I was pedaling along trailing this guy in a very serious mountain bike outfit the other day. Up and down hills our bikes rattled and skipped. He was a quiet rider, which I appreciate. After a few minutes he spotted me. And instead of grinding slowly up a climb, he began grunting and yelling, mashing his pedals and cursing loudly enough for anyone within a mile to hear when he didn't make it. I stopped and let him ride out of sight. If he's not comfortable with an audience, I don't need to make the guy yell. I was just hoping to follow him back to the trailhead since I'd been lost for an hour or more.