On July 8, 2000, approximately 1000 mountain daylight time, a Piper PA-18-150 (Super Cub), N4785F, was substantially damaged during landing at Tri-County Airport, Erie, Colorado. The flight instructor and pilot receiving instruction were not injured. The airplane was being operated by the Soaring Society of Boulder, Inc., under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the instructional flight that originated from Boulder, Colorado, approximately 30 minutes before the accident. No flight plan had been filed. The flight instructor said that the purpose for the flight was a currency check ride for a qualified tow pilot. He said the pilot receiving instruction performed a three-point landing, and the airplane bounced. The airplane immediately veered to the right following the second touchdown. The flight instructor took control of the airplane and applied full left rudder. The airplane subsequently exited the right side of the runway and ground looped. The main spar on the left wing was bent up. Postaccident examination, by the NTSB Investigator-In-Charge, of the tail wheel steering assembly revealed that the two chains/springs that controlled the tail wheel steering had an estimated 1 1/2 inches of slack in them. He also found that the chain was being held together by a "carabiner." A maintenance person said that the chains and springs connected to the tail wheel steering assembly "should be tight enough to give the pilot positive steering control." The maintenance records indicate that the airplane had accumulated approximately 4 flight hours since major rebuild.