Originally Posted by
leegf
It's partly aesthetics (quill stems do look nicer than even the nicest threadless headset), but more importantly, we have a front-mount bike baby seat, and it really works best with quill stems (have tried both threaded and threadless).
I was wondering why you were so keen on a threaded head set then BAM, you come out with a reason I definitely hadn't seen coming. Best of luck with your search. Maybe have a chat with Wabi or one of the other firms and see what they can make for you - sometimes the solutions are there, just not on the websites.