Silly question - ahead stem on threaded fork

[JamesM]

Am I the only one that knows what a stress riser is?

If you doubled the wall thickness of the steerer and cut a thread into it, it would likely still be weaker than the standard thickness smooth steerer.

 

[We_are_Stevo]

Am I the only one that knows what a stress riser is?

No, we just didn't worry about it that much...

 

[JamesM]

Well if you push down or pull up on the end of the stem you are putting the steerer into tension. It won't bend it will tear and the threads will concentrate the stresses making it much easier for that tear to start. Bars would probably bend first though but who knows.

 

[We_are_Stevo]

But there are three examples above of people who have done just this without any negative results...

...which is what was queried in the OP; and it is a relatively shallow thread.