Brendan's cycling career began in the Upper Valley community at the Claremont Speedway Tuesday night points race series. He progressed through the ranks with the Killington Mountain School (KMS) junior cycling team, capturing a Junior National Criterium Title, before launching a U23 career with the Cal Giant Development team. His early success, highlighted by victories at the Redlands Bicycle Classic, earned him his first professional contract with the Hincapie Cycling Team. Rhim spent the next decade racing at the UCI continental level on the road, securing major international victories including the overall general classification and stage wins at the Tour de Beauce, Joe Martin Stage Race, and Kreiz Breizh Elites in France.
While competing in road racing, Rhim also excelled in collegiate racing while attending Furman University, as a freshman, winning multiple collegiate national titles (TTT, Road Race, and Criterium in 2015). A key turning point came in 2022, when he began transitioning from the road to the track. As a member of the Men's Team Pursuit Program since 2022, Rhim has captured five Pan American Track Championship titles (Team Pursuit, Madison, and Elimination) and secured a fifth-place finish in the Team Pursuit at the 2024 Track World Championships. His sights are set on the Los Angeles 2028 Olympic Games.
