Spoke tension assessed by plucking like a string

Art who? said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

Quoted message said:

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the
tone produced by plucking spokes be used as a good monitor on the
condition of the wheel?

Quoted message said:

Any comments? I'm thinking of taking it back to the store and have
it checked out.

Since he let it out of the bag in that condition, I don't have much
faith in them fixing it. Yes once I have the wheel up to the tension
I want, I do all subsequent truing by finding which spokes are high or
low by tone.

I recently trued a wheel for a friend that was radially out by a few
mm and laterally had a wow or two. This wheel had some bad treatment
an had humps that mere spoke tensioning could not fix so I used my rim
curvature clamp After getting it radially true, I could take care of
the rest with manual rim bending and spoke tension.

These methods are explained in detail in "the Bicycle Wheel".

Jobst Brandt

Artoi <[email hidden]> wrote in news:artoi-383CB2.10525025092006@news-
server.bigpond.net.au:

Quoted message said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the tone
produced by plucking spokes be used as a good monitor on the condition
of the wheel?

Any comments? I'm thinking of taking it back to the store and have it
checked out.
--

For instructions on checking spoke tension by ear see:
http://www.bikexprt.com/bicycle/tension.htm

Rich

In article <[email hidden]>,

Quoted message said:

Art who? said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

Quoted message said:

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the
tone produced by plucking spokes be used as a good monitor on the
condition of the wheel?

Quoted message said:

Any comments? I'm thinking of taking it back to the store and have
it checked out.

Since he let it out of the bag in that condition, I don't have much
faith in them fixing it. Yes once I have the wheel up to the tension
I want, I do all subsequent truing by finding which spokes are high or
low by tone.

I recently trued a wheel for a friend that was radially out by a few
mm and laterally had a wow or two. This wheel had some bad treatment
an had humps that mere spoke tensioning could not fix so I used my rim
curvature clamp After getting it radially true, I could take care of
the rest with manual rim bending and spoke tension.

These methods are explained in detail in "the Bicycle Wheel".

Jobst Brandt

Good to know the above.

The wheel was a pre-fabricated model from a name brand and was new when
the LBS passed it to me. And before the long ride yesterday, I don't
recall the presence of that problem although I didn't check each spoke
out with as much care. Is it possible that the long ride loosened one or
two of the spokes? Would this be a known and expected issue? Or wheels
shouldn't really do this and I should start to suspect some fundamental
quality issues with the wheel?
--

In article <[email hidden]>,

Artoi said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

I use it all the time when building wheels. I designate a "master
spoke" and measure the tension of that one with a tensiometer, and then
use my ears to bring the tension up evenly, checking the master spoke's
tension once in a while with the tensiometer.

Quoted message said:

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the
tone produced by plucking spokes be used as a good monitor on the
condition of the wheel?

Any comments? I'm thinking of taking it back to the store and have it
checked out. --

Well, that the spoke has lost tension is one possibility. Make sure
there isn't some kind of cruft stuck in the spoke crossing closest to
the rim.

In article <[email hidden]>,

Artoi said:

The wheel was a pre-fabricated model from a name brand and was new when
the LBS passed it to me. And before the long ride yesterday, I don't
recall the presence of that problem although I didn't check each spoke
out with as much care. Is it possible that the long ride loosened one or
two of the spokes?

Yes.

Quoted message said:

Would this be a known and expected issue?

Known, yes. Expected, all too frequently.

Quoted message said:

Or wheels shouldn't really do this and I should start to suspect some
fundamental quality issues with the wheel?

Wheels really shouldn't do this. A common cause of spokes detensioning
is that the tension is too low to begin with, and the spoke nipple
unthreads as the spoke passes under the hub and is loaded by the weight
of the rider. The spoke goes slack, allowing vibrations to unscrew the
nipple a bit.

