Bent spoke needs replacing?

Wayne Pein said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently broke a
rear spoke of mine near its midpoint. Another spoke has a couple of
closely spaced minor bends. When I rub my fingers over it I can feel it.
Does this spoke need to be replaced?
Thanks, Wayne

Yes, although it might last for thousands of miles. I wouldn't take
the risk when the cost is this low. That spoke would be operating
at a higher tension and carrying more of the load. Truing the wheel
with a kinked spoke results in a sub-optimal wheel. All spokes
shold run straight as a string stretched from the top of the nipple
to the hub hole.

--

Kind'a like the elbow? A kinky bend that lasts and lasts. Or the stress
riser at the threads - that lasts and lasts.

As to 'string', whattabout the bend at the crossings?

"daveornee" <[email hidden]> wrote in message
news:[email hidden]...
| Wayne Pein wrote:
| > In a race another cyclist crashed into me, causing me to go down.
| > Something, possibly a skewer or pedal, from his bike apparently broke
a
| > rear spoke of mine near its midpoint. Another spoke has a couple of
| > closely spaced minor bends. When I rub my fingers over it I can feel
it.
| > Does this spoke need to be replaced?
| > Thanks, Wayne
|
|
|
| Yes, although it might last for thousands of miles. I wouldn't take
| the risk when the cost is this low. That spoke would be operating
| at a higher tension and carrying more of the load. Truing the wheel
| with a kinked spoke results in a sub-optimal wheel. All spokes
| shold run straight as a string stretched from the top of the nipple
| to the hub hole.
|
|
|
| --
|
|

daveornee said:

Wayne Pein said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently broke a
rear spoke of mine near its midpoint. Another spoke has a couple of
closely spaced minor bends. When I rub my fingers over it I can feel it.
Does this spoke need to be replaced?
Thanks, Wayne

Yes, although it might last for thousands of miles. I wouldn't take
the risk when the cost is this low. That spoke would be operating
at a higher tension and carrying more of the load. Truing the wheel
with a kinked spoke results in a sub-optimal wheel. All spokes
shold run straight as a string stretched from the top of the nipple
to the hub hole.

I disagree. The bent spoke isn't really stretched or tensioned all
that differently. If there's not a visible nick in the spoke, and it
just a little kink, I don't think it's a bad idea.

I have plenty of wheels that have spokes that have bends in them from
race crashes. I've never had a spoke fail at one of those points...
all spoke failures I've had have been at the elbows (one wheel, the
flange doesn't support the spokes properly), or from heads popping off
the spokes (bad drill job in the hub flange).

Wayne Pein said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently
broke a rear spoke of mine near its midpoint. Another spoke has a
couple of closely spaced minor bends. When I rub my fingers over it
I can feel it.

Quoted message said:

Does this spoke need to be replaced?

Yes. Spokes that I broke recently had, on close inspections, kinks
from airline shipping where they threw the bicycle to the ground by
missing the baggage cart (by accident). Baggage mashers at airlines
hate bicycles and don't treat them well.

Anyway, such kinks have residual stress and also flex with each wheel
revolution. In a bind, the spoke could be hammered straight in place
and subsequently stress relieved. My kinks were first noticed when
the spoke broke a few thousand miles later. Last year these guys
ripped one of the spokes out of the wheel so that the nipple broke
rather than the rim. I was lucky.

This is a reason to use a bicycle suitcase. I have always used a soft
cover over the broken down bicycle because I can carry it in one hand
with my suitcase in the other when taking trains from the airport.

Jobst Brandt
[email hidden]

Wayne Pein said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently broke a
rear spoke of mine near its midpoint. Another spoke has a couple of
closely spaced minor bends. When I rub my fingers over it I can feel it.

Does this spoke need to be replaced?

Thanks,
Wayne

Thanks to all who responded.

Wayne

On Tue, 25 May 2004 16:05:27 GMT, Wayne Pein <[email hidden]> may

have said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently broke a
rear spoke of mine near its midpoint. Another spoke has a couple of
closely spaced minor bends. When I rub my fingers over it I can feel it.

