I hate going up the hills, but LOVE going down them. I've hit 40 mph on a few. The only hills that really scare me are curvy ones where I don't know what's around the curve -- is there a car backing out of a driveway, a stop sign, a big dog, a pothole? Until I ride it a few times, I use my brakes on the curves. But once I can see ahead of my, I get as aerobic as possible and let it fly -- sometimes that gets me half-way up the next hill and that means less climbing !