(First story) D.W. wants to ride in the bike-a-thon, but first she must get rid of those training wheels. (Second story) Arthur tries to avoid his pain-in-the-neck cousin, Mo, at the annual family reunion, but when a thunderstorm sends everyone inside Arthur's dread is transformed into a reunion to remember.
Text and photographs describe how the parts of a bicycle are assembled, how accessories are added, how inspectors check for defects, and how the bikes are shipped to stores across the country.