Does this spoke need to be replaced?

I would replace it. I suspect that the wheel will be out of true at
the location of that spoke; this should be a hint that it's either
under added tension, or it's stretched and not under correct tension
anymore. Would you build a wheel using a bent spoke on purpose? No.
Then why leave one in when you have another to replace anyway?

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Doug Huffman said:

Kind'a like the elbow? A kinky bend that lasts and lasts. Or the stress
riser at the threads - that lasts and lasts.
As to 'string', whattabout the bend at the crossings? <SNIP>
|
|

The spokes should run straight from the crossing in both directions.

Take a look at how Sheldon Brown suggests stress relieving. I don't use
his "stress relieving" method, as such, but I use it for spoke alignment
at spoke crossings.

<http://sheldonbrown.com/wheelbuild.html>

Since the shortest distance between two points is a strainght line,
spokes handle the dynamic loads best when they are all straight.

--

daveornee said:

The spokes should run straight from the crossing in both directions.

Take a look at how Sheldon Brown suggests stress relieving. I don't use
his "stress relieving" method, as such, but I use it for spoke alignment
at spoke crossings.

this method bends the spoke at the place of contact between the old crank
and the point on the spoke closest to the cross (especially on high tension
wheels -- ie, rear drive side). it's pretty slight but even using a
small force it's still there and you can feel it if you run your finger
along the length of the spoke. is that not a problem? or is it strangely
just me?
--
david reuteler
[email hidden]

David Reuteler said:

Quoted message said:

The spokes should run straight from the crossing in both directions.

This is not necessary, the bend being insufficient to cause
significant stress. I have not seen a spoke break at this point even
though my ancient spokes have distinct fretting notches at that point.

Quoted message said:

Quoted message said:

Take a look at how Sheldon Brown suggests stress relieving. I
don't use his "stress relieving" method, as such, but I use it for
spoke alignment at spoke crossings.

Quoted message said:

This method bends the spoke at the place of contact between the old
crank and the point on the spoke closest to the cross (especially on
high tension wheels -- ie, rear drive side). It's pretty slight but
even using a small force it's still there and you can feel it if you
run your finger along the length of the spoke. Is that not a
problem, or is it strangely just me?

I don't recommend this method for that reason and because it is too
close to the hub where it introduces large side loads. Manual
over-tensioning with leather work gloves cannot cause kinks in spokes
and it is adequate if done forcefully. The crank in the spokes method
can exceed tension levels that are beneficial to spokes and can be
damaging to hubs where excess stress in spoke holes is not visible or
detectable until failure.

Jobst Brandt
[email hidden]

David Reuteler said:

daveornee said:

The spokes should run straight from the crossing in both directions.

Take a look at how Sheldon Brown suggests stress relieving. I don't
use his "stress relieving" method, as such, but I use it for spoke
alignment at spoke crossings.

this method bends the spoke at the place of contact between the old
crank and the point on the spoke closest to the cross (especially on
high tension wheels -- ie, rear drive side). it's pretty slight but even
using a small force it's still there and you can feel it if you run your
finger along the length of the spoke. is that not a problem? or is it
strangely just me?
--
david reuteler [email hidden]

Well, I don't quite use Sheldon's exact methods and procedures either,
but I can understand what you mean. I just took a sample of a few wheels
that I recently built and, with my method, I only feel transitions in
the spoke at the butts and at the actual crossings. My objective of
straight running spokes that follow the same path as a thread stretched
from top of nipple to hub hole, including a slight obtuse bend at the
crossing, is attained. Spoke alignement at the hub and nipple vary
significanly, depending on the construction of the hub and rim hole
openings. I hope I am clear in the results and objectives... without
going into giving the details of my methods and procedures used to
attain them. I stand ready to be illumated by a supeior methods and
procedures. Do we agree on the objectives?

