Spoke Breakage Question

Arthur Shapiro said:

I'm breaking 2 - 3 spokes per year on the non-driven side of my rear (Campy 10
speed 3x to an Ambrosia Excellence.) Saturday was typical - powering into a
turn with the bike consequently leaning to one side, and PING. I'm using DT
15/16 on the left and 14/15 on the right. So in my case we're talking a
failure every 2-3K miles.

Where are they breaking, at the elbow? I use similar spoking on my main
bike (DT 15 straight gauge on the right, and 15/16 on the left). This
is on a Shimano 9-speed 36 spoke hub. I can't recall _ever_ breaking a
left side rear spoke in 30+ years of riding

Are your left side spokes tight enough that they don't need periodic
re-tightening? Using thinner spokes on the left (as you are doing)
should help prevent them from going slack.

Have you had any right side spoke failures? Have you stress relieved
the spokes?

This is very puzzling. Possibly a bad batch of spokes?

Art Harris

Quoted message said:

I'm breaking 2 - 3 spokes per year on the non-driven side of my rear (Campy
10
speed 3x to an Ambrosia Excellence.) Saturday was typical - powering into a
turn with the bike consequently leaning to one side, and PING. I'm using DT
15/16 on the left and 14/15 on the right. So in my case we're talking a
failure every 2-3K miles.

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side
quite
tight - no, I don't own a tensionometer - and obviously the left side spokes
are under considerably less tension.

Do other folks have this same issue? I'm reluctant to deliberately underdish
the wheel, but that's one obvious action that could be taken. A broken spoke
on the left isn't a particularly big deal in that the wheel doesn't go
grossly
out of true, but one shouldn't have to worry about it in the first place.

Art

This is a small nit to pick, Art, but both sides of the hub are driven,
because the hub shell is sufficiently strong torsionally.

Better to say "drive side", or better yet, "right side".

--
Ted Bennett

In article said:

Where are they breaking, at the elbow

Correct.

Quoted message said:

Are your left side spokes tight enough that they don't need periodic
re-tightening? Using thinner spokes on the left (as you are doing)
should help prevent them from going slack.

They don't need re-tightening aside from the usual periodic touchup of the
wheel trueness at months intervals. And yes, that's why I went thinner on the
left.

I originally built the wheel with DT Revolutions on the Velocity rim that I
still use up front, but couldn't keep it in true. Think they're too light for
me - I weigh about 160. That's when I went to the heavier spokes and rim.

Quoted message said:

Have you had any right side spoke failures? Have you stress relieved
the spokes?

Don't recall ever breaking a right sider, although I can't swear to that.
Certainly it would be an extreme aberration. I've done my best to
stress-relieve; I've built literally many hundreds of wheels and seem to have
the requisite techniques down fairly well.

Quoted message said:

This is very puzzling. Possibly a bad batch of spokes?

Agree! I normally purchase 1 or 2 spokes when I need them, so the "bad batch"
theory probably doesn't fly. And we wouldn't expect that of DT, anyway.

Ted: point well taken! I was just being conversationally informal.

Art

On Mon, 07 Aug 2006 18:38:09 GMT, Ted Bennett
<[email hidden]> wrote:

[snip]

Quoted message said:

Quoted message said:

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side
quite
tight - no, I don't own a tensionometer - and obviously the left side spokes
are under considerably less tension.

[snip]

Quoted message said:

Quoted message said:

Art

This is a small nit to pick, Art, but both sides of the hub are driven,
because the hub shell is sufficiently strong torsionally.

Better to say "drive side", or better yet, "right side".

Dear Ted,

Better to say drive-side and non-drive-side, since there are left-hand
drive bikes:

http://www.bmx-test.com/cgi-bin/reviews.cgi?review_id=745

So, naturalists observe, a flea
Has smaller fleas that on him prey;
And these have smaller still to bite ’em;
And so proceed ad infinitum.

(In my day, "flea" rhymed with "prey." Alas, the unmourned, silent,
terminal -a.)

Cheers,

J. Swift

On Mon, 07 Aug 2006 18:57:40 GMT, [email hidden] (Arthur

Shapiro) said:

In article said:

Where are they breaking, at the elbow

Correct.

Quoted message said:

Are your left side spokes tight enough that they don't need periodic
re-tightening? Using thinner spokes on the left (as you are doing)
should help prevent them from going slack.

They don't need re-tightening aside from the usual periodic touchup of the
wheel trueness at months intervals. And yes, that's why I went thinner on the
left.

