Honda CB750 Sandcast

Anyone know the spoke thread diameter and pitch?

markb · 30 · 12155


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
i just ordered this so i can test if a spoke is in fact 1/8"x40 tpi at a 55' angle.
Did you receive it? Any results?
Thanks
Mark B
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?)


Steve Swan

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
yes, i received the gauge, it's laying on my work bench.  i keep looking at it and thinking of you, almost daily.  what's my excuse........ ???

i'll get to it today or else tomorrow.


Steve Swan

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
i just ordered this so i can test if a spoke is in fact 1/8"x40 tpi at a 55' angle.
Did you receive it? Any results?
Thanks

ok.  so i put a BSW (Whitworth) thread gauge to the threads of the spoke and there is no fit, as i suspected all along, the thread pitches are unique to spokes and nipples.  i'm pretty much convinced the fellow on sohc.4 knows exactly what he is talking about, the pitches major and minor thread diameters are different as well as the pitch count which is on account of the threads being rolled and not cut.


Steve Swan

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
i would suggest getting a sacrificial spoke or more as needed, some thread cutting fluid and a Rowe spoke wrench, put the sacrificial spoke in a vise and see how a nipple responds to the test.  then test the "cleaned" nipple on a non-sacrificial spoke.  unless the zinc is really globbed in the threads, i think you'll have success without too much effort.  i've used this method with good results in the past.


rickhahn

  • Newbie
  • *
    • Posts: 28
    • View Profile
 In the DimDarks in Merry old England there was a thread used on Bikes both push and motor called Cycle Thread, Which the closest thing to it is BA . The reason they had different threads on there motor cycles was so you had to purchase spare bolts etc from them. Maybe the spoke thread size is a result of this . It is only a thought .   


4pots1969

  • Hero Member
  • *****
    • Posts: 759
    • View Profile
I do not understand because there are too many technical terms... ??? ???
What is the problem on the spoke? The thickness of the zinc plating?


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
What is the problem on the spoke? The thickness of the zinc plating?
Yes. I have had some plated that were a bit tight.

Anyway, I have given up on trying to find a tap for the spoke nipples. My plan is to first soak the nipples in a rust remover. Then I found some small brushes that fit in the nipple. I tried it out on a couple by running the brush in and out with a reversible drill. It cleaned them out real nice. When I can finally get around to doing them I’ll send them out for plating. If any are a little tight I have some “spare” spokes that I can run in them try to clean them out. Not sure what else I can do at this point. Funny thing is I got steel and brass brushes. The steel one disintegrated on the first one. I don’t know if it was defective or the bristles were too stiff. But it looks like the brass one will work just fine. Here’s a pic of the brush.

Mark B
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?)


Garry32

  • Jr. Member
  • **
    • Posts: 84
    • View Profile
Hi I have just had two sets of spokes and nipples re-plated  and the rear wheel dressed up perfect but when it came to dressing the front wheel all the spokes would not even try to enter the thread in the nipple after a lot off head scratching and phone calls and enquiries on thread sizes etc I was approached by a retired motorcycle mechanic who told me to clean up every single spoke threads using my bench grinder with a wire wheel attached.The result was perfect. Which I assumed was just slightly removing some of the plating thickness.
Hope this works for all out there.
Garry🇬🇧😁
« Last Edit: March 05, 2017, 06:13:01 pm by Garry32 »


Garry32

  • Jr. Member
  • **
    • Posts: 84
    • View Profile
I do not understand because there are too many technical terms... ??? ???
What is the problem on the spoke? The thickness of the zinc plating?
yes you hit the nail on the head 4pots so to speak , that is the answer too much over plating.
Garry🇬🇧😊
« Last Edit: March 05, 2017, 06:19:02 pm by Garry32 »


Steve Swan

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
Mark, i assume you are using nipple grease before threading nipples to spokes.  fwiw, Buchanan's sells the grease specific to threading nipples to spokes.


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I will now. Didn't know of it. Thanks for the info!
Mark B
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?)


4pots1969

  • Hero Member
  • *****
    • Posts: 759
    • View Profile

markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
Sorry to say that I have been too busy to do much of anything. I haven't gotten my nipples replated yet. When I do I will post my results.
Mark B
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?)