On May 6, 1996, about 1145 eastern daylight time, a Cessna 172, N97277, landed hard during the landing touchdown at Winston- Salem, North Carolina. The airplane was operated by Piedmont Flight Center under the provisions of Title 14 CFR Part 91, and visual flight rules. A flight plan was not filed for the local, personal flight. The private pilot was not injured, and the airplane was substantially damaged. The flight originated about 1130, on the same day, at Smith Reynolds Airport, Winston-Salem. According to the inspector who examined the airplane, the nose landing gear was pushed up into the gear housing, and the main landing gear track was two inches wider than that specified in the pilot's operating handbook. The inspector stated there was also damage to the bottom of the airplane that was consistent with a hard landing. The pilot had been performing touch and go landings. He elected to end the flight with the onset of fresh stomach cramps from food poisoning the previous day. The pilot reported that the final landing resulted in the airplane bouncing. He pulled aft on the yoke, followed by a second touch down that was hard and on the nose wheel.