Comparing 1" quill stems
 

When a stem measurement is given stating to minimun insertion point, it's this distance, correct?
https://cimg1.ibsrv.net/gimg/bikefor...21e1b1add3.jpg

According to yours and this other sketch, both seem to be correct:
https://cimg2.ibsrv.net/gimg/bikefor...c07f9a0d7e.jpg

Whether everyone plays by the same rules is another story?

Great diagram. Thanks!

Those aren't 1" stems though, they are 7/8" (22.2 mm), unless possibly French (22.0 mm) or Schwinn/BMX (0.833").

Inch quill stems exist, they fit in 1-1/8" ("OS") threaded steerers. Rare, because threaded went away a short time after 9/8" steerers became a thing. There was a brief window there, where steerers were OS but still threaded and used with quill stems.

Measuring the height of a stem that way is illogical, but of course people do illogical things all the time. If that's the accepted, conventional way to measure, then I won't fight it. But the only logical way is to measure the height to the centerline of the handlebar clamp. Otherwise two stems with the same height measurement (measured your way) could put the bars at wildly different heights. Like many inches difference, if the extension tube is angled up like a dirt-drop, versus angled down like a track bike. The height of the bar is what matters, not how long the quill tube is.

You could measure to the height of the horizontal line through the handlebar, but that's not really a measurement of the stem itself, since it depends on the head tube angle, which varies some between bikes. So I think stems should be measured to the line through the handlebar center that's perpendicular to the quill. So you can measure it right on the stem itself, without knowing what the head tube angle will be after it's mounted.
https://cimg6.ibsrv.net/gimg/bikefor...0ba19bac8f.jpg
But that's just me. The important thing is to say how the measurement was taken, otherwise the number is fairly useless.

Yah, should have said stems for 1” steerer tubes. Sorry. I figured since this was in the vintage forum, that would be clear.

Note Nitto measures them different ways depending on the model, quite illogical! (I wanna say "stupid" but maybe they have reasons?)
https://cimg0.ibsrv.net/gimg/bikefor...266ab3a608.jpg

Even with the classic "7" shape stems, they measure 'em two different ways. Note the Extension measurement, in pink, gives you a different number for the same size stem, they way they measure in the first drawing on the left compared to the 2nd drawing (top row middle). The difference is 5 mm. WOEWTT? (what on earth were they thinking?)

To get the length from the min.insert line on these, you'd have to know how far up from the bottom they put their line. I think it's about 65 mm, but I haven't measured one lately so don't trust me on that.

I still have a lot of respect for Nitto, but a bit less due to this crazy measuring system (or set of systems!)

Back before the "New Pearl" ("NP"), when their top of the line was just called Pearl, this is how they were measured (drawing from the box a Pearl came in):

https://cimg3.ibsrv.net/gimg/bikefor...29701cbc31.jpg

Note it's measured perpendicular to the quill, which is the method I prefer, but measuring along the extension (whether horizontal or not) is also OK, as long as you tell people which you're using. Nitto uses both!

Inch quill stems for 9/8" steerers are about 35 years old now, quite obsolete. Lot of newer stuff than that gets talked about here.

That Nitto drawing is wild. I thought Cinelli was silly for measuring along the top of the quill instead of perpendicular...but at least they are consistent