Probably the main ride is the COP Covered Bridge out of Cyclist Connection in Canal Winchester at 8:00am. COP has a weird policy on "pay for" rides about not releasing gps files unless you preregister because there might be 1-2 of you who will show up and ride without paying your $5 or $10 (set aside the fact that with a marked route, you 1-2 miscreants could do it anyway). I think the below is the century route but acknowledge a tweek could have been made.
The Cycling Club has a group ride from behind Veloscience in New Albany at 8:00am. I heard 15-20 come out for it but there is no route, you show up and ride for around 50 miles.