KONAMETRICS
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90 km · 2025/2026 Data

Fastest Ironman 70.3 Bike Courses

Ranked by median finisher bike speed across the standard 90 km distance. Courses at the top are flat, smooth, and reward pure power output.

About course distances: Ironman occasionally shortens or modifies the bike course on race day due to weather, road closures, or safety conditions. When that happens, the average speed shown here will look artificially high because we always calculate against the standard 90 km distance. Races with unusually fast speeds may reflect a shortened course rather than exceptionally flat terrain — use them as a cue to double-check the race edition before drawing conclusions.

Bike Course Speed Rankings
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133 races shown. Tap a column header or use Sort by to re-order.

How We Calculate Bike Course Speed

Average bike speed is derived by dividing the standard Ironman 70.3 bike distance (90 km) by the median finisher bike split for that race. We use the median rather than the mean because elite professionals can distort average speeds on smaller fields. The median gives a truer picture of what a typical competitive age-grouper experiences on the course.

Higher km/h values indicate flatter terrain, better road surfaces, fewer technical turns, and often net-downhill or tailwind-assisted profiles. Lower values typically reflect significant elevation gain, technical cornering, or exposed coastal winds that affect the entire field uniformly.

Note that race-day weather — particularly headwinds and crosswinds — can shift a course's effective speed by 2–4 km/h year-to-year. Where multiple years of data are available, the most recent edition is used. If you are a strong cyclist, courses near the top of this list represent your best opportunity to bank time before the run.