Im averaging about 20-22mph(35km/h) on a flat ATM. And i spin up the hills in the easiest gear. My legs are pretty well built right now. Im doing about 25miles 5 days per week. Half the trip is hills though, with one monster hill coming back into town. Ive taken 10-15 minutes off the same route (all dependant of wind) in the past 4 weeks.