Kat Diamond Kiyonaga’s journey into the world of motorcycles didn’t start with speed—it started with curiosity and a deep love for American culture, particularly the 1950s. When she met her husband, Mitsuhiro “Kiyo” Kiyonaga, her admiration for motorcycles turned into something much bigger. With his encouragement, she went from cautiously riding through canyon roads to setting an SCTA land-speed record of 105.657 mph.
In 2024, the team set four world records and two national records at the Bonneville Salt Flats, achieving a total of eight records.
In 2025, Kat and Kiyo took on one of their biggest challenges yet: the inaugural Motorcycle TransAm. Riding a 1910 Thor, one of the oldest and most demanding machines in the event, Kat tackled thousands of miles of backroads, weather, and mechanical challenges that Kiyo helped fix. Despite the immense difficulty of completing an endurance run on a motorcycle of that era, she successfully covered an impressive 1,450 miles, demonstrating the same determination, perseverance, and pioneering spirit that have defined her motorcycling journey
Kat’s determination and passion for vintage motorcycles have made her a standout in the community. She embodies the spirit of pushing boundaries, taking on challenges, and proving that with enough grit, anything is possible.