boomhauer, I measured my Airstryke Z2 with the pads lowered and you'll need ~12" (~31 cm) clearance between the risers, most other aero bars should be similar. I had a set of Syntace C2 aero bars where each side mounted seperately and that type could narrow the space needed, but I lost the tops for an alternate hand position and the more narrow mounting, if needed for bar clearance may not fit you. I don't have the aero bars on my touring bike (slightly more upright than my road bike) and am waiting 'till I can get an all day ride in for evaluation.

Brad