I find it hard to believe that a Zweihander would only weigh 7 pounds.
It's actually true. The blades are relatively thin and light weight and while it is a two-handed blade they evolved from long swords and are meant to be wieldable with 1 as well. The heaviest a Zweihander should be is maybe 10lbs and that's really pushing it and probably more ceremonial than practical.
Edit: Rae makes me want to find my old books and reclaim lost knowledge.
I've gotta stop lazing around and do something.