I rode last year for one day unregistered. They do offer single day registrations, but I had my sister picking me up and dropping me off. She could provide support if needed.

I understand that a substantial number of riders are unregistered. I recently spoke to a person who belongs to a team of baggers that ride unregistered each year. I even heard of a radio station in Waterloo that had a contest sending one lucky person to the start town with $5 and no bike and challenged them to finish the ride. I never heard the outcome, but if you had the right personality, it could be done.

The pass does get you discounts at vendors and repair stands. If you use RAGBRAI's luggage truck, ambulances, or SAG, you will need a pass. I also understand, if you are unregistered and try to use the SAG, they will charge you the price of a single day pass. Sounds fair to me.