I'm a converted cross country runner to cyclist at age 24 and started biking this summer on a 96 Raleigh R600. I just got a computer and it tells me I'm averaging around 16-17 mph on a 20 mile ride with rolling hills. I'm 5'11" 175lbs, any idea if I'm doing okay. I really don't know how to compare myself to others, or if it really matters.