Courses · IRONMAN · Thun, Switzerland
The 2027 course · Powered by blamethecourse.com
179.2 km measured along the road and 1809 m of climbing read off the ground, in 12 climbs.
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.
78% of the IRONMAN Switzerland bike course is road where an aero position does most of its work: 139.8 km between −4% and +3%. 9.0 km (5%) climbs at 5% or more, where most riders sit up. What a TT bike is worth to you depends on your watts and how aero you are on each bike, so the page does not guess: ride it both ways in the predictor and compare the two.
| Kind of road | How much | Up |
|---|---|---|
| Steep, above 8% | 1.7 km | 168 m |
| Climbing, 5 to 8% | 7.3 km | 470 m |
| Climbing, 3 to 5% | 14.9 km | 585 m |
| Rising, 1 to 3% | 26.9 km | 532 m |
| Flat, −1 to 1% | 81.3 km | — |
| Descending, −4 to −1% | 31.6 km | — |
| Dropping, below −4% | 15.4 km | — |
The same kinds of road the predictor asks about: there you set the watts you will hold and how you will sit on each.
Each piece named by what the ground is: the climbs, the flats and the descents.
| Piece of road | Length | Slope | Rise |
|---|---|---|---|
| Flat, 2.6 km from km 0.0 | 2.6 km | — | 3 m |
| Climb, 1.1 km at 4.2% from km 2.6 | 1.1 km | 4.2% | 44 m |
| Flat, 1.3 km from km 3.7 | 1.3 km | — | 1 m |
| Climb, 1.2 km at 4.0% from km 5.0 | 1.2 km | 4.0% | 47 m |
| Flat, 10.6 km from km 6.2 | 10.6 km | — | — |
| Descent, 2.5 km at 3.3% from km 16.8 | 2.5 km | -3.3% | — |
| Flat, 8.4 km from km 19.3 | 8.4 km | 0.8% | 66 m |
| Descent, 1.4 km at 5.7% from km 27.7 | 1.4 km | -5.7% | — |
| Flat, 15.2 km from km 29.0 | 15.2 km | — | 65 m |
| Climb, 4.5 km at 3.6% from km 44.2 | 4.5 km | 3.6% | 159 m |
| Flat, 8.8 km from km 48.7 | 8.8 km | — | 4 m |
| Climb, 1.2 km at 4.4% from km 57.4 | 1.2 km | 4.4% | 51 m |
| Flat, 1.8 km from km 58.6 | 1.8 km | — | — |
| Climb, 1.8 km at 4.3% from km 60.4 | 1.8 km | 4.3% | 78 m |
| Descent, 2.4 km at 5.2% from km 62.2 | 2.4 km | -5.2% | — |
| Flat, 2.8 km from km 64.6 | 2.8 km | — | 4 m |
| Descent, 3.6 km at 4.9% from km 67.3 | 3.6 km | -4.9% | — |
| Climb, 2.2 km at 2.4% from km 70.9 | 2.2 km | 2.4% | 52 m |
| Flat, 4.4 km from km 73.1 | 4.4 km | 1.1% | 46 m |
| Descent, 1.8 km at 2.8% from km 77.5 | 1.8 km | -2.8% | — |
| Flat, 13.0 km from km 79.2 | 13.0 km | -0.7% | — |
| Climb, 1.0 km at 4.1% from km 92.2 | 1.0 km | 4.1% | 42 m |
| Flat, 1.3 km from km 93.3 | 1.3 km | — | 2 m |
| Climb, 1.2 km at 4.1% from km 94.6 | 1.2 km | 4.1% | 47 m |
| Flat, 10.6 km from km 95.7 | 10.6 km | — | — |
| Descent, 2.5 km at 3.3% from km 106.3 | 2.5 km | -3.3% | — |
| Flat, 8.3 km from km 108.8 | 8.3 km | 0.8% | 66 m |
| Descent, 1.4 km at 5.7% from km 117.1 | 1.4 km | -5.7% | — |
| Flat, 15.2 km from km 118.5 | 15.2 km | — | 65 m |
| Climb, 4.5 km at 3.6% from km 133.7 | 4.5 km | 3.6% | 159 m |
| Flat, 8.8 km from km 138.1 | 8.8 km | — | 5 m |
| Climb, 1.2 km at 4.2% from km 147.0 | 1.2 km | 4.2% | 50 m |
| Flat, 1.8 km from km 148.1 | 1.8 km | — | — |
| Climb, 1.8 km at 4.3% from km 149.9 | 1.8 km | 4.3% | 77 m |
| Descent, 2.4 km at 5.2% from km 151.7 | 2.4 km | -5.2% | — |
| Flat, 2.8 km from km 154.1 | 2.8 km | — | 4 m |
| Descent, 3.6 km at 4.9% from km 156.9 | 3.6 km | -4.9% | — |
| Climb, 2.2 km at 2.4% from km 160.4 | 2.2 km | 2.4% | 52 m |
| Flat, 4.4 km from km 162.6 | 4.4 km | 1.1% | 46 m |
| Descent, 1.8 km at 2.8% from km 167.0 | 1.8 km | -2.8% | — |
| Flat, 10.5 km from km 168.7 | 10.5 km | -0.9% | — |
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 180.1 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 2015 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.
179.2 km with 1809 m of climbing (10.1 m per km), in 12 climbs. 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.
78% of it is road where an aero position does most of its work: 139.8 km between -4% and +3%. 9 km (5%) climbs at 5% or more, where most riders sit up. What a TT bike is worth to you depends on your watts and how aero you are on each bike: ride both in the predictor and compare the two.
Climb, 4.5 km at 3.6%, from km 133.7: the most climbing in one go, 159 m. The steepest is Climb, 1.2 km at 4.4%, from km 57.4.
In the order you meet them: Climb, 1.1 km at 4.2% from km 2.6; Climb, 1.2 km at 4.0% from km 5; Climb, 4.5 km at 3.6% from km 44.2; Climb, 1.2 km at 4.4% from km 57.4; Climb, 1.8 km at 4.3% from km 60.4; Climb, 2.2 km at 2.4% from km 70.9; Climb, 1.0 km at 4.1% from km 92.2; Climb, 1.2 km at 4.1% from km 94.6; and 4 more.
That depends on you, so this page does not guess: open the course in the predictor. Set your weight, the watts you will hold on each kind of road and how you will sit, on a road bike or a TT bike, and it answers with your bike split and the band around it, climb by climb. Nothing to upload: the course is already there.