Longest commute was riding to the old Denver, Lutheran hospital 15 years ago, from our home in the mountains at 8,600’. It took 2h40m to get to work (avg 19 mph, max speed 52 mph), then 4.5 hours home with 4,800’ climbing. Maybe commuted that a dozen times over six years (otherwise commuted to Lafayette which was also some climbing on the way home). The past nine years I commuted from that mountain home to Longmont 1-2x/wk, which was 50 minutes downhill to work and 2h40m, 3,573’ of climbing to get home. We moved down to the flats two summers ago, I’m in my 60’s, now I commute every day, 7.2 miles each way, nearly flat course, 30-35 minutes. Easy peasy, love it.