there are also some tandems where the front person is in a recumbent position. They can sit and relax while the power rider in the back does all the work!

lol. or the guy in the back can just push them into traffic!

I agree about the front rider needs to be the stronger one. A tandem
with two people on it weighs well over 300 lbs, when it starts going
it's like a freight train.
I guess part of my problem is I understand the physics of momentum all too well and I know it wouldn't take much to send me flying off the top !

we've fallen twice so far, at fairly low speeds. I managed both times to land on my feet while the captain went down with the ship..