I originally built the wheel with DT Revolutions on the Velocity rim that I
still use up front, but couldn't keep it in true. Think they're too light for
me - I weigh about 160. That's when I went to the heavier spokes and rim.

Quoted message said:

Have you had any right side spoke failures? Have you stress relieved
the spokes?

Don't recall ever breaking a right sider, although I can't swear to that.
Certainly it would be an extreme aberration. I've done my best to
stress-relieve; I've built literally many hundreds of wheels and seem to have
the requisite techniques down fairly well.

Quoted message said:

This is very puzzling. Possibly a bad batch of spokes?

Agree! I normally purchase 1 or 2 spokes when I need them, so the "bad batch"
theory probably doesn't fly. And we wouldn't expect that of DT, anyway.

Ted: point well taken! I was just being conversationally informal.

Art

Dear Art S. (I think),

Usually, the right-hand drive-side spokes fail sooner, partly because
they're under more tension and partly because they're more prone to
damage (that pesky chain).

But you're using "15/16 on the left and 14/15 on the right."

All things being equal (debatable), the thinner 15 gauge elbows on the
left will fail sooner than the thicker 14 gauge elbows on the right.

If you've built hundreds of wheels, a $60 Park tension gauge might be
worth buying to eliminate any questions about the actual tension on
your 15/16 left and 14/15 right wheel.

Hope I got my Arthurs right.

Cheers,

Carl Fogel

Arthur Shapiro said:

Art Harris said:

Where are they breaking, at the elbow

Correct.

Quoted message said:

Are your left side spokes tight enough that they don't need periodic
re-tightening? Using thinner spokes on the left (as you are doing)
should help prevent them from going slack.

They don't need re-tightening aside from the usual periodic touchup of the
wheel trueness at months intervals. And yes, that's why I went thinner on the
left.

I originally built the wheel with DT Revolutions on the Velocity rim that I
still use up front, but couldn't keep it in true. Think they're too light for
me - I weigh about 160. That's when I went to the heavier spokes and rim.

Quoted message said:

Have you had any right side spoke failures? Have you stress relieved
the spokes?

Don't recall ever breaking a right sider, although I can't swear to that.
Certainly it would be an extreme aberration. I've done my best to
stress-relieve; I've built literally many hundreds of wheels and seem to have
the requisite techniques down fairly well.

Quoted message said:

This is very puzzling. Possibly a bad batch of spokes?

Agree! I normally purchase 1 or 2 spokes when I need them, so the "bad batch"
theory probably doesn't fly. And we wouldn't expect that of DT, anyway.

Before giving up, I'd suggest finding some way to check the overall
tension to see if more can reasonably be added. Sounds like a problem I
had, using Revolutions (thinner on the non-drive-side as you did).
Increasing the tension seems to have solved the problem for me, though
my breakage was far less (one non-drive-side spoke every couple of
years), so it'll be a while before I'm sure.

For more details, here's a prior post on these wheels:
http://groups.google.com/group/rec.bicycles.tech/browse_thread/thread/7a0341592726cffd/628433195b878d3c?lnk=st&q=&rnum=1&hl=en#628433195b878d3c

Mark J.

[email hidden] wrote, in part:

Quoted message said:

If you've built hundreds of wheels, a $60 Park tension gauge might be
worth buying ....

Even if you haven't built hundreds......

D'ohBoy, who builds or rebuilds a set per year and is dang glad he's
got one.

Mark said:

Before giving up, I'd suggest finding some way to check the overall
tension to see if more can reasonably be added. Sounds like a problem I
had, using Revolutions (thinner on the non-drive-side as you did).
Increasing the tension seems to have solved the problem for me, though
my breakage was far less (one non-drive-side spoke every couple of
years), so it'll be a while before I'm sure.

For more details, here's a prior post on these wheels:
http://groups.google.com/group/rec.bicycles.tech/browse_thread/thread/7a0341592726cffd/628433195b878d3c?lnk=st&q=&rnum=1&hl=en#628433195b878d3c

Mark J.

Dear Mark,

Rumor has it that Sheldon Brown sells secret high-tech devices that
let even the most clueless wheel builder easily check the overall
tension:

http://www.sheldonbrown.com/harris/tools/wheel.html

I long to own the DT dial-gauge tension gauge, but even my usual
excuse "I'm a wealthy American" trails off at the $400 price tag. The
Park tension gauge works fine.

