Yoke stem thread?

[Chris]

Hi
Does anyone know what thread the yoke stem thread is?
Does anyone have a die or a thread file I can borrow?
UK
Got a nice set of alloy yoles but the threads a bit brused.

Thanks Chris

 

[L.A.B.]

Does anyone know what thread the yoke stem thread is?
Got a nice set of alloy yoles but the threads a bit brused.

Why not measure it?
If the yokes are alloy can you be sure the thread is standard?

According to the SB list, the pre-71 stem nut is 13/16 x 28
By my own measurement, the 71-on thread is 7/8 x 14 UNF.

 

[Chris]

Hi Lab

Thanks
13/16th 28tpi
In the middle of clearing the loft & cant get to my notes!
Measuring :shock: far to easy. Knew there were two thread forms, just needed the prompt.

Anyone with a die, thread file?

all the best Chris

 

[frankdamp]

IIRC, the early bikes had a 26 tpi "Cycle Industry" thread that was actually cut onto the yoke, not done with a die. There were "cycle" threads on all kinds of components until someone wised up to the non-availability of tools for them in the US market.

 

[rvich]

If you can find a spare nut, or buy one, make cuts across the thread with a sharp hack saw blade, then carefully screw it on to the yoke. It will do a pretty good job of cleaning up bruised threads. If it won't start on, I have cut a section out of a nut, about a third, and used it to clean up threads by starting with it on the shaft and working toward the end. Works well on bronze, so I suspect alloy too.

Russ

 

[Chris]

Hi
Thanks for your help/ Thread is 26tpi & I have ordered a die from Tracy tools.

all the best Chris