@l i am said:
I am sure you will check 3 times for underpass headroom
:). I know it does not help you but perhaps others.
Thanks Liam, funny you should say check 3 times.
I did, and still went empirical anyway.
IE: I set the canopy frame up on temp posts and walked under it a few times.
SU gave me a good benchmark, (about 20 mm low.)
BTW: I am 6'4' and 3/4", 195cm.