Col des Portes from Le Bourg-d'Oisans
Col des Portes from Le Bourg-d'Oisans: 28.7 km at 4.8% average and 1,383 m of climbing, up to 1,835 m.
- Distance
- 28.7 km
- Elevation gain
- 1,383 m
- Elevation loss
- 312 m
- Average gradient
- 4.8 %
- Start altitude
- 730 m
- Road
- Main road
- Surface
- Paved throughout
- Steepest 500 m
- 18.1 %
- Hardest 2 km
- 11.3 %
- Hardest kilometre
- km 26 · 11.1%
- Above 8%
- 6.0 km (21% of the climb)
- Difficulty index
- 4.8 Moderate
FIETS index: Δaltitude² / (10 × distance) + max(0, summit altitude − 1,000) / 1,000, lengths in metres. How this index works (article in French)
How long does it take?
| Level | Estimated time | Average speed |
|---|---|---|
| 2.0 W/kg — 140 W | 2h32 | 11.4 km/h |
| 3.0 W/kg — 210 W | 1h47 | 16.1 km/h |
| 4.0 W/kg — 280 W | 1h25 | 20.3 km/h |
Estimated for a 70 kg rider on a 9 kg bike, in still air, at a steady effort and without stopping. Wind, a stop at the fountain or a wheel to sit on move these figures by several minutes.
The route
Climb profile
- 10% and above
- 8 to 10%
- 6 to 8%
- 4 to 6%
- under 4%
Kilometre by kilometre
| Km | Gradient | Altitude at the top of the km |
|---|---|---|
| 1 | 4.9 % | 779 m |
| 2 | 5.1 % | 830 m |
| 3 | 8.0 % | 910 m |
| 4 | 5.9 % | 969 m |
| 5 | -1.4 % | 955 m |
| 6 | 0.7 % | 962 m |
| 7 | -3.4 % | 928 m |
| 8 | 5.1 % | 979 m |
| 9 | 4.8 % | 1,027 m |
| 10 | 5.3 % | 1,081 m |
| 11 | 0.7 % | 1,088 m |
| 12 | -3.2 % | 1,056 m |
| 13 | 1.8 % | 1,075 m |
| 14 | 2.4 % | 1,098 m |
| 15 | 2.8 % | 1,127 m |
| 16 | 2.7 % | 1,154 m |
| 17 | 6.0 % | 1,214 m |
| 18 | 4.4 % | 1,258 m |
| 19 | 7.1 % | 1,329 m |
| 20 | -0.5 % | 1,324 m |
| 21 | 4.2 % | 1,366 m |
| 22 | 2.3 % | 1,389 m |
| 23 | 6.4 % | 1,454 m |
| 24 | 4.8 % | 1,502 m |
| 25 | 3.2 % | 1,534 m |
| 26 | 11.1 % | 1,645 m |
| 27 | 9.7 % | 1,741 m |
| 28 | 2.6 % | 1,768 m |
| 29 (partial) | 4.7 % | 1,800 m |
Download the GPX track All climbs of this col
Frequently asked questions
How long is the climb to Col des Portes?
The hardest climb of Col des Portes, from Le Bourg-d'Oisans, is 28.7 km long for 1,383 m of ascent, i.e. 4.8% average.
How long does it take to climb Col des Portes from Le Bourg-d'Oisans?
Col des Portes from Le Bourg-d'Oisans takes about 1h47 at 3.0 W/kg, i.e. 16.1 km/h on average. The page gives three levels and their assumptions.
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