For some reason a whole bunch of out-of-towners showed up for our regular Sunday ride, and someone forgot to tell them it was supposed to be a 19-23 mph pace.
Then halfway through we met up with the "A" group from the next town, and they decided to join us. So it turned into a hammer-fest, but happily they were content to let us lesser mortals suck wheel. We were rolling along at 27 mph for a while there. It was almost like motorpacing. 
Honestly my legs have been more fried with the regular group when it's been smaller and we keep the rotation going, but this was a whole different kind of workout. 54 miles, counting to and from the start.
Speed comes from what you put behind you. - Judi Ketteler