--

Jobst Brandt said:

David Reuteler said:

Quoted message said:

The spokes should run straight from the crossing in both directions.

This is not necessary, the bend being insufficient to cause significant
stress. I have not seen a spoke break at this point even though my
ancient spokes have distinct fretting notches at that point.

Quoted message said:

Quoted message said:

Take a look at how Sheldon Brown suggests stress relieving. I don't
use his "stress relieving" method, as such, but I use it for spoke
alignment at spoke crossings.

This method bends the spoke at the place of contact between the old
crank and the point on the spoke closest to the cross (especially on
high tension wheels -- ie, rear drive side). It's pretty slight but
even using a small force it's still there and you can feel it if you
run your finger along the length of the spoke. Is that not a problem,
or is it strangely just me?

I don't recommend this method for that reason and because it is too
close to the hub where it introduces large side loads. Manual over-
tensioning with leather work gloves cannot cause kinks in spokes and it
is adequate if done forcefully. The crank in the spokes method can
exceed tension levels that are beneficial to spokes and can be damaging
to hubs where excess stress in spoke holes is not visible or detectable
until failure.
Jobst Brandt [email hidden]

In your book in the sectiong "Improving the spoke line" you wrote:

"In the cross-spoked wheel, the spokes bend as they enter the hub and
the rim. These bends should be supported at the hub by the flange and at
the rim by the nipple. The unsuported spoke shaft should lie in a
straight line between the last points of contact at the hub and rim. If
there is an unsupported bend in a spoke, it will flex with changing
loads causing fatigue and early failure."

I have spokes that are fretting at the crossings too. My objective is to
have the bend at the crossing move as little as possible during changing
loads. Since the crossing spokes cause a very small change in direction,
I apply manual forces the make a very small but very distinct bend at
the crossing. I do this after the spokes are aligned at the hub and at
the nipples. I have tesnioned the wheel and checked tension and tension
balance. This manual adjustment never effects the tension balance but
often effects tension to the point where another 1/4 turn or more is
needed to bring the wheel back into proper tension. My reasoning for the
distinct bend at the crossing is that the spokes will truly be following
the shortest distance and therefore moving as little as possible in
response to changing loads. The support that the crossing spokes provide
to each other may help or harm the objective, but I have yet to break a
spoke there.

Further illumination on this topic is welcome. Did I go too far in
attempting to attain the "Straight Line" objective?

--

Dave Ornee said:

In your book in the section "Improving the spoke line" you wrote:

Quoted message said:

"In the cross-spoked wheel, the spokes bend as they enter the hub
and the rim. These bends should be supported at the hub by the
flange and at the rim by the nipple. The unsupported spoke shaft
should lie in a straight line between the last points of contact at
the hub and rim. If there is an unsupported bend in a spoke, it
will flex with changing loads causing fatigue and early failure."

Quoted message said:

I have spokes that are fretting at the crossings too. My objective
is to have the bend at the crossing move as little as possible
during changing loads. Since the crossing spokes cause a very small
change in direction, I apply manual forces the make a very small but
very distinct bend at the crossing. I do this after the spokes are
aligned at the hub and at the nipples. I have tensioned the wheel
and checked tension and tension balance. This manual adjustment
never effects the tension balance but often effects tension to the
point where another 1/4 turn or more is needed to bring the wheel
back into proper tension. My reasoning for the distinct bend at the
crossing is that the spokes will truly be following the shortest
distance and therefore moving as little as possible in response to
changing loads. The support that the crossing spokes provide to
each other may help or harm the objective, but I have yet to break a
spoke there.

Fretting at spoke crossings is not dependent on whether the spokes
make a gradual or abrupt bend there. Fretting is caused primarily by
spoke elongation under torque and load, load being the larger effect.
As I said, spokes don't break at this place even after many thousand
miles. I have wheels that have close to 300,000 miles on their hubs
and spokes (with replacement rims) and have not experienced a spoke
failure at those points of contact. Spokes that broke were ones
damaged by being kinked from foreign objects (sticks on trails) or
baggage mashers at airports.

