In article , says...
In article , "Mike says...

Is a road bike as fast as I think it is?

No. I have done the experiment. On a paved bike trail with several required
stops for street crossings, a fair simulation of commuting, my average speed
measured by computer was:

road bike 14.1 mph, mountain bike 14.3 mph.

snipped

I, too, have done the experiment, and came to the opposite conclusion,
with the roadbike being 3 to 4 kph faster over almost any city route not
requiring curb jumping.

Rick