La Mégavalanche: the wildest MTB descent in the Alps

Picture several hundred mountain bikers lined up on a glacier, at 3,330 metres of altitude, one foot resting on the snow, waiting for the start signal. When it goes off, a human tide pours down the mountain in a cloud of powder before plunging towards the valley along the single-tracks. This is La Mégavalanche, one of the most legendary mountain bike races in the world, held every summer in the heart of the Oisans range, just a stone’s throw from our chalet in Oz-en-Oisans. Whether you dream of taking part or simply want to soak up the unique atmosphere of the event, here is everything you need to know.

A race born in 1995, now a legend

La Mégavalanche first came to life in 1995 on the slopes of Alpe d’Huez. Back then, the idea of a group start — like a mass ski race, but on mountain bikes — seemed completely insane. Thirty years on, it has become a fixture of the world downhill calendar, drawing riders from across the globe.

Its core principle has stayed true to the original spirit: a mass-start, meaning all competitors set off at the same time. Up to 1,500 participants can launch together, creating spectacular images and an electric tension on the start line. La Mégavalanche is not just an elite competition: it is a popular celebration of mountain biking, where seasoned amateurs and pros share the very same trails.

From the Pic Blanc glacier to the Allemont valley

The start is given at the top of the Pic Blanc glacier, at 3,330 metres of altitude. The first few metres are often ridden on snow, which adds a fearsome technical challenge: you have to keep your balance, manage grip and avoid chain crashes within the pack.

The race then drops onto mountain trails, alternating between scree, high pastures, forests and fast, flowing sections. In total, the course unfolds around 2,600 metres of vertical descent over nearly 22 kilometres, down to the valley of Allemont below. It is as much an endurance test as a riding one: you have to hold up physically over such a long descent while staying sharp through the most committing sections.

The event runs in two stages: qualifying rounds spread out the competitors, then comes the final — the highlight of the week, where the overall ranking is decided.

Mega Kids and e-Mégavalanche: a race for everyone

La Mégavalanche is not reserved for daredevils alone. The event offers several formats to welcome every kind of rider.

The Mega Kids lets the youngest riders taste the race atmosphere on a format suited to their level, in a safe setting. It is a great way to nurture the next generation and turn the event into a genuine family moment.

Meanwhile, the e-Mégavalanche opens the door to electric mountain bikes (e-MTB). This category is growing fast: it lets you handle the climb with assistance, then focus on the thrill and commitment of the descent. It is a wonderful way to experience the race for anyone who lacks the physical level of an elite racer.

The MTB summer in Oz-en-Oisans and Alpe d’Huez

La Mégavalanche is only the tip of the iceberg. All summer long, the Oz / Alpe d’Huez area turns into a vast playground for bike lovers. The Alpe d’Huez Bike Park, with its 260 km of trails, ranks among the largest in Europe: green runs for beginners, blues and reds to progress, blacks and committing single-tracks for experts, not to mention the modules of the freeride zone. Trail maps and lift openings are on the Alpe d’Huez tourist office website.

The Oz-en-Oisans lifts give direct access to the area, making it an ideal base for stacking up descents without wasting time. Between sessions, the calm and authentic village of Oz offers the perfect setting to recover. And if some in the group don’t ride, the hiking trails, high-altitude lakes and Oisans panoramas round out the stay beautifully.

To learn everything about the summer season, take a look at our page dedicated to summer in Oz.

The chalet: the ideal base camp for a group of riders

For a group coming to race or to cheer, logistics make all the difference. A large chalet in Oz-en-Oisans gives you room to live together, share meals and debrief the day’s descents around a big table.

Whether you’re aiming for the Pic Blanc start line or simply coming to feel the buzz as the pack rolls by, Oz-en-Oisans is the perfect place to stay. Book early: the Mégavalanche period is in high demand. To organise your stay, check July availability and send us a booking request.

Check availability for Mégavalanche week