Rumor also has it that these secret tools known only to the ancients
can be obtained even more cheaply:

http://froogle.google.com/froogle?q=park+tension+gauge&hl=en&btnG=Search+Froogle

Cheers,

Carl Fogel

carlfogel said:

Usually, the right-hand drive-side spokes fail sooner, partly because
they're under more tension and partly because they're more prone to
damage (that pesky chain).

This is certainly not my experience. Most of the broken spokes I have
seen, on anyone's bike, have been on the left side. A few on the right,
but as you suggest those were mostly due to damage from a chain.

Quoted message said:

But you're using "15/16 on the left and 14/15 on the right."

All things being equal (debatable), the thinner 15 gauge elbows on the
left will fail sooner than the thicker 14 gauge elbows on the right.

All is not equal, and that is beyond debate. The left-side spokes will be
more likely to fail from fatigue, but that is because they are more
likely to be completely de-tensioned, not because they are thinner.

--

David L. Johnson

__o | "A foolish consistency is the hobgoblin of little minds, adored
_`\(,_ | by little statesmen and philosophers and divines." --Ralph Waldo
(_)/ (_) | Emerson

Arthur Shapiro said:

I'm breaking 2 - 3 spokes per year on the non-driven side of my rear (Campy 10
speed 3x to an Ambrosia Excellence.) Saturday was typical - powering into a
turn with the bike consequently leaning to one side, and PING. I'm using DT
15/16 on the left and 14/15 on the right. So in my case we're talking a
failure every 2-3K miles.

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side quite
tight - no, I don't own a tensionometer - and obviously the left side spokes
are under considerably less tension.

You break these at the head, right? That is a fatigue issue, and can only
be improved by increasing the tension.

Quoted message said:

Do other folks have this same issue?

Not that much. I had one spoke go on a 5+ year-old wheel, with possibly
5000-10000 miles on it (not sure of the mileage, since I have two rear
wheels for that bike). I took that as a sign that the wheel was not
adequately tensioned.

I'm reluctant to deliberately

Quoted message said:

underdish the wheel, but that's one obvious action that could be taken.

Don't do that. The bike will not track properly if you do, and the wheel
won't sit properly in the frame. I recommend an off-center rim, which
lessens the extremity of the dish without ruining your handling. Yes,
modern rear wheels do have an extreme amount of dish, but you can still
build a reliable wheel.

--

David L. Johnson

__o | The motor car reflects our standard of living and gauges the
_`\(,_ | speed of our present life. It long ago ran down Simple Living,
(_)/ (_) | and never halted to inquire about the prostrate figure which
fell as its victim. -- Warren G. Harding

David L. Johnson said:

carlfogel said:

Usually, the right-hand drive-side spokes fail sooner, partly because
they're under more tension and partly because they're more prone to
damage (that pesky chain).

This is certainly not my experience.

[snip]

Dear David,

It's certainly mine.

Cheers,

Carl Fogel

Arthur Shapiro said:

I'm breaking 2 - 3 spokes per year on the non-driven side of my rear (Campy 10
speed 3x to an Ambrosia Excellence.) Saturday was typical - powering into a
turn with the bike consequently leaning to one side, and PING. I'm using DT
15/16 on the left and 14/15 on the right. So in my case we're talking a
failure every 2-3K miles.

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side quite
tight - no, I don't own a tensionometer - and obviously the left side spokes
are under considerably less tension.

Do other folks have this same issue? I'm reluctant to deliberately underdish
the wheel, but that's one obvious action that could be taken. A broken spoke
on the left isn't a particularly big deal in that the wheel doesn't go grossly
out of true, but one shouldn't have to worry about it in the first place.

Art

Some recommend radial lacing on the NDS as a solution to this problem
(NDS spoke breakage).

<ducks and covers>

D'ohBoy, whose radially laced wheels are doing just fine.

Quoted message said:

On Mon, 07 Aug 2006 12:25:51 -0700, Mark

Quoted message said:

Before giving up, I'd suggest finding some way to check the overall
tension to see if more can reasonably be added. Sounds like a problem I
had, using Revolutions (thinner on the non-drive-side as you did).
Increasing the tension seems to have solved the problem for me, though
my breakage was far less (one non-drive-side spoke every couple of
years), so it'll be a while before I'm sure.

