Help With A British 3/8- 26 Tpi Thread?

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gi_984

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I'm working on an old Schwinn exercise bike. It dates back to the 1970's at least. It has an unusual thread pitch on the front wheel axle. It appears to be a 3/8-26 TPI with a rounded profile. After a little research it appears the British Standard Cycle (BSC) threads are 60 degree but with a rounded crest similar to the British Whitworth 55 degree threads.
Does anyone know if Schwinn did use this thread style? Better yet where can I find a tap?
 
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Yes, they came up on a google search I did. I'd rather not make a minimum order/ purchase a set etc. and deal with who knows how long it would take to ship from England only to find it isn't the correct tap! I'm hoping some of our Canadian members have some experience or suggestions? I am surprised Schwinn would use this type of thread. I just want to make sure I get the right one!
 
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Not sure what you need to tap. I am guessing you need to make an axle nut. It would probably be cheaper and possibly faster to just find a nut.
 
If it is a British Cycle thread and you are struggling to find a tap, then you could just go to a British Brass thread, which is going to be 3/8 - 26 TPI (but 55*). I dont think that minor difference in thread angle will matter in this instance.

Cheers Phil
 
Actually I'm making a very small pulley to fit the axle. This will be part of a belt drive for a peddle powered grain mill. There is very little clearance between the frame & forks. So I will be threading it on, then securing with a set screw, and installing the original axle nut.
 
Hi Phil,
I was looking at that (British Brass Standard) and wondering the same thing.
 
Please excuse me if I'm being a bit dense here but wouldnt the pulley remain still and not rotate if fixed to the axle?
Are you keeping the wheel so it will act as a flywheel?
 
I have made an adapter to fit a disk brake rotor to a wheel it wasnt designed for, if you would like some pics I will post them.
 
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