"My top speed on a flat road is 32 mph. I can go about 1/2 to 3/4 of a mile. For anything longer, it's probably 20-22 mph"

I think you need to clarify your question a bit, seems like some 'peeps' are confusing top speed on flats vs. top sprinting speed which is TOTALLY not the same. A good sprint is usually about 500 meters give or take, whereas top speed on flats, riding the American River Bike Trail for instance, which is mostly flat, can be as long as 10-15 miles.

Just my 2 cents