Originally Posted by squeakywheel
Ever notice that you don't see adults on BMX bikes? That's probably because you can only ride around with your A$$ lower than your knees for so many years before the pain starts.
I'm a 6'2" adult that fits comfortably on a 22" Macneil BMX.
Though, BMX's aren't for sitting on.
The seat is high enough to be pinched between my knees, and low enough that its out of the way.
I do really enjoy seeing elderly asian men on kids mountain bikes though. (It happens quite often around here). I'm just happy they're out on bikes.
Also, lots of people (my girlfriend included) like their seat a little lower for ease of mounting/dismounting/dabbing a foot in traffic, even though it means a less efficient pedal stroke.