Originally Posted by
justonwo
I think that would be highly dependent on how hilly century is, no? Where I ride, pretty much all rides have about 1,000 feet or climbing for every 10
miles.
Yes. That's why the range is 16-19 mph. Rough estimates, the pace tends to drop about 1% for every 5 feet/mile over 25. So most people will be about 15% slower on a course with 100 feet/mile than a course with <25 all else equal, so someone who can average ~19 on a flat course will likely drop to ~16 when there's 100 feet/mile.