According to the accident report form submitted by the pilot, during the landing roll to a private dirt strip, the airplane began to veer off the left side of the runway. The pilot attempted to correct with right rudder; however, the airplane continued to the left. The airplane departed the landing environment and nosed over. The leading edge of both wings was crushed aft, the fabric wrinkled, several ribs were broken, and the firewall was wrinkled. The top portion of the rudder was crushed down. The pilot observed tracks on the ground "where the left tire was dragging like it had locked up." The pilot stated that the airplane does not have differential brakes. In addition, he reported that the master cylinder for the brake system is located a few inches above the exhaust muffler. He reported that when the cylinder is hot, it will result in the brakes dragging. An airworthiness inspector with the Federal Aviation Administration conducted an examination of the airplane systems, to include the flight controls, wheels and brakes. An examination of these systems revealed no anomalies. The inspector reported that the runway surface and shoulder were "very soft." Pictures of the runway environment revealed ruts from previous takeoffs and landings and the accident flight. The inspector reported that the ruts from the accident flight revealed the airplane touched down left of the centerline on the runway.