Yet another broken spoke

Qui si parla Campagnolo-www.vecchios.com wrote:
On Sep 2, 10:24 am, Just A User wrote:
It happened again! I broke ANOTHER spoke on my road bike. This makes the
second break in a month maybe a month and a half. Now I know I don't
have the lightest riding style compared to some riders. And I am not the
lightest of all riders. But then again I am riding on 32 triple cross
wheels. What I don't understand is why am I breaking them on the front
wheel only? I thought the back wheel carried more weight. So I have a
few extra spokes I bought when I had the wheel at the lbs for the last
spoke replacement. But now I am thinking that a new / better machine
built wheel, or cough, a handbuilt wheels might be a more reliable way
to go. When I say handbuilt, I mean with my hands, that have no
experience building wheels. All opinions welcome.

J.A.U.

Can you reuse the front hub? If ya can, get some spokes and a rim and
a coupla books and build the wheel..not rocket surgery. Or take or
send the hub to somebody and have them build ya a wheel...we do this
sort of thing all the time.


Yeah the front hub looks okay, it's a cheap hub anyway. The wheel
doesn't even look that bad. I just put another spoke in it and trued it
by eye, should be good enough until I can order a truing stand and give
it a proper job.

On Sep 2, 3:16 pm, Just A User wrote:
landotter wrote:
On Sep 2, 12:33 pm, clare at snyder.on.ca wrote:
On Sun, 02 Sep 2007 17:09:07 -0000, landotter
wrote:

On Sep 2, 11:24 am, Just A User wrote:
It happened again! I broke ANOTHER spoke on my road bike. This makes the
second break in a month maybe a month and a half. Now I know I don't
have the lightest riding style compared to some riders. And I am not the
lightest of all riders. But then again I am riding on 32 triple cross
wheels. What I don't understand is why am I breaking them on the front
wheel only? I thought the back wheel carried more weight. So I have a
few extra spokes I bought when I had the wheel at the lbs for the last
spoke replacement. But now I am thinking that a new / better machine
built wheel, or cough, a handbuilt wheels might be a more reliable way
to go. When I say handbuilt, I mean with my hands, that have no
experience building wheels. All opinions welcome.
A front is good to learn on. Sheldon Brown's site has good
instruction. The lacing seems hard till you do it three times, then
you can do it in yer sleep.
I like to stress relieve, AKA bed the spokes into the flange, after
I've tensioned the wheel up, by putting the axle on a block of wood
and working my way around the rim, giving it a pretty hefty push. Then
retrue. Should last you a lifetime.
Take your time building up tension, and do lace it up with an electric
driver from the back side so you don't get carpal tunnel issues.
And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

Ja--an alternative is simply to bring the current wheel up to tension.
Same goes for factory wheels--I dialed in my current set 3K ago and
have been over hill and dale with them and still they're bang on.
However, the current wheels' spokes have been stressed if they are
currently loose, undergoing the mysterious "coat hanger" effect, so
still a liability. If on a budget, it's worth a shot, though.

Well I think I am going to invest in a truing stand and then I will true
it out and see how it works out for me. In the mean time I just popped
another spoke in there and trued it out by eye. It's not perfect but
it's good enough to ride on for a bit.

Truing stand? You don't need no steenkin' stand for a touch up--rubber
band a pencil to the stays, or use the brake pads. Now, I gotta run
and JB Weld something...

On Sep 2, 11:24 am, Just A User wrote:
It happened again! I broke ANOTHER spoke on my road bike. This makes the
second break in a month maybe a month and a half. Now I know I don't
have the lightest riding style compared to some riders. And I am not the
lightest of all riders. But then again I am riding on 32 triple cross
wheels. What I don't understand is why am I breaking them on the front
wheel only? I thought the back wheel carried more weight. So I have a
few extra spokes I bought when I had the wheel at the lbs for the last
spoke replacement. But now I am thinking that a new / better machine
built wheel, or cough, a handbuilt wheels might be a more reliable way
to go. When I say handbuilt, I mean with my hands, that have no
experience building wheels. All opinions welcome.

