Originally Posted by
Lazyrider
Exactly, it is possible but highly unlikely something that even a professional cyclist would set out to average on a solo ride. I mean, 25mph is pretty fast in a non-race situation and just on a daily training ride. 20mph is tough to "average" where I live simply based on congestion, lights and stops signs.
I've seen several claims that breaking 4 hrs for a solo century is a good bar for world class road racers.