Anyone know the spoke thread diameter and pitch?

[markb]

As the subject line says I am trying to find the thread diameter and pitch for spoke threads. I measure 3.5mm diameter but I'm struggling with the pitch. I'd like to run a tap through the nipples before I get them plated.
Mark

[Steve Swan]

As the subject line says I am trying to find the thread diameter and pitch for spoke threads. I measure 3.5mm diameter but I'm struggling with the pitch. I'd like to run a tap through the nipples before I get them plated.
Mark

i "think" spoke diameters and thread pitches are specific to spokes.  "think" is the operative word here.......  i know in decades past, i used to have a spoke cutting (hand operated) tool, diameters and pitches were unique to spokes.  been long enough i can't remember. 

did you try a pitch gauge on the threads ?  if can measure the pitch and already know diameter, i'll bet you could type in the measurements and find a tap on ebay for cheap.

[markb]

Is it possible the threads aren't metric? 

[Steve Swan]

3.5 mm shank diameter is not "run of the mill."  i know all spoke threads are very fine pitch. i have never had occasion to put a pitch gauge to a spoke.

have you put a thread pitch gauge to the spoke ?  

until i am corrected, i DO believe spoke diameters and thread pitches are unique unto themselves.

might be a good idea to call Buchanan Wheel and see what they will share.

[Steve Swan]

Mark, this might be a valid answer, the fellow seems to to know what he is writing about

http://forums.sohc4.net/index.php?topic=47032.0

might be tine to ask Chris Rushton for a favor.........

[markb]

Steve, I saw that too. I am struggling with why they would be British threads and not metric or inch. 

I have a discussion going on the SOHC and there is even debate on whether or not the threads have a 55 or 60 included angle. Trying to track down a pitch gauge. I might try Buchanan. That would be an easy solution if they will share that info.

[Steve Swan]

i'll grab a spoke and throw a pitch gauge on it tomorrow.  if you'd shoot me a text as a reminder, that'll help me forget for sure........

[Steve Swan]

Mark, the thread pitch is neither Metric or SAE.  I don't have a BSW or Whitworth pitch gauge, so that's that.   I would say the fellow on sohc4 probably knows what he's talking about.  I am certain my memory from the past serves me correct in believing spoke diameters and pitches are unique unto themselves.  I'm sure Buchanan's would share what they know.  Spoke specs are not proprietary information.

[markb]

I was going to call Buchanan but in the end I just emailed them. I asked specifically for the thread size on 1969 CB750's. Here was their reply: "We have no information on the OEM thread size for this model."  Well I suppose they don't have to know if they make the spokes and the nipples because they can make them anything as long as they match. Never the less I found it disappointing that they didn't know.

[sandcastdoctor]

I WONDER, IF YOU SEND THEM A SPARE SPOKE, COULD THEY THEN DETERMINE THE THREAD PITCH ?

[Steve Swan]

i just ordered this so i can test if a spoke is in fact 1/8"x40 tpi at a 55' angle.  we shall see........  http://www.ebay.com/itm/302140360325?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[Steve Swan]

i have been giving this spoke thread pitch diameter more thought and asking people in the motorcycle industry what they know.  i rarely go to other Japanese forums, but Mark's comment he has been posting the spoke question over at sohc4 had me curious so i wanted to read what other people had to say.

i wound up posting on sohc4, but wanted to post on the DB i am loyal to.  here's what i posted on sohc4........

alright, i'll chime in my 2 cents worth.  Mark has been posting this same question on sooc db.  

my distant past memory, it seems somewhere i remember hearing spoke and nipple thread diameters and pitches are unique unto themselves.  As i recall, spoke threads are not cut with a die, they are ROLLED in a spoke threading machine using a rolling die head.  from what little i know, the threads are rolled to prevent microscopic tears in the steel that a die creates.  i've been researching since Mark posted on sooc, but find little on the topic specific to Honda or motorcycles for that matter.  

i put metric and sae thread pitch gauges to a spoke, neither fits.  i have 20/20 vision at 2 inches without glasses and saw lots of air on every gauge i tried.  i have ordered a bsw thread pitch gauge to test the bsw theory for myself.  

if you stop and think about the physical nature of a spoke, they ARE special.  the shank diameter IS smaller than the diameter of the threaded portion of the spoke.

the other thought is the possibility spokes are measured in wire dimensions.  i know some spokes are measured in different "gauges."  perhaps the test would be to put a mike to the spoke shank and it's threaded portion and compare these diameters to wire gauge diameters.

i'm sure greater minds than mine will prevail.

from my earlier times, i remember cheap spoke threading dies for motorcycle work being available to the home workshop.  a couple people i know have said they don't work worth a crap.

i've done a bit of googling to find information on motorcycle spoke threading and come up short.  When i saw the name "Hozan," it sparked a memory of seeing Hozan machines in Dealer's parts distributor catalogs.  K&L Supply has always been a great source for tool and i don't know if Flanders is still around, perhaps those are resources for spoke threading machines.

links to play with

http://www.caimag.com/forum/showthread.php?9003-Spoke-Thread-Machine

http://www.hozan.co.jp/cycle_e/catalog/_wheel.html

http://www.ebay.com/itm/HOZAN-C-700-Spoke-Threader-14-and-15-Gauge-JAPAN-NEW-Great-Tool-/162306046965?hash=item25ca31bbf5:g:WacAAOSwrklVa6bu

[markb]

Steve,
You beat me to it. Ordering those taps was going to be by next step. I have a feeling that they will be correct. At this point I will probably wait for confirmation from you before I buy. I appreciate you spending so much time on this. I thought this was a simple question. 
Mark

[Steve Swan]

Mark, i don't know why stuff like this pulls my trigger.......  for the sake of learning i guess.  i'm glad to see Keith is stumped over on sohc4.  probably because he thinks all people do in Colorado is stay stoned.  Keith........?!  Keith.........!?  Come home, Keith.......

i see someone on sohc4 says he thinks threads are BA.   the BA gauges are spendy and that is old pre-WW2 thread.

another thread pitch would BSF.......

we'll see what the Whitworth gauge does when i get it.  i'll be surprised if there is a fit.   i think Keith has already called it.

[Steve Swan]

here's an interesting link to shed a bit more light.  i am guessing there is no such thing as a conventional readily available tap or die to fit rolled threads on spokes or nipples......   http://www.central-wheel.co.uk/spokes/spokes.html