40 miles round trip 2x per week on a mtb w/ schwalbe marathon cross tires. Ave. this summer for 36 rides has been 15.2 mph. Route is 1/2 Chicago city streets, 1/2 crowded bike path. Data from Garmin 605. The gps is addictive; can view the data in a myriad of different ways and makes it fun to compete with yourself.