Threaded stem question relating to steer length and limit of spacers possible
 

On my current setup, I have the super-tall Nitto Technomic stem, because it makes my 51-year-old neck and shoulders feel so much better to put the bars up above the seat. I'm installing a new threaded fork, for a number of reasons, and as a NOS fork, uncut, the steerer is quite a bit longer than the steerer on the current fork. If I leave the new fork uncut, I could put a bunch of spacers into the new threaded headset that I will be installing and then use a stem that is not as tall as the Nitto Technomic, but still achieve the approximate same bar height. I figure the advantage to this is the lightness of alloy spacers compared to the extra length of the tall technomic stem. And I am guessing that the aesthetics might be better with a long steer with spacers instead of a cut steer in a more flush headset with that nerdy-old-man-tall Technomic.

If I go the spacers route, will it look crazy or ugly? And is there a limit to the amount of spacers you can stack on a threaded fork headset? The long steerer has plenty of threading depth on it, so I'm ok with threads if I must cut it, but I would rather not cut it if I can get away with it.

Comments, please?

You want the stem's quill expander to be below the threads in the steerer so you don't want the steerer so long the stem doesn't clear the threads. However, some steerers are butted and thicker walled toward the bottom. Your Technomic should work if it's not so far down that it hits any butted section. You can use spacers between the top race of the headset and the locknut with that caveat in mind.

Ah, gotcha. Thanks. The threaded section is weaker due to material loss when the threads are cut, and if the expander wedge is in the threaded section, it would distort of split the steerer? Is that the reason for the below-the-threads mandate?

Exactly.

Threaded forks allow greater adjustability than threadless forks. On the latter, you're limited in the number of spacers you can put in to raise the bar to an acceptable height and more often not you'll need a stem riser and an adjustable stem to get the fit dialed in.

On any threaded fork, the threaded portion has to extend far enough so that you can adjust the top race. Often forks with longer than necessary steer tubes are not threaded far enough for a shorter head tube. As already noted, the threaded portion is not as strong as the threaded portion of the steer tube. This means that even with a longer steer tube and spacers you cannot raise the stem and higher than you could with the steer tube cut to the minimum length