Hey iam, I noticed the same thing when I was on a paved, level and straight bike trail. I ride a MTB with the stock knobby tires and front suspension, and there were these people on road bikes that were like humming birds. They would just zip buy me, then slow down to talk to their riding partner and then zip off again. And it looked like they were doing it so effortlessly, that's what got me. Heck, I thought maybe they had a top gear that was twice as big as mine.