Artoi <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

The wheel was a pre-fabricated model from a name brand and was new
when the LBS passed it to me. And before the long ride yesterday, I
don't recall the presence of that problem although I didn't check each
spoke out with as much care. Is it possible that the long ride
loosened one or two of the spokes? Would this be a known and expected
issue? Or wheels shouldn't really do this and I should start to
suspect some fundamental quality issues with the wheel?
--

If the wheel was not fully tensioned, spokes will loosen. As the wheel
rotates under a load, the tension on spokes is continually loading and
unloading. If the spoke tension is not high enough, when the spokes
unload the nipples can slowly unscrew and loosen. (This can also lead to
spoke breakage at the bend where the spokes comes out of the hub.)

I had a machine built wheel I bought from a LBS that was not tensioned
properly, the spokes kept loosening. I eventially got tired of truing
this wheel on the bike and bought a truing stand. I retensioned and
trued the wheel and it has run true ever since since.

If you buy a machine built wheel from a LBS they may not check the
tension unless you ask to have it done; you will probably have to pay
extra for this service.

I also had a wheel that one single spoke kept continually loosening; the
problem turned out to be a nipple pulling through the rim wall under the
manufacturer decal. The failure of the rim was hidden until I got
suspicious enough to peel back the label. I ended up replacing the rim.

Richard B.

In article <[email hidden]>,

Tim McNamara said:

In article <[email hidden]>,

Artoi said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

I use it all the time when building wheels. I designate a "master
spoke" and measure the tension of that one with a tensiometer, and then
use my ears to bring the tension up evenly, checking the master spoke's
tension once in a while with the tensiometer.

Quoted message said:

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the
tone produced by plucking spokes be used as a good monitor on the
condition of the wheel?

Any comments? I'm thinking of taking it back to the store and have it
checked out. --

Well, that the spoke has lost tension is one possibility. Make sure
there isn't some kind of cruft stuck in the spoke crossing closest to
the rim.

Thanks for the advice. Although there's some crossing of the spokes in
the rear wheel, they don't actually come into contact. So the dullness
wasn't through interference.

So the obvious question here is, can one just touch up the tension at
home to equalize the tone? Or shouldn't one touch it except in a truing
stand? Of course, this is under the assumption that there's no flats or
other significant hardware issues with the wheel.

I note that the wheel came with a spoke adjuster.
--

In article <[email hidden]>,

Richard B said:

For instructions on checking spoke tension by ear see:
http://www.bikexprt.com/bicycle/tension.htm

Got it.
--

In article <[email hidden]>,

Tim McNamara said:

In article <[email hidden]>,

Artoi said:

The wheel was a pre-fabricated model from a name brand and was new when
the LBS passed it to me. And before the long ride yesterday, I don't
recall the presence of that problem although I didn't check each spoke
out with as much care. Is it possible that the long ride loosened one or
two of the spokes?

Yes.

Quoted message said:

Would this be a known and expected issue?

Known, yes. Expected, all too frequently.

Quoted message said:

Or wheels shouldn't really do this and I should start to suspect some
fundamental quality issues with the wheel?

Wheels really shouldn't do this. A common cause of spokes detensioning
is that the tension is too low to begin with, and the spoke nipple
unthreads as the spoke passes under the hub and is loaded by the weight
of the rider. The spoke goes slack, allowing vibrations to unscrew the
nipple a bit.

That all makes sense. I'll visit the LBS and see what they say and make
a decision on whether I should keep the wheel.
--

Artoi said:

In article <[email hidden]>,

Richard B said:

For instructions on checking spoke tension by ear see:
http://www.bikexprt.com/bicycle/tension.htm

Got it.

I use my Spokey as a pick.

http://www.wildside-online.co.uk/posit/shop/index.php?category=29&group=16

Ron

In article <[email hidden]>,

RonSonic said:

Artoi said:

In article <[email hidden]>,

Richard B said:

For instructions on checking spoke tension by ear see:
http://www.bikexprt.com/bicycle/tension.htm

Got it.

