an inch might be small in terms
of lengthwise chain play and tension, it seems
rather significant when it's a quarter or a
third of the sideways dimension. Why wouldn't
it cock a bit sideways, strain, and break as
Pete speculated?

Because it's still being pulled by teeth whose faces are nominally
square to the chainline, engaging rollers that are cylindrical inside
and out. If the pull on the chain is in the same plane as both
sprockets, then there's no "sideways" about it. The sprocket teeth
are significantly narrower than the chain's capacity, even when they
are the same nominal size. If they needed to fill the chain's width,
they would be wider.

Chalo Colina

Dear Chalo,

Thanks for the detailed numbers. As usual, your
patient mechanical explanation makes sense, but
that only works with sensible people.

I'm stuck on the chain needing to pull in the
same plane on both sprockets. While I'm sure
that Pete's sprockets are flawlessly in plane,
would the kind of bad chain-line sometimes
mentioned in this newsgroup be enough to
affect matters?

That is, if the front sprocket was nicely
perpendicular to the frame like the rear
axle, but sticking out as far as careless
folk sometimes assemble a bicycle, would
that small a difference cock the chain
sideways enough to lead to trouble?
__
_____------------

(I have no idea how far chain-lines get
out-of-plane, so I'm being lazy and
asking someone with experience. My guess
is that your answer will be no, even
a typical bad chain-line isn't enough
to damage a too-wide chain, but I'd
rather know than guess.)

Thanks again,

Carl Fogel

People put extreme angles on their chains all the time, with no
immediate ill consequence. Picture small ring/small cog or big
ring/big cog gear combinations. The derailleur takes care of the
chain alignment on the bottom of the cog, but where the chain comes
off the top of the cog (where the real stress is) the angle can be
quite severe.

The OPs chain broke because he used a cheap chain, not because it was
too wide.

(Scott Hendricks) wrote in message om...

[snip]

People put extreme angles on their chains all the time, with no
immediate ill consequence. Picture small ring/small cog or big
ring/big cog gear combinations. The derailleur takes care of the
chain alignment on the bottom of the cog, but where the chain comes
off the top of the cog (where the real stress is) the angle can be
quite severe.

The OPs chain broke because he used a cheap chain, not because it was
too wide.

Dear Scott,

Yes, derailleurs criss-cross chains at
angles without much trouble.

But I'm asking Chalo about too-wide
chains that normally run only in a
straight line on narrow gears and
what he thinks might happen with a
bad chain-line, where the wrong
bottom-bracket width constantly
mimics wicked cross-chaining.

I suspect that Chalo will reassure
me that the angle is too small to
affect even mis-matched chain rattling
on narrow gear-teeth, but I had to
ask, since Chalo had already mentioned
that theory and practice didn't seem
to agree.

Carl Fogel

(Carl Fogel) wrote:

(Chalo) wrote:

If the pull on the chain is in the same plane as both
sprockets, then there's no "sideways" about it. The sprocket teeth
are significantly narrower than the chain's capacity, even when they
are the same nominal size.

I'm stuck on the chain needing to pull in the
same plane on both sprockets. While I'm sure
that Pete's sprockets are flawlessly in plane,
would the kind of bad chain-line sometimes
mentioned in this newsgroup be enough to
affect matters?

Yes. Chain line is more important on a single-speed drivetrain than
on a derailleur drivetrain, because the sprockets are designed to
positively retain the chain and their design assumes decent alignment.

For small amounts of offset between parallel sprockets, a wider chain
is more forgiving simply because it is wider, and thus can run
perfectly straight between sprockets that fall to either side of its
internal clearance. However, the wider chain has longer pins and
wider bushings, and so puts up much more resistance than a narrow to
being deflected diagonally.

Go-kart enthusiasts (who use chain that is quite wide for its pitch)
cope with the occasional terrible sprocket alignment by using
so-called "space chain" composed of narrow inner links running on
wider outer links, which allows the chain to traverse some lateral
distance in a stairstep fashion.

When an industrial chain must take up a sizeable offset or angular
difference between sprockets, "curved type" chain in used. The
bushings in such a chain have a somewhat hourglass-shaped bore and the
clearance between inner and outer sideplates is increased to allow the
chain to describe a radius as small as 30 times its pitch length.

If you look at the pictures under "Chains: Old and New" on Sheldon
Brown's informative page http://sheldonbrown.com/chains.html , you can
see that the effective bushing area of a modern "bushingless"
derailleur-bike chain is even narrower than the narrow chain width
would require, and has some of the flaring hourglass-like
characteristic that typefies chains intended for misalignment.

So today's typical 3/32" chain will tolerate misalignment better than
old-style 1/8" chain, but not predominantly because it is narrower.
The #40 curved-type chain I have used in machinery is 1/2" pitch like
a bike chain, but fully twice as wide. It bends sideways more freely
than either kind of bike chain because it is internally configured to
do so. Likewise the design characteristics of "bushingless" bike
chain allow more sideways flexibility and tolerance of misalignment
than a traditional bike chain.

In a derailleur bike, poor chainline is a condition of normal
operation. But you don't have the choice of running oldfangled 1/8"
chain on a derailleur bike, so in that case you're limited to the
appropriate kind. (Especially now that traditional 3/32" chain with
bushings is on the way to extinction.)

Chalo