Pic related pretty much describes by question.
Retrofitting pinion brackets to aluminium frame. Pure curiosity rather than plan at this point.

Also I'd be interested if anyone here has successfully converted 1-inch threaded headset bikes to 1-inch threadless (or even 1 1/8 threadless).
I'd also be interested in extending threaded forks to be threadless using appropriately sized pipes like:
https://www.youtube.com/watch?v=TtOeCtNBUwg