I use my Spokey as a pick.

http://www.wildside-online.co.uk/posit/shop/index.php?category=29&group=16

Do you touch up on the spoke tension without putting it on a truing
stand?
--

<[email hidden]> wrote in message
news:[email hidden]...
|
snip
|
| I recently trued a wheel for a friend that was radially out by a few
| mm and laterally had a wow or two. This wheel had some bad treatment
| an had humps that mere spoke tensioning could not fix so I used my rim
| curvature clamp After getting it radially true, I could take care of
| the rest with manual rim bending and spoke tension.
|
| These methods are explained in detail in "the Bicycle Wheel".
|
| Jobst Brandt

What is a "rim curvature clamp"?

Jean

In article <[email hidden]>,

Artoi said:

Thanks for the advice. Although there's some crossing of the spokes
in the rear wheel, they don't actually come into contact. So the
dullness wasn't through interference.

The spokes don't touch where they cross? Odd. What make and model
wheel is this?

Quoted message said:

So the obvious question here is, can one just touch up the tension at
home to equalize the tone? Or shouldn't one touch it except in a
truing stand? Of course, this is under the assumption that there's no
flats or other significant hardware issues with the wheel.

You can use the bike itself as a truing stand, although that's going to
be easier for lateral truing than for radial truing. In terms of
riding, though, it's more important that the wheel be true and round
than for every spoke to have identical tension. If this is a spoke at
the rim seam, for example, the tension may be lower or higher because
that part of the rim is stiffer than the rest of the rim.

In fact, I don't think that's been mentioned. If the nipple for this
spoke is immediately adjacent to the rim seam, I wouldn't worry about it
sounding different than the rest. The spokes on either side of the seam
often have different tension than the rest.

Tim McNamara said:

In article <[email hidden]>,

Artoi said:

Is the tone produced by plucking a spoke an important gauge of even
tension on the wheel?

I use it all the time when building wheels. I designate a "master
spoke" and measure the tension of that one with a tensiometer, and then
use my ears to bring the tension up evenly, checking the master spoke's
tension once in a while with the tensiometer.

Quoted message said:

After a long ride over the weekend with a new trial set of wheels, I
noticed one spoke that sounded particularly dull when compared with
others. Is this a good sign that something has loosened? Could the
tone produced by plucking spokes be used as a good monitor on the
condition of the wheel?

Any comments? I'm thinking of taking it back to the store and have it
checked out. --

Well, that the spoke has lost tension is one possibility. Make sure
there isn't some kind of cruft stuck in the spoke crossing closest to
the rim.

Umm, also make sure that this is not the spoke that has the computer
magnet on it....

--

David L. Johnson

__o | If all economists were laid end to end, they would not reach a
_`\(,_ | conclusion. -- George Bernard Shaw
(_)/ (_) |

Artoi said:

Thanks for the advice. Although there's some crossing of the spokes in
the rear wheel, they don't actually come into contact. So the dullness
wasn't through interference.

Wait a minute. They _should_ come into contact. If they don't, they are
improperly laced -- unless you are talking about some low spoke-count,
one-cross wheel.

Quoted message said:

So the obvious question here is, can one just touch up the tension at
home to equalize the tone?

If the tone is clearly off, but the wheel is still true (spin it and watch
the clearance with the brake pads, and look for up-and-down movement,
too), then maybe the rim has a flat spot. Just evening the tone is not
the whole story.

Quoted message said:

Or shouldn't one touch it except in a truing
stand? Of course, this is under the assumption that there's no flats or
other significant hardware issues with the wheel.

Don't assume that.

--

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

Jean who? said:

snip

Quoted message said:

Quoted message said:

I recently trued a wheel for a friend that was radially out by a few
mm and laterally had a wow or two. This wheel had some bad treatment
an had humps that mere spoke tensioning could not fix so I used my rim
curvature clamp After getting it radially true, I could take care of
the rest with manual rim bending and spoke tension.

