Yeah the shirt thing was kind of weird, we aren't really a "club," just a bunch of friends that like to ride old bikes at the beach... Supposedly the parade is listed as the oldest, biggest 4th parade west of the Mississippi. Don't know for sure but it was packed and went for miles...anyway, they have had bike groups in it before (a long time ago) and the problem is they pick up more riders as they go along the route and really turn it into a massive problem so they stopped. We sucked up to the organizers for a long time before they decided to give us a shot.
There were 1000s of people along the route on bikes. So by the rules, we had to ride in some kind of formation (we didn't), wear matching shirts and obey a lot of other conditions. They put us toward the end in case of problems and we had to police ourselves and boot anybody that tried to poach their way into the group...and there were a lot of people that tried to join in. Despite the conditions, it was an experience for sure...