I went to Boulder about 12 years ago, at a time when I was still riding around on a mountain bike with skinny tires. It was easy to rent a bike and I think I rented one from Performance. DS and DH were riding up the canyons, but I rode on the extensive network of trails through the city and out into the foothills, as well as a little bit on the roads. I've never been to any city that had the extensive type of trail network that Boulder has and it was perfect for me, at that stage of my riding.
DS was in a race (a well known one, can't remember the name), got second place, and they were apparently pissed an outsider got on the podium. They never sent him his prize...