Well, somebody had a vid of a helmet cam on a century, moving at what
looked like 25mph+ in rolling terrain on a lowrider, passing everything in
sight. My theory based on my own experience with rollers and groups is
that the bent(mine) has significantly lower air resistance and hence speed
dropoff is less so I fly over the next hill at 22-25mph where the higher
wind resistance of the DF riders + the hill means their momentum is chewed
up faster. The instantaneous demand for 250watts or more to keep up a
25mph speed up hill is just too much. I know that when I sit in behind a
group of DF approaching a short hill, I always have to pull out and frequently
pass the group because my speed is maintained where they slow up abruptly.
They always catch me if the hill is such as to drop my speed to below 12mph
though.