Peloton Drafting Simulator
Place riders on a 3D road, set wind and grade, and watch every rider's watts, drafting savings and fatigue in real time.
Power follows Martin et al. (1998): gravity + rolling resistance + aerodynamic drag, divided by 97.5% drivetrain efficiency. Drag uses the apparent-wind vector, so crosswind rotates the wake and the best drafting spot shifts to the leeward side (echelon). Shelter is an empirical fit: 0 m bike gap directly behind saves ~40% of aero power, 1 m ~31%, 3 m ~20%, 10 m ~9%, with Gaussian lateral fall-off; multiple riders stack with a 55% cap, and a close follower saves the leader ~2% (Blocken et al. 2018 magnitudes). Fatigue uses the W′ balance model with CP ≈ FTP: above FTP W′ drains, below FTP it recharges in proportion to the deficit; at zero the rider cracks and drops. Sex only changes the default W′ (F 190 J/kg vs M 250 J/kg) and recharge rate (F ×1.25; Ansdell et al. 2019/2020: lower W′ but faster reconstitution and better fatigue resistance in females) — individual variation dwarfs the sex effect, and W′ is editable.
Trend-and-magnitude reference, not CFD: yaw effects on CdA, corners, surface differences and accelerations are not modelled.