I haven't read all 7 pages, but seriously, how did it get to this? Have people never ridden in pairs before? Regardless of your understanding of physics, surely at some time in your life you've gone down a hill with a fatter or lighter person? Whenever I tour, there's always some big guy that I can't catch down the hills, and by the same token, if I'm chatting to one of the girls as we approach a hill, I just have to say "see you at the bottom", because I'd need to brake to maintain the same speed as her pedalling.

Pfft.