Bike fit: biomechanical bicycle adjustment

Process of adjusting riding position to optimise efficiency and prevent injury.

Bike fit is the adaptation of bicycle geometry (saddle, bars, stem, aerobars) to the athlete's body and goals. For long-distance triathlon, a good fit must solve a dual objective: an aero position to reduce CdA (aerodynamic drag) while preserving muscular capacity for the run. A poor fit causes pain (knees, lower back, neck), reduces power transfer and fatigues muscle groups that should not be engaged. Key elements: saddle height (knee angle 25-35 degrees), saddle setback (KOPS), drop handlebar vs aero pad, torso angle and reach.