An unforgettable loop in which you get to ride both sides of the mythical Alpe d’Huez.
Halfway up Alpe d’Huez you reach La Garde-en-Oisans and cut along a stunning vertiginous balcony road.
The route drops down to the Lac du Chambon before a beautifully quiet and tough climb to the Col de Sarenne.
From there you follow the little-known gem of a back route to Alpe d’Huez.
All metrics in this article are approximate.
Col De Sarenne loop highlights
The Auris balcony road (also known as the “Route de la Roche”), runs between La Garde-en-Oisans and Balme de Auris. It’s staggering. It’s perched on a cliff above the Romanche valley and has fabulous views over Bourg d’Oisans far below.
The first 40 seconds of the video above give you an idea of what it’s like, but you’ll have to ride it to appreciate the incredible views.
Avoid if you don’t like heights!
1. Bourg d’Oisans to Le Freney d’Oisans: 0-18.5 km
It’s an all-too-short, flat kilometre from Bourg d’Oisans to the base of Alpe d’Huez. The road quickly ramps up as you hit Alpe d’Huez’s infamous hairpins: it’s a 9.5% average gradient between the base and bend 16 in Garde en Oisans, where you turn off for the breathtaking balcony road.
From there it’s a twisty descent to Freney d’Oisans.
2. Le Freney d’Oisans to Col de Sarenne: 18.5-33.5 km
You cross the mighty Lac du Chambon and quickly turn off the main road into the Ferrand valley, on the tiny D25. Steel yourself for a tough ascent through four hairpins, up to the village of Mizoën. It’s then a straightish climb up through Clavans Le Bas until the hairpins kick in at about 27km, as you approach the summit of the Col de Sarenne (1,999m).
We did the route at dusk and had the road to ourselves. It was magical.
3. Col de Sarenne to Bourg d’Oisans: 33.5-57 km
From the summit of the Col de Sarenne, it’s a fantastic downhill run all the way home.
The 9 kilometres between Col de Sarenne and Alpe d’Huez village are remote and spectacular. Coming into Alpe d’Huez from the peaceful solitude of the Col de Sarenne feels pretty special as it’s so little known, compared to the route up the 21 hairpins from Bourg d’Oisans.
Your refuelling options are quite limited. Bourg d’Oisans and Alpe d’Huez village obviously have lots of options. Other than that, La Freney d’Oisans is probably your best bet (at the very least, there’s a petrol station and small shop there).
There are fountains with drinking water at various points along the route, including:
This ride starts and finishes in Bourg d’Oisans. You can find our accommodation suggestions in our guide for cyclists on where to stay in/near Alpe d’Huez.
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The Sarenne climb is lovely and the way to do the loop is to climb Sarenne rather than descend. It’s a bit gravelly and the road surface isn’t great for a fast descent.
Totally agree – beautiful road but much better to climb the Sarenne than descend it…