Headset Modification.

[stephan]

I have done this to a 1” Shimano 600 headset, it has been like it for 10 years now.

So you had an 1" 600 Threaded and made into a 1" 600 Unthreaded! Did you removed the threads within the inner top race and just fit over the steerer tube with no tapered wedge insert? Do you have any play?

 

[foxb13]

And what about the reverse: is it possible to thread a threadless steerer to convert from threadless to threaded headset?