Is the stack (spacer/shim) height on a 1" threaded headset determined by the headset or the fork?

For example, I'd like to get my headset (usable stem positioning area) as high as this one.

the headset or the fork? <-- BOTH.

U have smaller and larger headsets stacks and you can cut the steering tube as small as the headset u want to put in there, or longer as in the picture.

Good luck.

What if the current headset is shorter in height than the one in the pic?

As long as the threading on the fork's steerer tube is long enough to allow the top race to thread down enough to properly adjust the bearings, you can leave the steerer long enough to add a spacer stack between the top race and the locknut. I have one bike set up exactly as you show in the picture with about 20 mm of spacers between the top race and the locknut.

If I'm understanding you, then your fork will not have a long enough steerer to accomplish your goal. You'll need a new fork.

Your question is not really a headset question, it's the fitting of an (improperly sized)/overlength fork to a frame.

There's a long quill Nitto stem (see post #7) available to raise your handlebars.

If i understand right, what u need in that case is a super tall stem, second option is something like a steering tube extension but so far i know u will need another type of stem aswell, a 1 1/8 stem to be more precise. Maybe a 1 inch to 1 1/8 conversion kit will do the trick but no idea whats cheaper, a new fork or a conversion kit.

Thats a picture of the extension im talking about.




For the record never understood why people needs to ride with the handlebar so high, since in that position back pain is the 1st symptom, but well is not my back neither my bike

Good luck

The threadless adapter above will require a modern stem to work.

Nitto Techcnomic for will get your bars higher if that is your desire and keep that 1" headset.

When I first started riding frequently and for significant distance I had back pain from low bars. As I have been riding heavily and doing core exercises in the gym I can ride with the bars several inches lower than 3 years ago.

Don in Austin

Back pain and other pains are because the body position and weight is not well balanced in the bike.

BBB's BHP 21, as pictured [#6] but for 9/8" threadless ...
It got the steerer length up to where it would have been,
had I been at the assembly bench and said No!
when the steerer tube was about to be cut off too short, for my needs,
on a trekking bike, I bought [3rd hand].

with the added length I was able to add a second [threadless] stem
to mount the bar bag mount on it's own bar tube, lower and closer
to the axis, and still have room for a fork crown headlight mount under the bag...

and there still is a threadless adjustment thru that cap bolt,
because the design of the quill tightening bolt was brilliant.
It is internally threaded, 6mm inside a 6mm hex.

A strong core and overall fitness (in my case I should say "relatively" strong) certainly helps. That is my common element to less back pain. No two of my bikes fit exactly the same but I can now ride any of them for long distances with comfort. I am sure I could still ride with tall handlebars, but feel I have progressed past that.

Don in Austin

The only thing that improves my ability to ride lower, for longer duration at higher oputputs, seems to be weight loss.
It feels like my internal gut gets more crowded if I gain even a few pounds, so riding well means holding my poundage below 155.

I use a fair spacer stack under the stems of all of my bikes just to have the bars about 3.5 cm below the saddle. I have relatively long legs and a short torso for my overall height (5'9"). and a smaller frame, 55 cm or so, puts the bars way too low because I need so much seat post extension. A frame that lets me have a reasonable amount of seat post extension (57 cm) still requires about 30 mm of spacers plus a 6° up angle stem to get the bars at my preferred height.

I can only imaging how much of a spacer stack or how tall a quill stem I would need if I wanted the bars even with the saddle as many riders desire.