I live in a very hilly area and the last two weekends rode two different hilly 20 milers averaging about 13.5 mph (about an hour and thirty five minutes.) I consider myself to be pretty fit, too. Both rides I was riding a road bike with cross tires. I'm sure I could have pushed it and gone faster (on some of the downhills we were doing like, 36 mph, and on the flats about 19/20 mph, but those looooooong "false flats" get me every time.)