At some shows the bikes are judged in different categories. Some classes are based on wheel diameter, country of origin, age, manufacturer, etc.
I prefer a judged show because there is a list of things that the judges look at on each bike.
The other type of judging is "Peoples Choice". This judging is accomplished by anyone that comes to the show. You pick up a voting slip and vote for your favorite bike. They also sell voting slips. If you really want to win, you can just buy the votes or bring a lot of your friends to vote for your bike.
Every show is different. Try to have your bike as clean and shiny as possible. Any memorabilia, photos, manuals, etc., should also be displayed in an orderly fashion with the bike.
The best way to learn about the shows is to just participate. You will learn very quickly how much work it takes to win.:wink: