Originally Posted by
FBinNY
I prefer to keep the spacer stack under the stem less than 1" (25mm), though many go taller. If you do cut the fork, leave some room above the stem to make adjustments. You can always make another cut later on if you're 100% settled in to your riding position.
If you can do it with less stack height, I prefer small angle stems, ie. 6° because they're more versatile. Angled stems (not 90°) can be inverted to give you different HB heights. With high angle the difference is too much and only one is usable, but small angle stems give you 2 heights not that far apart, and combined with changing spacers lets you really dial in the position.
Anyway,
here's a link to a calculator that will show you graphic comparisons of 2 stems of varying length angle and spaced height.
Happy hunting
If I use my 25deg stem, I would still have 1.25" of spacers under the stem - that's my current setup. This may seem high, but I need this fit because of back issues. It may not be optimal for aerodynamics, but it's optimal for minimizing pain. So, it sounds like you would recommend sticking with the 25deg stem to avoid too high of stack height.