Spoke-cutting machine - durable results?



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John Albergo

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I recently had to replace a spoke and wasn't able to find the exact length pre-cut at the shop I
went to. However they did have a spoke-cutting device and I had a handful made up. The first spoke
popped during tensioning. I was able to put the wheel back into service with the second spoke, but
it broke after about 150 miles. I used my normal technique which includes lubrication of threads,
nipple, and eyelet along with stress relieving. Both of the replacement spokes broke in the threads.

Does anyone have experience with the relative durability of spokes produced by the shop device
(Park, I believe)? Aside from these being straight-gauge I'm wondering if there are potential
problems, perhaps due to wear, mis-operation, lubrication of the device, that would make such spokes
more suited to emergency or short-term replacements rather than permanent ones. Would you consider
informing the shop of the failures - perhaps there is something they need to examine?
 
B

Bill Putnam

Guest
John Albergo <[email protected]> wrote in message news:<[email protected]>...
> I recently had to replace a spoke and wasn't able to find the exact length pre-cut at the shop I
> went to. However they did have a spoke-cutting device and I had a handful made up. The first spoke
> popped during tensioning.
...
> Does anyone have experience with the relative durability of spokes produced by the shop device
> (Park, I believe)? Aside from these being straight-gauge I'm wondering if there are potential
> problems, perhaps due to wear, mis-operation, lubrication of the device, that would make such
> spokes more suited to emergency or short-term replacements rather than permanent ones. Would you
> consider informing the shop of the failures - perhaps there is something they need to examine?

The Park spoke cutter and thread roller when used properly produces an entirely satisfactory spoke
end. I have built over a dozen wheels with all spokes cut and threaded on a park machine, as I often
do non-standard combinations of rims and hubs. One rear wheel that I have built up with these spokes
has 15,000 miles on it without needing any attention.

Assuming that the spokes failed at the threads, and that essentially the threads on the spokes were
not well formed enough to hold on the nipple, this indicates either worn dies or improper operation.
I would definitely make the shop you went to aware of this problem, as this is not normal and
shouldn't happen.

Bill Putnam
 
J

Jobst Brandt

Guest
Bill Putnam <[email protected]> writes:

>> I recently had to replace a spoke and wasn't able to find the exact length pre-cut at the shop I
>> went to. However they did have a spoke-cutting device and I had a handful made up. The first
>> spoke popped during tensioning.

>> Does anyone have experience with the relative durability of spokes produced by the shop device
>> (Park, I believe)? Aside from these being straight-gauge I'm wondering if there are potential
>> problems, perhaps due to wear, mis-operation, lubrication of the device, that would make such
>> spokes more suited to emergency or short-term replacements rather than permanent ones. Would you
>> consider informing the shop of the failures - perhaps there is something they need to examine?

> The Park spoke cutter and thread roller when used properly produces an entirely satisfactory spoke
> end. I have built over a dozen wheels with all spokes cut and threaded on a park machine, as I
> often do non-standard combinations of rims and hubs. One rear wheel that I have built up with
> these spokes has 15,000 miles on it without needing any attention.

http://www.philwood.com/catolog2/page20.htm

I wasn't aware that Park makes a spoke threading machine although Phil Wood Tools does. If the dies
are worn or misaligned, they can make an unreliable thread. In any case, I would return the spokes
to the store and get some new ones, even if it takes some cutting and threading. By the way, if your
spoke length isn't much different than ones in stock, butted (swaged) spokes can be used, DT having
excessively long fat ends on their spokes. Make sure the shop is starting with good quality spokes
(DT, Wheelsmith, or the like).

> Assuming that the spokes failed at the threads, and that essentially the threads on the spokes
> were not well formed enough to hold on the nipple, this indicates either worn dies or improper
> operation. I would definitely make the shop you went to aware of this problem, as this is not
> normal and shouldn't happen.

Whether the treads are any good should be visible under a little magnification. There should be no
sharp valleys in the root of the thread.

Jobst Brandt [email protected] Palo Alto CA
 
P

Phil

Guest
> I wasn't aware that Park makes a spoke threading machine although Phil Wood Tools does. If the
> dies are worn or misaligned, they can make an

My bike shop has a really old, moldy Phil Wood roller/cutter that they used to make my spokes. It
apparently works great, because even after going down some stairs (intentionally) and basically
abusing my
700c/25mm commuter bike on my way to class to see if it'd fail, the 14 guage spokes hold just fine.
The spokes themselves don't have as clean a cut as the manufactured ones from DT, but they
thread on just fine. I prepped the spokes too.

Definitely tell your shop.

Phil, Squid-in-Training
 
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Jim Adney

Guest
On Thu, 09 Jan 2003 12:59:03 -0500 Alex Rodriguez <[email protected]> wrote:

>Make sure the device they are using is rolling the threads, not cutting threads. Cut threads are
>weaker than rolled threads. You can tell the difference because rolled threads will have a larger
>diameter than the spoke, cut threads have the same diameter.

I thought all spoke threads were rolled.

-
-----------------------------------------------
Jim Adney [email protected] Madison, WI 53711 USA
-----------------------------------------------
 
J

Jobst Brandt

Guest
Jim Adney writes:

>> Make sure the device they are using is rolling the threads, not cutting threads. Cut threads are
>> weaker than rolled threads. You can tell the difference because rolled threads will have a larger
>> diameter than the spoke, cut threads have the same diameter.

> I thought all spoke threads were rolled.

Yes, they must be, because the wire diameter for a rolled thread is smaller than the major diameter
of the formed thread. A cut thread on such a spoke would strip out for lack of engagement. I don't
know that anyone has seen a cut thread on a spoke in many years. No one has spokes with the right
diameter for cut threads.

Jobst Brandt [email protected] Palo Alto CA
 
A

A Muzi

Guest
"Phil" <[email protected]> wrote in message
news:[email protected]...
> > I wasn't aware that Park makes a spoke threading machine although Phil Wood Tools does. If the
> > dies are worn or misaligned, they can make an
>
> My bike shop has a really old, moldy Phil Wood roller/cutter that they used to make my spokes. It
> apparently works great, because even after going down some stairs (intentionally) and basically
> abusing my
> 700c/25mm commuter bike on my way to class to see if it'd fail, the 14 guage spokes hold just
> fine. The spokes themselves don't have as clean a cut as the manufactured ones from DT, but
> they thread on just fine. I prepped the spokes too.
>
> Definitely tell your shop.

The Phil machine is sensitive to setup. When the operator selects 14g or 15g mode, a precision gauge
is used to align and space the heads. This can be dead on or a thousandth up or down from correct.
When the thread form is not suitable, a resetting of the machine is indicated. A thread equal to
factory spokes is definitely attainable. And some days this is more starightforward than others as
the operator has to feel the setting which can easily be too tight or loose. A spoke is cut to test
the machine settings before beginning the actual job.
--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
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