I was on the first RAGBRAI in 1973 and 8 of the next 10. I haven't ridden it since, but was sorely tempted this year. It spends the night in Grinnell where I lived for 10 years from the late 1960's until the late 1970's. The OP described the ride as having 10,000 participants, but I think that's only the officially registered number. On any given day, that number can double. It's really a fun, social experience. On the first ride in 1973, there were 350 of us, and the ride was 6 days, not 7 . . .it was tough, but exciting.

Have a great time. It's a unique experience.

R.