Les 2 Alpes via the Chambon dam
Road cycling
- Distance
- 24.8 km
- Elevation
- 1,050 m
- Est. time
- 1 h 30
- Power
- 220 W
- Max altitude
- 1,663 m
- Avg gradient
- 3.8%
The climb: 9.8 km averaging 6.2%, 10.7% at its steepest, 608 m of elevation gain, from the Chambon dam to the resort.
Time and power estimated for a 75 kg rider at 220 W, climbing without stopping. Route from OpenStreetMap, altitudes from Copernicus.
Leave Bourg-d'Oisans on the D1091 and head up the Romanche valley: the Commères ramp, a short descent towards Le Freney-d'Oisans, then the climb back up to the Chambon dam, with four lit tunnels along the way. At the dam, turn right onto the D213 and the real climb begins, on a wide road with numbered hairpins, just like Alpe d'Huez. A flatter stretch at Mont-de-Lans, Lac du Chambon below, then the resort. Marco Pantani won the Tour stage here in 1998, Santiago Botero in 2002.
- Tour stage finish in 1998 (Pantani) and 2002 (Botero)
- A memorial to Marco Pantani awaits at the top
- Numbered hairpins and views over Lac du Chambon
- Summer
- Road rideable from May to October, weather permitting.
- Winter
- Closed in winter · reopens in May
Set off early, before the traffic builds on the D1091 and the D213, with a bright gilet and a rear light for the tunnels. For the way down, the tourist office suggests the minor road via Bons and Le Ponteil, quieter but narrow and rough in places; otherwise, take the D213 back down.
Four lit tunnels on the D1091 between Le Clapier and the dam (Commères, Infernet, Clos du Freney and Chambon dam), so make sure you're clearly visible. Heavy summer traffic on the D1091, the Grenoble-Briançon route, and on the D213. Safety works near the Commères and Infernet tunnels until 30 October 2026: alternating traffic, and a full closure on 30 October from 9am to 3pm between Le Clapier and Rivoire. Nothing announced for 2027 so far, so check itinisere.fr before you set off.