Author Topic: Does anyone know the spoke thread diameter and pitch? (CB750)  (Read 9053 times)

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Offline markb

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Does anyone know the spoke thread diameter and pitch? (CB750)
« on: November 27, 2016, 01:15:20 pm »
As the subject line says I am trying to find the thread diameter and pitch for spoke threads. I figured it should be around here somewhere but my search attempt didn't work. 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.
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
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Offline jonda500

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #1 on: November 27, 2016, 02:50:51 pm »
someone asked a while back if these were the right ones to do spokes and nipples after re-plating - but there was no reply.. I'd also like to know?
John
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Offline 754

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #2 on: November 27, 2016, 03:07:16 pm »
Those would be 55deg inc angle thread...not sure what the spokes are.. Maybe 60 deg ?
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Offline markb

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #3 on: November 28, 2016, 10:39:48 am »
Those would be 55deg inc angle thread...not sure what the spokes are.. Maybe 60 deg ?
How do you know that?
So we're saying the spoke threads aren't metric? Maybe that's why I'm having a problem figuring out what they are.
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
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Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #4 on: November 28, 2016, 01:22:34 pm »
Those would be 55deg inc angle thread...not sure what the spokes are.. Maybe 60 deg ?
How do you know that?
So we're saying the spoke threads aren't metric? Maybe that's why I'm having a problem figuring out what they are.
They are 60 degree threads. I just checked a 42607-341-000 and found it to be an ANSI Unified Screw Thread: #6-40 thread.
At least I know the pitch is 40TPI and the diameters fall within the #6-40 specifications.
Not sure if all CB750 spokes are the same but I would expect they are.
« Last Edit: November 28, 2016, 01:25:34 pm by kmb69 »

Offline 754

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #5 on: November 28, 2016, 06:16:43 pm »
I would worry more about chasing the threads AFTER plating..not before...
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Online PeWe

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #6 on: November 29, 2016, 02:41:37 am »
This might be an answer? I do not know.
http://forums.sohc4.net/index.php?topic=47032.0
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Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #7 on: November 29, 2016, 09:06:24 am »
This might be an answer? I do not know.
http://forums.sohc4.net/index.php?topic=47032.0
That "thread" made me second guess myself, 55 vs 60 degrees, so I rechecked a NOS spoke.
Sure looks like 60 degree threads to me at 5x magnification. No light around my 60 degree thread form gage.
But the difference between 55 and 60 at that size could be deceiving. Definitely a rolled thread.
Gonna check a #6-40 tap in a spoke nipple tomorrow.


Online grcamna2

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #8 on: November 29, 2016, 09:26:51 am »
subscribed
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Offline jonda500

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #9 on: November 29, 2016, 04:27:34 pm »
Also subscribed - really hoping to end up with a link to the correct tap & die for our spokes without having to use trial and error (I don't have any spare spokes or nipples!).
John
Remember that an ignoramus is only someone who doesn't know something you just learned yesterday!

A starter clutch thread:
http://forums.sohc4.net/index.php/topic,122084.0.html
1972 CB500K1 original 4 owner bike
1972 CB500K1 returned to complete/original condition
1975 CB550F built from parts - project thread:
http://forums.sohc4.net/index.php/topic,149161.msg1711626.html#msg1711626
197? CB500/550 constructing from left over parts
1998 KTM 380 (two stroke) recent impulse buy, mmmm...

Offline markb

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #10 on: November 30, 2016, 06:31:48 am »
I would worry more about chasing the threads AFTER plating..not before...
I would probably do that too. Doing it before would make sure the threads were clean before plating. I'm not sure but isn't zinc an electro-plating process and that not much is going to get in the hole anyway? Maybe an expert could weigh in.

And I have been thinking about the threads. At first I was automatically thinking they would be metric but then it would surprise me if they were inch. But why would they be British?  ???I'm not saying they're not but it doesn't make sense to me. 
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)

Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #11 on: November 30, 2016, 06:45:59 am »
.....
And I have been thinking about the threads. At first I was automatically thinking they would be metric but then it would surprise me if they were inch. But why would they be British?  ???I'm not saying they're not but it doesn't make sense to me. 
Doesn't make sense to me either, but they are definitely 40 TPI and that does not match up to any metric thread pitch - 0.6349996571mm.
Pretty sure that only leaves the 2 aforementioned possibilities.



Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #13 on: November 30, 2016, 08:27:01 am »
Are these JIS threads? Here's a reference, but I'm not a mechanical engineer.
.....
Maybe, but I can not find a spec for a JIS 3.5m thread. Only 3m and 4m and neither has a .635m pitch.