For more details, here's a prior post on these wheels:
http://groups.google.com/group/rec.bicycles.tech/browse_thread/thread/7a0341592726cffd/628433195b878d3c?lnk=st&q=&rnum=1&hl=en#628433195b878d3c

Rumor has it that Sheldon Brown sells secret high-tech devices that
let even the most clueless wheel builder easily check the overall
tension:

http://www.sheldonbrown.com/harris/tools/wheel.html

I long to own the DT dial-gauge tension gauge, but even my usual
excuse "I'm a wealthy American" trails off at the $400 price tag. The
Park tension gauge works fine.

Rumor also has it that these secret tools known only to the ancients
can be obtained even more cheaply:

http://froogle.google.com/froogle?q=park+tension+gauge&hl=en&btnG=Search+Froogle

Carl, allow me to rephrase my advice to Arthur:

Before giving up, I'd suggest finding some way to borrow/use a tension
gauge to check the overall tension to see if more can reasonably be
added. Purchase one if needed, but a visit to your friendly LBS may
make that unnecessary, especially if you are a valued regular customer.

For making sure that tension is *even* in all the spokes on one side of
a wheel, a gauge is not necessary unless you are tone deaf (as many
otherwise normal people are).

Mark "pluck-ping" J.

David L. Johnson said:

carlfogel said:

Usually, the right-hand drive-side spokes fail sooner, partly because
they're under more tension and partly because they're more prone to
damage (that pesky chain).

This is certainly not my experience. Most of the broken spokes I have
seen, on anyone's bike, have been on the left side. A few on the right,
but as you suggest those were mostly due to damage from a chain.

Quoted message said:

But you're using "15/16 on the left and 14/15 on the right."

All things being equal (debatable), the thinner 15 gauge elbows on the
left will fail sooner than the thicker 14 gauge elbows on the right.

All is not equal, and that is beyond debate. The left-side spokes will be
more likely to fail from fatigue, but that is because they are more
likely to be completely de-tensioned, not because they are thinner.

David, I'm having some sort of anti-deja-vu over this.

My experience in the last 10-15 years agrees with yours, yet going back
further (25-30 years) the common wisdom (especially on camping tours)
was what Carl cited.

Have things changed? I wouldn't think freewheel-vs-freehub would change
the *side* on which the spokes commonly broke. Maybe it's a
carefully-hand-built vs crudely-machine-built thing, since my (few)
left-side failures have been low tension issues on handbuilts, while the
long-ago right-side failures were mostly on factory wheels.

Any ideas? Anybody?

Mark J.

Arthur Shapiro said:

I'm breaking 2 - 3 spokes per year on the non-driven side of my rear (Campy 10
speed 3x to an Ambrosia Excellence.) Saturday was typical - powering into a
turn with the bike consequently leaning to one side, and PING. I'm using DT
15/16 on the left and 14/15 on the right. So in my case we're talking a
failure every 2-3K miles.

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side quite
tight - no, I don't own a tensionometer - and obviously the left side spokes
are under considerably less tension.

Do other folks have this same issue? I'm reluctant to deliberately underdish
the wheel, but that's one obvious action that could be taken. A broken spoke
on the left isn't a particularly big deal in that the wheel doesn't go grossly
out of true, but one shouldn't have to worry about it in the first place.

Art

Where on the spoke is the break happening?

Quoted message said:

On Mon, 07 Aug 2006 18:38:09 GMT, Ted Bennett wrote:

[snip]

Quoted message said:

Quoted message said:

I'm starting to think this is an almost unavoidable issue due to the
substantial dish on these huge modern clusters. I have the driven side
quite
tight - no, I don't own a tensionometer - and obviously the left side
spokes
are under considerably less tension.

[snip]

Quoted message said:

Quoted message said:

Art

This is a small nit to pick, Art, but both sides of the hub are driven,
because the hub shell is sufficiently strong torsionally.

Better to say "drive side", or better yet, "right side".

Dear Ted,

Better to say drive-side and non-drive-side, since there are left-hand
drive bikes:

http://www.bmx-test.com/cgi-bin/reviews.cgi?review_id=745

So, naturalists observe, a flea
Has smaller fleas that on him prey;
And these have smaller still to bite ’em;
And so proceed ad infinitum.

(In my day, "flea" rhymed with "prey." Alas, the unmourned, silent,
terminal -a.)

Cheers,

J. Swift

Dear Mr. Swift,

Somehow I know you would be sending that message as soon as I hit the
send key.

In the interest of of clarity and brevity, I omitted the vast fleets of
left-side drive bikes and two-wheel drive bikes.

Now, where is that flea powder. . .