J.A.U.

Just another opinion, but I cured all my spoke breakage problems by
getting a hand-built set of wheels four years ago. I've never broken a
spoke and haven't even had to re-true them once. They cost around $225
if memory serves me correctly. They were built on Ultegra hubs with
Mavic CXP-33 rims and a 36 spoke 3X pattern. I ride on rough
washboarded gravel roads and a lot of rough chip seal road. There are
lots of good builders around, including our own Pete Chisholm, Peter
White, and several others. A good set of hand-built wheels will give
you many years of service.

Smokey

On Sep 2, 3:11 pm, Peter Cole wrote:
Just A User wrote:
It happened again! I broke ANOTHER spoke on my road bike. This makes the
second break in a month maybe a month and a half. Now I know I don't
have the lightest riding style compared to some riders. And I am not the
lightest of all riders. But then again I am riding on 32 triple cross
wheels. What I don't understand is why am I breaking them on the front
wheel only? I thought the back wheel carried more weight. So I have a
few extra spokes I bought when I had the wheel at the lbs for the last
spoke replacement. But now I am thinking that a new / better machine
built wheel, or cough, a handbuilt wheels might be a more reliable way
to go. When I say handbuilt, I mean with my hands, that have no
experience building wheels. All opinions welcome.

J.A.U.

I would just bring the wheel up to (even) tension & stress relieve it
well. If it still breaks spokes, you could respoke.

I prefer to buy machine made wheels, simply because they're cheaper than
the parts and save some time lacing. I just tension & stress relieve.
I've done that on many sets of wheels with no breakage problems.

I've done that many times as well, before I took time to learn to
lace. I'd still do it for something common and good like Ultegra/OP/
DB, which is available for under $250 a pair online. Ten minutes with
a spoke wrench, and those wheels are good for years.

Clare who? writes:

And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

I keep seeing this admonition yet no one seems to be able to describe
the mechanism that causes such spoke failures. Loosely spoked wheels
can allow the nipples to unscrew and cause wheel misalignment, but
spoke failure is caused by metal fatigue that arises from tension
change, caused once with every wheel rotation as spokes pass through
the zone of tire contact with the road. This must occur with stress
near the yield stress, something that does not readily occur in loose
spokes.

Please explain.

Jobst Brandt

On 03 Sep 2007 02:19:47 GMT, wrote:

Clare who? writes:

And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

I keep seeing this admonition yet no one seems to be able to describe
the mechanism that causes such spoke failures. Loosely spoked wheels
can allow the nipples to unscrew and cause wheel misalignment, but
spoke failure is caused by metal fatigue that arises from tension
change, caused once with every wheel rotation as spokes pass through
the zone of tire contact with the road. This must occur with stress
near the yield stress, something that does not readily occur in loose
spokes.

Please explain.

Jobst Brandt


A properly tensioned spoke is "pre stretched" and does not flex or
stretch in operation. A loose spoke bends at leat twice every
revolution, and stretches repeatedly. This is what fatigues a spoke
and breaks it.

--
Posted via a free Usenet account from http://www.teranews.com

Clare who? writes:

And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

I keep seeing this admonition yet no one seems to be able to describe
the mechanism that causes such spoke failures. Loosely spoked wheels
can allow the nipples to unscrew and cause wheel misalignment, but
spoke failure is caused by metal fatigue that arises from tension
change, caused once with every wheel rotation as spokes pass through
the zone of tire contact with the road. This must occur with stress
near the yield stress, something that does not readily occur in loose
spokes.

Please explain.

A properly tensioned spoke is "pre stretched" and does not flex or
stretch in operation. A loose spoke bends at least twice every
revolution, and stretches repeatedly. This is what fatigues a spoke
and breaks it.

Please explain what bends the spokes. Rim deflection is a few
thousandths of an inch, the spoke holes in the flange have 10 to 20
thousandths clearance and spoke nipples much more. Where is this
fatiguing compression force arising? Spokes do not go into column
buckling when slack.

