Spoke threads exposed on new wheel - Safe?

"B.C. Cletta" wrote in message
om...
"Josh Gatts" wrote in message
...
You could also measure the length of a nipple to the base of the slot
(N),
the length of the threading (T) on a spoke, and the length of exposed
thread
(E). If your existing spoke is length L, you buy spokes of length L +
N - T
+ E. Heh heh.

it's 56-TPI so 6 exposed will be 6/56 inches too long.

The OP has 6 threads exposed on the hub side of the nipple. So 6 exposed
will be 6/56 inch too *short*, right?

--Josh

wrote:
Josh Gatts writes:
I just noticed that Peter Chisholm has recommended just replacing
the nips with 16mm. That's probably the best & cheapest solution,
although it may look a little goofy.

That won't help much, the threads in most longer nipples not being any
longer than the short ones. It will only be a cover-up, not an
improvement in thread engagement.

Does that include DT: one of the most popular makes?

DT 2.0 x 16mm have 22.5 turns worth of thread, 12mm have 18.

I'm screwing nipple onto spoke (with an extra long threaded section) and
counting turns from the point where it engages enough to just hold, to
point where end of spoke is flush with top of head.

~PB

Pete Biggs writes:

I just noticed that Peter Chisholm has recommended just replacing
the nips with 16mm. That's probably the best & cheapest solution,
although it may look a little goofy.

That won't help much, the threads in most longer nipples not being
any longer than the short ones. It will only be a cover-up, not an
improvement in thread engagement.

Does that include DT: one of the most popular makes?

DT 2.0 x 16mm have 22.5 turns worth of thread, 12mm have 18.

That's not the way it was supposed to work. That would require a
different spoke length for the same ERD but different nipple lengths.
I hope someone who doesn't build wheels didn't mess this up. As you
see from this thread, ones first impression is that the threads should
be longer, when in reality they should not, all rim ERD's requiring
the same length spoke regardless of nipple type.

I have one inch nipples for wood rims that have the same length of
threads at the head end as medium and short nipples, the ones commonly
used on metal rims today... except for he aero crew.

I'm screwing nipple onto spoke (with an extra long threaded section)
and counting turns from the point where it engages enough to just
hold, to point where end of spoke is flush with top of head.

That's too bad. Where have all the experts gone???

Jobst Brandt

"Mark Vieselmeyer" wrote:

I also had less than ideal results with an OCR rim. I just built a wheel
with a Ritchey Aero Road OCR rim that spocalc lists as 606mm, and I ended
up with about 1mm protruding out the back end of the nipples. Looking at
spocalc again, it has in parentheses "ERD is nipple contact dia + 3mm for
nipples". Does that comment mean I needed to make some adjustment to the
numbers before plugging them into the calculator? I know I had the right
hub dimensions, because I verified them calipers. Anyone have a good
technique for measuring ERD?

My copy of Spocalc shows all Ritchey 700c rims as 606mm ERD, with a note
that says "Spoke Seat 602mm."

No mention of +3mm, but 602 + 3 would be 605mm which sounds like it would
have been perfect for you.

Art Harris

"B.C. Cletta" wrote:
or (B): simply measure the depth of the hole from the bead diameter,
622-mm for a 700c. don't forget to 2x it.

Ooh, I never heard that one. Clever!

Art Harris

"S. Anderson" wrote in message
. ..
"Dave S" wrote in message
om...
Last night, I built a new rear wheel for cross riding using a Record
36 hole hubs, a Ritchey OCR Comp rim (called Trekking on web site) and
DT 14/15 spokes.

On inspection, I noticed that the left side as 2-3 threads exposed all
around whereas the right side has 5-6 threads exposed. I'm comcerned
that the spokes are too short and I don't have enough threads embedded
in the brass nipples.

Is this wheel safe or should I rebuild it with longer spokes?

Rebuild it. 1 or 2 is ok in a pinch. 5 or 6 is NFG. Especially on the
drive side.

Cheers,

Scott..


Sorry guys, a question. Any spoke/nipple area failures I've ever had
(usually from objects being caught in the wheel) have either popped the head
off the nipple or torn the rim (once.)

Unless others have seen stripped threads, why would a shorter engagement
make a difference

Cheers
Hugh Fenton
Serbia and Montenegro - but that's another story

"Hugh Fenton" wrote:

Sorry guys, a question. Any spoke/nipple area failures I've ever had
(usually from objects being caught in the wheel) have either popped the
head
off the nipple or torn the rim (once.)

Unless others have seen stripped threads, why would a shorter engagement
make a difference

Less thread engagement means more load (and more friction) on the threads
that are engaged. In addition to a greater chance of failure, it could make
it harder to turn the nipples when truing.

Art Harris

wrote:
Pete Biggs writes:

I just noticed that Peter Chisholm has recommended just replacing
the nips with 16mm. That's probably the best & cheapest solution,
although it may look a little goofy.

That won't help much, the threads in most longer nipples not being
any longer than the short ones. It will only be a cover-up, not an
improvement in thread engagement.

Does that include DT: one of the most popular makes?

DT 2.0 x 16mm have 22.5 turns worth of thread, 12mm have 18.

That's not the way it was supposed to work.

Not supposed to work for what? I don't mean you're supposed to use all
the thread up, just that this test indicates that more of the nipple is
threaded. If I'm correct then 16mm would help if one has already selected
spokes that are too short and isn't doesn't want to change the spokes -
which is the OP's situation, I thought.

That would require a
different spoke length for the same ERD but different nipple lengths.

Required for what?

I hope someone who doesn't build wheels didn't mess this up.

Whom mess what up?

As you
see from this thread, ones first impression is that the threads should
be longer, when in reality they should not

Should? *Are* DT 16mm threads longer or are they not longer?

, all rim ERD's requiring
the same length spoke regardless of nipple type.

I have one inch nipples for wood rims that have the same length of
threads at the head end as medium and short nipples, the ones commonly
used on metal rims today... except for he aero crew.

I'm screwing nipple onto spoke (with an extra long threaded section)
and counting turns from the point where it engages enough to just
hold, to point where end of spoke is flush with top of head.

That's too bad.

The above was just a test - not done on a wheel.

Where have all the experts gone???

I would expect an expert to understand what I was doing and to write a
clearer explanation and correction if I was measuring the wrong thing
rather than speak in riddles. If I am right, then I expect experts to
know a DT 16mm nipple has a longer thread.

What is the best way of measuring the length of the threaded section
within the nipple?

~PB

Less thread engagement means more load (and more friction) on the threads
that are engaged. In addition to a greater chance of failure, it could make
it harder to turn the nipples when truing.

hey art

the only "engineering" argument for more threads is friction. all
stress anyalsis shows it's only the first 3 threads that take the load.
the rest are just along for the ride.

jb

Jobst- That won't help much, the threads in most longer nipples not being any
longer than the short ones. It will only be a cover-up, not an
improvement in thread engagement. BRBR

16mm DT nipples has 4mm more threads, starting the same relative place on the
nipp as 12mm ones...Sincle the spoke looks about 4mm too short, I would try
this $3.20 solution first, or have the LBS give you a few to try.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"