--
Ted Bennett

Mark said:

David L. Johnson said:

carlfogel said:

Usually, the right-hand drive-side spokes fail sooner, partly because
they're under more tension and partly because they're more prone to
damage (that pesky chain).

This is certainly not my experience. Most of the broken spokes I have
seen, on anyone's bike, have been on the left side. A few on the right,
but as you suggest those were mostly due to damage from a chain.

Quoted message said:

But you're using "15/16 on the left and 14/15 on the right."

All things being equal (debatable), the thinner 15 gauge elbows on the
left will fail sooner than the thicker 14 gauge elbows on the right.

All is not equal, and that is beyond debate. The left-side spokes will be
more likely to fail from fatigue, but that is because they are more
likely to be completely de-tensioned, not because they are thinner.

David, I'm having some sort of anti-deja-vu over this.

My experience in the last 10-15 years agrees with yours, yet going back
further (25-30 years) the common wisdom (especially on camping tours)
was what Carl cited.

Have things changed? I wouldn't think freewheel-vs-freehub would change
the *side* on which the spokes commonly broke. Maybe it's a
carefully-hand-built vs crudely-machine-built thing, since my (few)
left-side failures have been low tension issues on handbuilts, while the
long-ago right-side failures were mostly on factory wheels.

Any ideas? Anybody?

Back in the time of 5/6 SP spacing, when there was less "dish" on the
rear wheel, tension was more "balanced" L to R. The machine built
wheels of that time were woefully under tensioned and, IMO, were likely
to break spokes on either side.

With 8/9/10 SP spacing, there is a large imbalance of tension L to R.
With proper tension on the right, the left may still be undertensioned
and prone to fatigue failure. But, IMO, a 8/9/10 SP wheel that breaks
*right* side spokes is just very poorly built.

In article <[email hidden]>,

(Arthur Shapiro) said:

They don't need re-tightening aside from the usual periodic touchup of the
wheel trueness at months intervals. And yes, that's why I went thinner on the
left.

Most of us here who build our own wheels do not
periodically touch up the wheels. We build them and ride
them. You need to go back to the very beginning and learn
how to build wheels. I will mention a few, but not all
elements to wheel building. Lubricate threads and nipple
seats, stress relieve, balance tension, fully tension the
spokes, eliminate spoke wind-up.

--
Michael Press

Arthur Shapiro said:

In article said:

Where are they breaking, at the elbow

Correct.

Quoted message said:

Are your left side spokes tight enough that they don't need periodic
re-tightening? Using thinner spokes on the left (as you are doing)
should help prevent them from going slack.

They don't need re-tightening aside from the usual periodic touchup of the
wheel trueness at months intervals.

right there is your problem. sounds like inadequate spoke tension.
invest $60 in that tensiometer and make sure the drive side spokes are
at rim manufacturer spec. the non-drive side spokes will be at ~50% of
that on a campy hub. make sure the wheel is properly "stress relieved"
multiple times during the truing process and keep doing it until there
is no more deviation each time you stress it. maybe consider thread
lock too.

Quoted message said:

And yes, that's why I went thinner on the
left.

I originally built the wheel with DT Revolutions on the Velocity rim that I
still use up front, but couldn't keep it in true. Think they're too light for
me - I weigh about 160.

160 is not heavy! inadequate spoke tension and insufficient "stress
relief", more correctly described as bedding the spokes in. if tension
is inadequate, spoke nipples unscrew upsetting the true and ultimately
reaching a point where the bending load cycle on the spoke elbow is
excessive, hence fatigue failure. if bedding in is insufficient, the
rim/hub interface with the spoke continues to deform a little in
service, and a similar de-tensioning process occurs with the same
result. again, keep bedding in until the wheel stays true, and consider
threadlock is the problem recurs.

Quoted message said:

That's when I went to the heavier spokes and rim.

Quoted message said:

Have you had any right side spoke failures? Have you stress relieved
the spokes?

Don't recall ever breaking a right sider, although I can't swear to that.
Certainly it would be an extreme aberration. I've done my best to
stress-relieve; I've built literally many hundreds of wheels and seem to have
the requisite techniques down fairly well.

Quoted message said:

This is very puzzling. Possibly a bad batch of spokes?

Agree! I normally purchase 1 or 2 spokes when I need them, so the "bad batch"
theory probably doesn't fly. And we wouldn't expect that of DT, anyway.

Ted: point well taken! I was just being conversationally informal.

Art