The new I-Zip bicycles recently added at Pat's 605 go 15 miles an hour with no pedal assist. The can go up to 20 if you add your own power. The bikes have various ranges depending upon the weight of the bike, the batteries used, and the terrain you are riding, but the lowest range is 18 miles, and the top of the line bike can go up to 35 miles on a charge.
Here is a short video of the products offered.