Originally Posted by
Sy Reene
Tire clearance doesn't matter unless you're comparing two bikes that only differ by the tires that were installed.
Axle-to-crown is another word for fork length apparently. So I'm saying if you have two forks, both with the same length (or A2C), then nothing changes in terms of angles, reach or stack.
I think what he means is that the newer disc brake bikes, have a taller fork, to allow for larger tyres, and that affects stack. Much as you have also explained.
I have a road bike and a gravel bike, both with 16.2mm headtubes, but the stack is about 2.5cm more on the gravel bike.