It does Not Matter .. I have 2 stems stacked on top of each other on my Tour/Trekking Bike.. with a steel steerer .

with a Carbon steerer The leverage of a High on top of the stack of spacers , seems to not be recommended, But People who buy carbon fiber race bikes

really don't Like to sit up much before the Finish Line.


May be a good High Place to Mount your Video Camera on top of it..