Quoted message said:

Quoted message said:

These methods are explained in detail in "the Bicycle Wheel".

Quoted message said:

What is a "rim curvature clamp"?

It's an old tool that isn't made anymore because people are to rich to
fix rims and just buy a new one. It is a curved metal tool that
contacts the rim circumference for about a foot like a bridge with a
4.5 inch gap in the middle. A padded hook with a spoke gap reaches
down to go under the rim and pull it out with a T-bar tightener on a
1/2" fine thread screw.

The tool is called "RIM-TRUE STRAIGHTENER" made by Overland Inc.
Grand Rapids, Michigan.

http://tinyurl.com/hm5te

If the picture is still there. Unfortunately it is made for 27" rims
so the curvature doesn't exactly fit but that could be fixed with a
fly-cutter of the right radius.

Jobst Brandt

Art who? said:

Quoted message said:

Quoted message said:

Is the tone produced by plucking a spoke an important gauge of
even tension on the wheel?

Quoted message said:

Quoted message said:

I use it all the time when building wheels. I designate a "master
spoke" and measure the tension of that one with a tensiometer, and
then use my ears to bring the tension up evenly, checking the
master spoke's tension once in a while with the tensiometer.

Quoted message said:

Quoted message said:

Quoted message said:

After a long ride over the weekend with a new trial set of wheels,
I noticed one spoke that sounded particularly dull when compared
with others. Is this a good sign that something has loosened?
Could the tone produced by plucking spokes be used as a good
monitor on the condition of the wheel?

Quoted message said:

Quoted message said:

Quoted message said:

Any comments? I'm thinking of taking it back to the store and
have it checked out. --

Quoted message said:

Quoted message said:

Well, that the spoke has lost tension is one possibility. Make
sure there isn't some kind of cruft stuck in the spoke crossing
closest to the rim.

Machine built wheels have traditionally been under tensioned because
the spoke nipple turning mechanism does not feel spoke windup and
small adjustment end up being a bit of spoke twist where the thread
does not turn. You can imagine that this is an infinite loop of
making an adjustment, checking for alignment and repeating with no
evidence that anything happened.

For this reason "Spoke-prep" was invented so that loosely spoked
wheels would not unscrew their spokes in use. This is a crutch for
poorly tensioned wheels, that are bad in more than one aspect because
a loosely spoked wheel may be true mainly because the rim was true to
begin with so the sloppy spoke tension is too little to have an effect
on trueness. In use this works out to be a wobbly rim and one that
loosens spokes.

Help... Spoke Prep, Linseed oil. Loctite, etc.

Quoted message said:

Thanks for the advice. Although there's some crossing of the spokes
in the rear wheel, they don't actually come into contact. So the
dullness wasn't through interference.

From that I take it this is a low cost wheel. There is a reason for
interleaving spokes at the outer spoke crossing and that is to prevent
loosening when occasional overloads occur.

Quoted message said:

So the obvious question here is, can one just touch up the tension
at home to equalize the tone? Or shouldn't one touch it except in a
truing stand? Of course, this is under the assumption that there's
no flats or other significant hardware issues with the wheel.

By all means, tighten the spokes but be sure you understand what needs
to be done because the wheel will most likely become un-true when the
spokes begin to do their job. Just like patching tires, it is a good
idea to do your own wheels so that in the event of a problem you can
fix it on the road.

Quoted message said:

I note that the wheel came with a spoke adjuster.

I think you mean spoke wrench, in th wheel building jargon. That is odd.
from whom did you buy this?

Jobst Brandt

In article <[email hidden]>,
[email hidden] wrote:

Thanks again for your expert comments! 🙂

Quoted message said:

Machine built wheels have traditionally been under tensioned because
the spoke nipple turning mechanism does not feel spoke windup and
small adjustment end up being a bit of spoke twist where the thread
does not turn. You can imagine that this is an infinite loop of
making an adjustment, checking for alignment and repeating with no
evidence that anything happened.

