Tuesday evening our son (23) joined our small group ride -- 7 multi-geared road bikes and 1 fixie. He had his messenger bag as well.
Until this ride he'd not ridden more than 16 miles in an entire day. He did 35 miles total, quickly learned pacelining, and was in a breakaway of 3 fast rides for a couple miles. I was so proud of him!
He had a great time, and learned an important lesson: Wear proper shorts for a ride of this length.