I'm was 6'3" and 175 lbs. when flying mine for some years. Very comfortable even for long flights. In addition to overall height and shoulder width, another parameter is torso-to-height ratio: i.e., how long are your legs vs. upper body? It's less a factor for Libelles than for, say, the original Ventus/Discus cockpit. Mine had the raised canopy but the backrest was all the way back so my head was actually aft of the top of the bubble. I tried a low-profile canopy once and couldn't quite fit in. As others have said, the best way is to try one on. The parachute can make a huge difference so bring several with you. In my ASW 24, for example, the only chutes that work are very thin behind the shoulders with more bulk in the lumbar region, exactly the opposite of some chutes. The one I wore in the Libelle was an old Navy backpack that was almost certainly thicker than what I've used since then.

IIRC, the factory-approved water ballast system had some plumbing secured to the wing root rib in the leading edge (i.e., the fill port and connection to the dump tubes). I suppose those could squeeze one's shoulders a bit. Many (most?) early 201s (i.e, top and bottom surface dive brakes, balsa-core wings, small elevator) weren't retrofitted with the factory water system and instead used owner-provided barbed connectors for the tank tubes exiting the wing roots that didn't cause a shoulder clearance problem. Brings back memories!

Chip Bearden