Alpe d'Huez via the Col de Sarenne
Road cycling
- Distance
- 52.2 km
- Elevation
- 1,705 m
- Est. time
- 2 h 40
- Power
- 220 W
- Max altitude
- 1,988 m
- Type
- Loop
Col de Sarenne: 12.8 km averaging 7.5%, 13.5% at its steepest, 954 m of elevation gain from the Chambon dam. The full loop is 52 km with 1,705 m of elevation gain.
Time and power estimated for a 75 kg rider at 220 W, climbing without stopping. Route from OpenStreetMap, altitudes from Copernicus.
From Le Cosy Lodge, take the D1091 and the Commères ramp up to the Chambon dam. That's where the real climb begins: 12.8 km averaging 7.5%, with a first kilometre at 11.5% up to Mizoën, then the hamlets of Clavans and a string of hairpins to the Col de Sarenne, at 1,999 m. This is the side the 2026 Tour de France rated hors catégorie. A narrow road with hardly any cars, between the Grandes Rousses and the Plateau d'Emparis. Over the top, the pastoral road plunges down to the Sarenne bridge, a short climb takes you to the Alpe d'Huez altiport, then the 21 hairpins bring you back down to Le Bourg-d'Oisans.
- The side rated hors catégorie on the 2026 Tour de France
- 12.8 km averaging 7.5%, with ramps of 13.5%
- Back down via the 21 hairpins of Alpe d'Huez
- Summer
- Road rideable from May to October, weather permitting.
- Winter
- Closed in winter · reopens in May
Set off with two full bottles: after Clavans-le-Haut there's no real village until Alpe d'Huez, and the mountain hut at the col only serves food in high season. Best to leave early for cooler air and calmer traffic on the D1091, with a windproof in your pocket for the col.
Four tunnels on the D1091 up to the dam, including the Commères, the longest (about 400 m): switch on your front and rear lights, and stay alert to the traffic on this Grenoble-Briançon route, which is busy in summer. After the col, the pastoral road on the Alpe d'Huez side is narrow and bumpy, with no crash barriers, a few fords and a 20 km/h limit: take the descent slowly, and watch out for gravel along the whole Sarenne section. Safety works on the D1091 near the Commères and Infernet tunnels until 30 October 2026, with alternating traffic and occasional closures (details on itinisere.fr). Nothing announced for 2027 so far.