I have a feeling the concept requires some exaggerated model of a
spoke that is less than properly tight. The bending of which you
speak cannot occur and cause fatiguing stress. To do that the bend
would need to approach yield (permanent deformation). To see what
that is, try how much of a bend it takes to put a bend in a spoke by
manually using it as a walking cane.

Jobst Brandt

In article ,
writes:
Clare who? writes:

And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

I keep seeing this admonition yet no one seems to be able to describe
the mechanism that causes such spoke failures. Loosely spoked wheels
can allow the nipples to unscrew and cause wheel misalignment, but
spoke failure is caused by metal fatigue that arises from tension
change, caused once with every wheel rotation as spokes pass through
the zone of tire contact with the road. This must occur with stress
near the yield stress, something that does not readily occur in loose
spokes.

Please explain.

I can't.

But I /do/ know from empirical experience that once one
spoke breaks, its fellows are soon to follow.

I'm dealing with that right now, on my drive-side
rear wheel. Except once that first spoke broke, I
took the wheel out and swapped-in a less desirable
one, just to have some transportation, to keep my
favourite bike going. I've gotta buy 18 short spokes
pretty soon, because I want that wheel back. Hell, I
might as well respoke the whole kit-'n-kaboodle. Actually
I should buy a whole new wheel, as the rim is getting worn.
And I'm talking about a stress-relieved wheel that's put in
a lot of service, and has just ... had it.

Spokes are not immortal. Not even with featherweight riders.
Especially if they've got strong legs and lots of
vertical terrain to ride over.

Spokes get old, and just plain die.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

On 2007-09-03, wrote:
Clare who? writes:

And be SURE the spokes are tensioned adequately. Loose spokes break.
Tight spokes don't (as a general rule of thumb)

I keep seeing this admonition yet no one seems to be able to describe
the mechanism that causes such spoke failures. Loosely spoked wheels
can allow the nipples to unscrew and cause wheel misalignment, but
spoke failure is caused by metal fatigue that arises from tension
change, caused once with every wheel rotation as spokes pass through
the zone of tire contact with the road. This must occur with stress
near the yield stress, something that does not readily occur in loose
spokes.

Please explain.

I also thought that, and my reason was the same as Clare's. If a spoke
loses preload it might bend out of line resulting in enough moment to
produce yield stress (or close to it) at the elbow.

I admit I have absolutely no evidence that that's what happens, so I'm
glad you brought this up.

A properly tensioned spoke is "pre stretched" and does not flex or
stretch in operation. A loose spoke bends at least twice every
revolution, and stretches repeatedly. This is what fatigues a spoke
and breaks it.

Please explain what bends the spokes. Rim deflection is a few
thousandths of an inch,

Is that for a basically healthy wheel with one or two loose spokes or
for one where they are all so loose as to be losing their preload?

Or perhaps if they're all that loose the wheel will collapse anyway
making my question a red herring?

Just A User wrote:
It happened again! I broke ANOTHER spoke on my road bike. This makes the
second break in a month maybe a month and a half. Now I know I don't
have the lightest riding style compared to some riders. And I am not the
lightest of all riders. But then again I am riding on 32 triple cross
wheels. What I don't understand is why am I breaking them on the front
wheel only? I thought the back wheel carried more weight. So I have a
few extra spokes I bought when I had the wheel at the lbs for the last
spoke replacement. But now I am thinking that a new / better machine
built wheel, or cough, a handbuilt wheels might be a more reliable way
to go. When I say handbuilt, I mean with my hands, that have no
experience building wheels. All opinions welcome.

J.A.U.

has anybody yet bothered to ask the most important question? "what
brand are the spokes"???

this is the most important issue. you need to have good quality spokes
to resist fatigue - they're made from fatigue resistant material. if
your current spokes are some cheap no-name brand, i would re-spoke to
ensure reliability, especially as front wheels don't see as extreme
stress cycles as dished rears.