Yes, this is most evident given the aero styled spokes on this wheel. I
could see the spoke turning with the nipple but without any alterations
in the tension. The wheels also came with a "spoke wrench for
aerodynamic spokes". I assume that is to keep the aero spokes pointed in
the correct direction while adjusting the nipples.

Quoted message said:

Quoted message said:

Thanks for the advice. Although there's some crossing of the spokes
in the rear wheel, they don't actually come into contact. So the
dullness wasn't through interference.

From that I take it this is a low cost wheel. There is a reason for
interleaving spokes at the outer spoke crossing and that is to prevent
loosening when occasional overloads occur.

It's actually a Mavic Ksyrium ES.

http://www.mavic.com/ewb_pages/p/produit_roue_ksyrium_es.php?onglet=2&gam
me=route

Quoted message said:

Quoted message said:

So the obvious question here is, can one just touch up the tension
at home to equalize the tone? Or shouldn't one touch it except in a
truing stand? Of course, this is under the assumption that there's
no flats or other significant hardware issues with the wheel.

By all means, tighten the spokes but be sure you understand what needs
to be done because the wheel will most likely become un-true when the
spokes begin to do their job. Just like patching tires, it is a good
idea to do your own wheels so that in the event of a problem you can
fix it on the road.

I am learning and do understand the physics of it. I took it to the shop
today and they did make some slight adjustment relating to the disc
position of the rear wheel. Otherwise the tech said the wheel is in
perfect shape. He said that it's not unusual for new wheels to need some
touch ups after early and/or long rides, a bit similar to all equipments.

I took it home and note that there's still one spoke that had a duller
tone. I used the spoke wrench and turned about 45-80* and that seemed to
equalized the tones. Until I get a truing stand myself or back to the
shop, I assume this is not excessive DIY at home. I'll ride a bit more
and see what happens.

Quoted message said:

Quoted message said:

I note that the wheel came with a spoke adjuster.

I think you mean spoke wrench, in th wheel building jargon. That is odd.
from whom did you buy this?

Yes, it's a spoke wrench, for adjusting the tension of spokes as you've
already pointed out. These spoke wrench (rear wheel), spoke wrench for
aerodynamic spokes (rear wheel) came with the wheels, but I have yet to
find company documents on how these should be used. The same thing goes
with the wheel bearing adjuster tool, again, there's no suggestion what
should be the proper spec for tightening.
--

In article <[email hidden]>,

David L. Johnson said:

Artoi said:

Thanks for the advice. Although there's some crossing of the spokes in
the rear wheel, they don't actually come into contact. So the dullness
wasn't through interference.

Wait a minute. They _should_ come into contact. If they don't, they are
improperly laced -- unless you are talking about some low spoke-count,
one-cross wheel.

Yes, as stated in an earlier reply, this is a Mavic Ksyrium ES and is a
20 spoke one-cross rear wheel with flat "aero" blades.

Quoted message said:

Quoted message said:

So the obvious question here is, can one just touch up the tension at
home to equalize the tone?

If the tone is clearly off, but the wheel is still true (spin it and watch
the clearance with the brake pads, and look for up-and-down movement,
too), then maybe the rim has a flat spot. Just evening the tone is not
the whole story.

Took to the LBS and tech said the wheel is perfectly round. I did what
you suggested (guess it's a poor man's version of a truing stand) and
all looked good.

Quoted message said:

Quoted message said:

Or shouldn't one touch it except in a truing
stand? Of course, this is under the assumption that there's no flats or
other significant hardware issues with the wheel.

Don't assume that.

Still learning here. I tightened around 45-90* and the tones has
equalized. Fingers crossed.

Truing and building wheels seemed to be very interesting. A bit of
hardware and lots of physics. I may just take on learning it. But I
think I should get a bicycle work stand first before moving onto a
truing stand.
--