Quoted message said:

Further illumination on this topic is welcome. Did I go too far in
attempting to attain the "Straight Line" objective?

I don't think the effort achieves anything useful so you could skip
the operation on future wheels.

Jobst Brandt
[email hidden]

Werehatrack said:

On Tue, 25 May 2004 16:05:27 GMT, Wayne Pein <[email hidden]> may

have said:

In a race another cyclist crashed into me, causing me to go down.
Something, possibly a skewer or pedal, from his bike apparently broke a
rear spoke of mine near its midpoint. Another spoke has a couple of
closely spaced minor bends. When I rub my fingers over it I can feel it.

Does this spoke need to be replaced?

I would replace it. I suspect that the wheel will be out of true at
the location of that spoke; this should be a hint that it's either
under added tension, or it's stretched and not under correct tension
anymore. Would you build a wheel using a bent spoke on purpose? No.
Then why leave one in when you have another to replace anyway?

Perhaps, but my bike mechanic did a very good job of recovering all of
my spokes after an accident. His method was to flatten all of the spokes
with a flathead screwdriver, then stress-relieve and re-true the wheel.
It helped that he had to re-dish it anyway The wheel is now stronger
than it was before, and the only way you can tell the spokes were
damaged is by the scratches on them. I'm 210lbs and after about 630
miles they're still true.

Of course, replacing one spoke isn't very difficult. You just have to
take the tire and wheel tape off. You will still have to true it either way.

-Collin

On Thu, 27 May 2004 03:00:50 GMT, Collin <[email hidden]> may have

Quoted message said:

Werehatrack said:

... Would you build a wheel using a bent spoke on purpose? No.
Then why leave one in when you have another to replace anyway?

Perhaps, but my bike mechanic did a very good job of recovering all of
my spokes after an accident. His method was to flatten all of the spokes
with a flathead screwdriver, then stress-relieve and re-true the wheel.

If spokes are dear or unavailable, there's no good reason not to
straighten and re-use ones that have only slight bends. If new ones
are inexpensive and in hand, though, I prefer to replace.

Quoted message said:

It helped that he had to re-dish it anyway The wheel is now stronger
than it was before, and the only way you can tell the spokes were
damaged is by the scratches on them. I'm 210lbs and after about 630
miles they're still true.

This speaks well for your wrenchman. Keep this person happy.

Quoted message said:

Of course, replacing one spoke isn't very difficult. You just have to
take the tire and wheel tape off. You will still have to true it either way.

And since the OP had one spoke broken already, there was a good chance
that swapping out the bent one at the same time was only going to
require negligible additional work, or no additional work at all if
the bent one was to be removed for straightening. One replacement
spoke was needed anyway, so getting a second wouldn't be a lot of
additional hassle.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Doug Huffman said:

Kind'a like the elbow? A kinky bend that lasts and lasts. Or the stress
riser at the threads - that lasts and lasts.

As to 'string', whattabout the bend at the crossings?

careful doug, you'll expose a flaw in "stress relief" theory with
heretical comments like that.

Quoted message said:

"daveornee" <[email hidden]> wrote in message
news:[email hidden]...
| Wayne Pein wrote:
| > In a race another cyclist crashed into me, causing me to go down.
| > Something, possibly a skewer or pedal, from his bike apparently broke
a
| > rear spoke of mine near its midpoint. Another spoke has a couple of
| > closely spaced minor bends. When I rub my fingers over it I can feel
it.
| > Does this spoke need to be replaced?
| > Thanks, Wayne
|
|
|
| Yes, although it might last for thousands of miles. I wouldn't take
| the risk when the cost is this low. That spoke would be operating
| at a higher tension and carrying more of the load. Truing the wheel
| with a kinked spoke results in a sub-optimal wheel. All spokes
| shold run straight as a string stretched from the top of the nipple
| to the hub hole.
|
|
|
| --
|
|