Offline greenjeans

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #14 on: November 30, 2016, 09:09:16 am »
I would worry more about chasing the threads AFTER plating..not before...
I would probably do that too. Doing it before would make sure the threads were clean before plating. I'm not sure but isn't zinc an electro-plating process and that not much is going to get in the hole anyway? Maybe an expert could weigh in.

I replated the nipples and spokes on my K0.  No problem at all threading spokes after I got them plated (zinc).   

And I have been thinking about the threads. At first I was automatically thinking they would be metric but then it would surprise me if they were inch. But why would they be British?  ???I'm not saying they're not but it doesn't make sense to me. 
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Offline markb

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #15 on: November 30, 2016, 11:39:29 am »
Pretty sure that only leaves the 2 aforementioned possibilities.
I agree they're not metric.
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)

Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #16 on: November 30, 2016, 03:33:02 pm »
Still not sure exactly what it is, but I do have a little more info. This is bugging me!  :o
The NOS spoke and nipple that I am measuring appear to have slightly larger pitch diameters than either the 1/8-40BSW or the #6-40UNF.
Also pretty sure you can rule out the 1/8-40BSW because both spoke and nipple appear to have 60 degrees included thread angle.
A new #6-40 tap threads easily into the nipple but with a little more clearance than a normal #6-40 fit.
The spoke would probably not thread into a hole tapped with this tap. It would be seriously tight if it did.  ???
A little clearance or not goes a long way at these small diameters.
The minor diameter of the nipple is .119" or 3.0225mm. Essentially equal to Min PD for #6-40. Appears to be thread formed vs cut.
The major diameter of the spoke is .134" or 3.4035mm. Falls between Max/Min Major Dia for #6-40. Definitely a rolled thread.

Pretty much exhausted my ready resources and am wondering if maybe this is a custom, maybe even a proprietary Daido thread?   :-\


Offline markb

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #17 on: November 30, 2016, 04:25:41 pm »
Pretty much exhausted my ready resources and am wondering if maybe this is a custom, maybe even a proprietary Daido thread?   :-\
I am thinking I might try to contact Buchanan to see if they would provide that information. I could try tapping a #6-40 thread and see if the spoke fits.  ;)
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)

Offline kmb69

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #18 on: November 30, 2016, 05:18:34 pm »
Pretty much exhausted my ready resources and am wondering if maybe this is a custom, maybe even a proprietary Daido thread?   :-\
I am thinking I might try to contact Buchanan to see if they would provide that information. I could try tapping a #6-40 thread and see if the spoke fits.  ;)
Both good ideas. I just did not have time to do either.

Offline markb

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #19 on: December 04, 2016, 02:09:58 pm »
I emailed Buchanan and asked specifically for the thread size on 1969 CB750's. Their reply was: "We have no information on the OEM thread size for this model."  ::)
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)

Offline steve swan

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #20 on: December 05, 2016, 09:43:02 am »
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. 

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 and compare it's diameter 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


« Last Edit: December 05, 2016, 09:45:05 am by steve swan »

Online grcamna2

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #21 on: December 05, 2016, 09:56:38 am »
Thanks for your post steve swan.I like that new Hozan Ebay sold spoke threading tool;sure would be nice if it could be fitted w/ larger 'rolling/cutting' heads to work for motorcycle spokes if any of us were to find blank spokes 8 gauge or so.
I imagine the Hozan Co. in Japan might make a larger machine.
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Offline ttr400

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #22 on: December 05, 2016, 10:50:50 am »
I believe the thread is a BA size (British association). but i could be wrong.

Here are a couple of links.

http://www.voc.uk.com/net/docs/13.3/13.2-515-36.pdf

http://www.clag.org.uk/bascrew.html

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Offline steve swan

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #23 on: December 05, 2016, 10:54:26 am »
anybody got a BA thread pitch gauge ?  they're spendy on ebay

Offline 754

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Re: Does anyone know the spoke thread diameter and pitch? (CB750)
« Reply #24 on: December 05, 2016, 11:05:10 am »
Rolled threads are always larger than the shank or spoke (unless intentionally necked down)
No doubt they are rolled.
 And I am beginning to think the nipples may be done with a cold forming tap... Same process as rolling
 In rolling a male thread, 1/2 the thread is displaced inward..root of thread, the other 1/2 outward...crest of thread...... Even a blind man can identify a rolled thread...in most cases.

The Hozan tool, I have one, have not yet tried it but the guy I got it from rolled many heavy guage spokes for an XR 750.
 There is a pricey bicycle shop rolling tool that used flat dies (instead of rollers), it cuts the spoke to length and rolls the thread, in one pull of the lever.. They have dies for mc spokes but very costly.

 I have no doubt most spoke sizes are measured in wire guage sizes, like #9 and #11.
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way