On a straight road with a tailwind, 25.3 mph for 2:12 minutes on my current "comfort" bike, a Raleigh SC-30. Of course average speed goes down to 12 mph and I rode only 16 miles that day since I was exhausted hahaha!!!

I don't know if the computer is accurate measuring speeds, but I know that is giving me the right distances since I'm comparing it against my car's odometer.

A question to those that hit 40 mph or higher, How much time can you keep those speeds?