Courses · IRONMAN 70.3 · Westfriesland, The Netherlands
The 2027 course · Powered by blamethecourse.com
91.5 km measured along the road and 7 m of climbing read off the ground, none of it long or steep enough to count as a climb.
Predict my bike split Your weight, your watts on each kind of road, road bike or TT bike: the course is already loaded, nothing to upload.
A model, not a measurement. What it can show depends on the numbers above — what you typed, and what your files recorded — and on assumptions this page states; anything it cannot stand behind says so rather than drawing a tidier line.
Each piece named by what the ground is: the climbs, the flats and the descents.
| Piece of road | Length | Slope | Rise |
|---|---|---|---|
| Flat, 91.5 km from km 0.0 | 91.5 km | — | — |
This page describes the road; how long it takes depends on who rides it. Set your weight, the watts you will hold on each kind of road and how you will sit, and the predictor answers with your bike split and the band around it, climb by climb.
How the road was measured
The length is measured along the mapped roads (OpenStreetMap), which all of the route followed, rather than along a GPS trace, which is longer or shorter than the road by however far its receiver wandered. The course file itself said 91.3 km, and a head unit measuring its own trace will read something close to that.
The climbing is read off a terrain model of the ground, averaged along the road, rather than off a barometer, which cannot tell a change in the weather from a hill. A terrain model is the bare ground, so a bridge or an overpass reads as what is under it. The file's own altimeter said 0 m, near enough the same road.
The course as described from the course IRONMAN published for 2027. watts & time is not connected with the event or its organisers; a course changes from year to year, so check the current one before you plan on it.
91.5 km with 7 m of climbing, none of it steep or long enough to count as a climb. The distance is measured along the mapped roads (OpenStreetMap) rather than a GPS trace, and the climbing is read off a terrain model of the ground rather than a barometer, which drifts with the weather, so a head unit will often show slightly different figures.
That depends on you, so the page does not guess: open the course in the predictor. Set your weight, the power you will hold on each kind of slope and the position you will ride in, and it answers with the time and the band around it, climb by climb. Nothing to upload: the course is already there.