Power what-if lab
Take any real ride from the Worlds, work out the power the splits imply, then add or take away watts — for the whole ride or for one rider's lap — and see the new splits and where it would have finished against the real field.
Power and aero changes
Physics assumptions
Model. P = ½ρ·CdA·v³ + Crr·m·g·v + Δ(½mv²)/Δt for each split, treating the team as one rider-equivalent at the front. Net power is what goes into air, rolling resistance and changes of speed; on a decelerating lap it is below the rider's pedalling power.
Held constant. Changeovers, their timing and the gaps between riders are taken as they were in the real ride. A change in power or CdA is applied to the split you choose and nothing else is re-planned around it.
Knock-on effects. In reality a change by one rider affects the riders behind them — the draft they get, the speed they inherit at the changeover, how much they have left. The only part of that the model captures is momentum: a faster split hands a higher speed to the next split, which at unchanged power then carries a small, decaying benefit for a few laps (roughly 0.1 s on the first following lap for +40 W over a kilometre, gone within five laps). Nothing physiological or aerodynamic about the following riders is modelled, so per-position and per-kilometre results are the direct effect plus that momentum term only.
Inputs. Absolute watts depend entirely on the CdA and mass you set; the time effect of adding a given number of watts is far less sensitive to them. Track, air density and line differences between venues are not modelled.