Coffee Clunker Classic May 7th, 2011 - Green Bay
There is also a Chocolate Clunker ride in the Fall. They are dubbed clunker rides because of the ideal type of bike to ride on these occasions. None of those fancy "shifting" bikes. And coaster brakes would be perfect. If you don't have a true clunker you're still welcome to ride...at the end of the pack.
The pace is 'parade' and only goes ~15 miles with stops at area coffee shops. Awards for clunkiest, rustiest, etc are given. Last time I rode on a 20" Stingray.