Originally Posted by
thirdgenbird
this is what i would (and may) do. im not a fan of adjustable stems for daily riding. both of these survived a sunday in hell:
The setup in the second picture is somewhat problematic. My understanding and the recommendation of at least some fork manufacturers is that you need to run a spacer under the stem. (Thus see Cancellera's setup in the first picture)
According to Trek:
Always place at least one 5mm spacer below the stem. This spacer
rests on top of the bearing cover, which also must be at least 5mm in
height. Alternately, do not place a spacer group that exceeds 40mm
in height collectively underneath the stem. With a carbon steer tube,
always place at least one 5mm spacer above the stem and below the
top cap
Not sure how much it increases the risk of a steerer tube failure. But putting in a 5mm spacer seems worth it if there's any significant risk.