On February 26, 2009, approximately 1230 central standard time, an experimental Neland Richard L. Dayton Super Cub, N170DN, sustained substantial damage when it flipped over during an emergency landing at Guymon Municipal Airport (GUY), Guymon, Oklahoma. The private pilot/owner was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the flight conducted under 14 Code of Federal Regulations Part 91. According to a Federal Aviation Administration (FAA) inspector, who responded to the accident site, the airplane's left main landing gear shock strut rod separated during take off from a farm field. The pilot decided to continue the flight to GUY and called emergency personnel to meet him at the airport. The pilot landed on the northeast grassy side of runway 06. The damaged landing gear shock strut rod impaled the ground during the landing, which caused the airplane to nose over on the left wing. The airplane came to rest inverted on the upper wing surface and rudder assembly. An examination of the airplane revealed that the pilot's center forward cross-over tube, left window center post fuselage frame, and rudder were substantially damaged. The airplane was equipped with 35-inch-wide tundra tires. According to the tire manufacturer, several operators of this make/model airplane are equipped with 31-inch-wide tundra tires and there have been no reported shock strut rod separations. The pilot/owner will install landing gear shcok-strut safety cables once the airplane is repaired.