It was the largest concert crowd ever at the Adams County Fair on July 23rd when country singer Eric Church took the stage.    Dave Schroeder, Leah Rieke and Barb Maloney took registrations outside the grandstand for the KRVN Custom Ride.   There were six qualifiers drawn following the registration period.  They are Matt Rempe of Superior, Tom Shane of Hastings, Eric Cloet of Sutton, Marion Herbek of Lawrence, Cory Long of Hastings and Todd Jarecke of Firth.   Adam Smith hosted listeners with backstage passed before the concert and then introduced Church on-stage.    Local sponsors of the KRVN Custom Ride at the Adams County Fair included Wolfe Cycle Sports, CPI and Mr. Tire, Rave Revue, Gary Michaels Clothiers and The Pivot Man.