Via: Dave Early
"The Gyronaut held the overall motorcycle speed record of 245.667. The body designed by Alex Tremulus who also designed a number of Ford Motor Company concept vehicles. Originally the plan was to put a Ford small block V-8 in the Gyronaut but it was later decided that a complete motorcycle concept was the way to go. Bob Leppan, co-owner of Triumph Detroit drove.
In October 1970 Bob returned to Bonneville and went head to head with a Harley Davidson Streamliner driven by A.M.A. flat track superstar Cal Rayborn. Harley snatched the record and Leppan was ready to respond.
The Gyronaut had been updated and the two Triumph Bonneville twins had been reinstalled, bored out to 750cc each. The following is a quote from Motorcycle Magazine;
"Then it happened. The thing that all high speed riders fear. Bob was winding out the Trumpet down the course at over 270 MPH approaching the measured mile. The front suspension collapsed and before any reaction was possible (like popping the drag chute) the bike started tumbling and rolling from side to side. Bob Leppan became a member of the Two-hundred MPH Crash Club and it nearly cost him an arm. During one of the gyrations of the Gyronaut, Bob's arm was ground into the hard-packed salt. The ripped and shattered limb was a candidate for amputation but Bob insisted on trying to save it. .....Bob Leppan is now recuperating from the highest speed "get-off" any biker has ever taken".
Bob never regained full use of his reattached arm. The Gyronaut never returned to the salt and a number of years later Triumph-Detroit, which had expanded into Jaguar and British Leyland car sales, went bankrupt."