Multi-Sport Transition Calculator

The model treats the two as separate skills that both improve with practice: base time drops from 15 minutes at first-timer down to 5 at elite in 2.5-minute steps, while the per-item gear-change cost falls from 4 minutes to 2 in 0.5-minute steps. That's because knowing your transition layout (base time) and being fast at swapping any one item (gear-change time) are learned independently — a racer can be well-organized but slow with buckles, or vice versa — so the calculator lets both dials move on their own experience curve.

The calculator assumes the pace penalty only applies to the first 1.5 km of running after a bike leg, at a 6 minutes/km baseline pace, then multiplies that distance-and-pace product by your slowdown percentage (25% for a first-timer, down to 9% for elite). It's a fixed distance rather than scaled to your total run length because the brick effect is a short-lived neuromuscular adjustment — legs recalibrating from spinning to striding — not a persistent fatigue that lasts the whole run.

Paddle transitions involve a completely different muscle recruitment pattern (upper-body/core rotation to leg-driven running) plus wet gear that adds friction to changing shoes and clothing, so the calculator adds `paddleLegsCount * (3 + (5 - experienceLevel))` minutes on top of the standard per-transition time — 4 extra minutes per paddle leg for a first-timer, shrinking to 2 for an elite. This is kept separate from bike-to-run brick effect because the two are physiologically different problems with different fixes.

It's a 0-100 score computed as `100 - (perTransitionMin / 20 * 50) - (gearChanges * 5)`, so it penalizes both a slow per-transition time and a high raw count of gear items swapped, independent of your experience level. Since gear changes are subtracted directly (5 points each), the fastest way to raise the score is cutting how many items you change per transition — pre-staged shoes or a quick-release helmet strap — rather than trying to move faster while still swapping the same number of items.

No — `bikeToRunKm` and `runToBikeKm` are collected but not currently used in any calculation; the brick effect is modeled against a fixed 1.5 km affected distance regardless of how long your actual legs are.