Originally Posted by
spivonious
edit: okay, it seems my visual memory is way off. It says it's only a 56 foot elevation change, and it's over about 1000 feet, so that's a 5.6% grade.
Visual perception is a very dubious way to estimate hills. A 3 degree/5 percent slope looks basically flat when you draw it on paper, but when you ride it for any distance it feels steep. My 20% hill looks to me like it's nearly 45 degrees when I'm riding it, but it's actually only about 12 degrees.
I remember being told in college that the surface of the earth, mountains and all, is actually smoother than the surface of a bowling ball. Scale makes a big difference in perception.