Bent spoke needs replacing?

Quoted post said:

Originally posted by Wayne Pein
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.

Quoted post said:

Originally posted by Doug Huffman
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]

Quoted post said:

Originally posted by David Reuteler

Bdaveornee 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] [/B]

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?

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]

Quoted post said:

Originally posted by Jobst Brandt

BDavid 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] [/B]

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

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.
|
|
|
| --
|
|