Multi-Location Analysis of Cycling Forces and Impulses Across Posture, Cadence, and Gear Ratio

This study aimed to investigate differences in forces and impulses at five rider-bicycle contacts (bilateral grips, saddle, and bilateral pedals) across posture, cadence, and gear ratio. In a randomized, repeated-measures laboratory design, 10 male and 10 female recreational cyclists completed 18 combinations of three seated postures, three cadences, and two gear ratios on a stationary indoor bicycle sensing system (50 Hz). Three-way repeated-measures ANOVAs with Holm correction examined body-mass-normalized vertical peak force, cycle-averaged force, and impulse per cycle at p < 0.05. Posture affected all three outcomes at both grips (p < 0.01, ηp² = 0.360-0.552) but not the saddle or pedals (p = 0.821-1.000, ηp² = 0.027-0.157). Cadence affected grip and saddle impulse and all pedal outcomes (p < 0.01, ηp² = 0.544-0.908); higher cadence reduced impulse at all contacts and increased pedal-force magnitude. Heavy gear increased all pedal outcomes and reduced all grip and saddle outcomes compared with light gear (p < 0.001, ηp² = 0.593-0.981). Interactions were limited, and sensitivity analyses reproduced all main-effect conclusions. Posture effects were concentrated at the handlebar, cadence primarily modified force-time characteristics and pedal-force magnitude, and gear ratio redistributed vertical loading between the pedals and other contacts. These findings support a purpose-dependent framework for region-specific mechanical load management in comparable indoor cycling conditions.