Home / Climbs / Col de la Croix de Fer
Col de la Croix de Fer
From Saint-Jean-de-Maurienne. Length and gradient from an official source; times from the climb time calculator.
- Start
- Saint-Jean-de-Maurienne
- 568 m
- Length
- 29 km
- Average gradient
- 6.5%
- Max gradient
- 10.5%
- Elevation gain
- 1,615 m
- Summit
- 2,064 m
Source: Route des Grandes Alpes, checked 14 October 2026.
North side from Saint-Jean-de-Maurienne. Secondary profiles often cite ~5.1–5.2% over a different start definition; this page uses RGA's 29 km / 6.5% / 1,615 m.
Time at your watts
| W/kg | Power | Time | Speed | VAM |
|---|---|---|---|---|
| 2.0 | 140 W | 3:09:00 | 9.2 km/h | 597 m/h |
| 2.5 | 175 W | 2:33:03 | 11.4 km/h | 737 m/h |
| 3.0 | 210 W | 2:09:21 | 13.5 km/h | 873 m/h |
| 3.5 | 245 W | 1:52:35 | 15.5 km/h | 1,002 m/h |
| 4.0 | 280 W | 1:40:09 | 17.4 km/h | 1,127 m/h |
| 5.0 | 350 W | 1:22:59 | 21.0 km/h | 1,360 m/h |
| 6.0 | 420 W | 1:11:44 | 24.3 km/h | 1,573 m/h |
Model estimate in calm air at steady power (Martin et al. 1998). 70 kg rider + 8 kg bike, tops position (CdA 0.358), Crr 0.0032, 15 °C, air density at the climb's mid-elevation. Mid-elevation 1,316 m (air density 1.047 kg/m³). Calculate yours / All climbs
Climb time calculator (prefilled) / All famous climbs