What thread pattern is this??

[Ron L]

I pulled the clutch on my cafe bike to clean the plates and noticed the clutch hub nut retainer wasn't seated properly, so I removed the nut and took the retainer over to the vise to "adjust" it. Well somewhere between the table lift and the workbench the nut ran off and hid. Even with a fair supply of extra clutch baskets, hubs, springs, etc., I had not one spare nut. Checked the size.... 5/8 X 20 tpi ?

$7.30 for a nut?? :shock: And it ain't even stainless! :lol:

That's not any CEI or Whitworth that I'm familiar with. Why would Norton use such an odd size thread here?

Moral to the story is don't lose that nut!

 

[norbsa48503]

Well now that you say so I have a bunch they hold the rear brake lever on a A-65 3.00 a piece.

 

[Coco]

You do realize that once you buy or order a new nut you will find the one that disappeared. I'll guarantee it.

 

[L.A.B.]

That's not any CEI or Whitworth that I'm familiar with. Why would Norton use such an odd size thread here?

It's 20 tpi Cycle thread, as far as I know.

Although most CEI/BSCycle threads are commonly 26 tpi regardless of the actual diameter, 20 tpi Cycle is not uncommon.


http://www.southwalessectionvmcc.co.uk/ ... hreads.pdf
"5\8 BSC 20"

 

[Ron L]

Thanks, Les, I was under the impression CEI was always 26 tpi. You've solved another mystery.

Coco, If I do find that nut it will assure me that I will never lose another! :wink: Besides, I'll need one for that other 750 MkV basket case that is waiting up in the loft.