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Big Ride: Col de l'Iseran

1 May 2018

Words Trevor Ward  Photography Juan Trujillo Andrades

The Col de l’Iseran lures cyclists on a relentless, zig-zagging ascent into the heavens, rising high above ski lifts, through wreaths of wispy cloud, and past pools of snow lying like scoops of ice cream in shaded craters, until even the wings of paragliders and eagles can be seen circling in the valley below.

So perhaps it is only fitting that when I finally edge over its celestial summit, gasping in the oxygen-starved air, I glimpse the face of God. Or, at least, the kindly smile of one of His ambassadors on Earth.

At the top of this colossal peak in the French Alps lies the pretty stone and slate Chapelle Notre-Dame de Toute-Prudence (the Chapel of Our Lady of All Prudence to you and me) and standing serenely in its doorway as I clear the summit is a priest dressed in black robes.

To my surprise I see an ornate sword wrapped in a scabbard, propped up against the entrance. Built in 1939, two years after the road here was completed, the chapel receives voluntary support from the Knights of the Holy Sepulchre, a Roman Catholic order that dates back to the end of the First Crusade in 1099.

Excessive childhood viewings of Indiana Jones and the Last Crusade have left me wondering if I will now be required to complete some epic final trials of courage and faith before being allowed to officially complete the ascent.

As the highest pass (and second highest paved road) in the Alps, the 2,770m Col d’Iseran is, after all, the Holy Grail of French cycling climbs.

The priest rings a bell and the metallic clang echoes around the surrounding mountains in a spine-tingling demonstration of natural acoustics no human-built theatre could hope to match.

The bell is, of course, nothing to do with me or the other two-wheeled pilgrims I can see who have stopped for a drink having survived the test of faith and fitness that is the Iseran, but it is nevertheless an enchanting way to finish the climb.

I nod to the priest, remove my helmet and wander into the cool depths of the chapel where flickering candles light up the altar. After the heat and toil of the climb, it’s a welcome pocket of peace.

My laboured breathing – which had progressively become shorter and more ragged the higher I climbed – sounds even shakier in the silence of the chapel. I later discover that some cyclists and motorcyclists complete pilgrimages here in summer to have their bikes blessed for good luck. At this altitude, any help is welcome.

Le Big One

The lung-busting Col de l’Iseran, which is located close to the French-Italian border in the western Alps, has featured in the Tour de France seven times.

Its inaugural appearance came in 1938 when Belgian Felicien Vervaecke made it to the top first, while its most recent showing was in 2007 when Ukrainian Yaroslav Popovich led the peloton over the top. Its peak is imposing and unpredictable. At the 1996 edition of the Tour the stage that was due to cross the Iseran had to be annulled because of unseasonable snow.

Owing to the Iseran’s altitude, July and August are still the most reliable months to cycle here, according to Edouard Rolland, a local cycling guide who has joined me for today’s ride.

He says the col is only accessible during the summer because in winter it forms part of the expansive Espace Killy ski area, named after local hero and triple Olympic ski champion Jean-Claude Killy. Arrive any later in the year and you’ll need to swap your wheels for skis.

Our ascent begins in the stylish ski resort of Val d’Isère in the Tarentaise Valley. The town clings to the powder blue water of the Isère river, dwarfed on all sides by peaks adorned with dangling chairlifts and dense pine forests.

Over winter the resort’s wooden chalets are crammed with skiers and snowboarders, but in summer the town offers a tranquil base from which cyclists can explore the collection of cols nearby.

And because this is a well established ski destination, when you return to the town you can enjoy excellent food (including chocolate pudding at L’Atelier d’Edmond, which is run by the double Michelin-starred chef Benoit Vidal) and indulge in post-ride recovery sessions WorldTour pros would be jealous of (the Centre Aquasportif has pools, saunas, massage jets and even aquabikes).

Val d’Isère is itself 1,847m above sea level so to get to the summit of the Iseran involves 923m of ascent over 17 high-altitude kilometres. Technically, the climb starts further north in Bourg St Maurice, offering an epic 48km and 1,955m of ascent, but the road is guarded by eight long, dark tunnels.

Spinning downhill to Bourg St Maurice would enable you to sweep happily through the tunnels at speed, but it would be no fun to inch through them slowly on an ascent in the other direction. For that reason, we start in Val d’Isère, from where we can launch a direct assault on the safer and more spectacular upper flanks of the Iseran.

Natural high

After a leg-toasting dash through the Tarentaise valley, we pass the immaculate mountain village of Fornet, where almost all of the chalets are built from traditional Savoyard wood and local stone.

Soon the first of the yellow and white road markers that show the distance to the summit appears up ahead. At the arched St Charles bridge, the road swings right over the Isère river and we begin to climb in earnest.

Slithering glaciers shimmer high above us in the sunshine and waterfalls gush down the side of the mountain. We’re now riding through the Vanoise National Park, which was the first French national park ever created. In the summer, it’s a pristine landscape of lush mountain meadows and grey peaks brought to life by bearded vultures, scuttling marmots and roaring motorbikes.

We’re above the tree line already so every view is expansive. Edouard points out the twinkling white pyramid of Tignes looming behind us.

The climb averages 6% and rarely tops 8% so it’s easy to slip into a gentle rhythm. But as the altitude soars and the oxygen in the air drains away, breathing becomes harder and maintaining the same power output becomes impossible.

Edouard and I have been chatting happily but above 2,300m my conversation is reduced to monosyllabic gasps and grunts. At the 2,770m altitude of the summit, the aerobic power of an unacclimatised athlete can dip by as much as  20%.

We climb through an Alpine meadow dotted with meandering streams and isolated shepherds’ huts. This region has hosted multiple Ski World Cup events and as we climb higher the road dips under the cables of ski lifts. Near the summit we pass a lake used to feed the snow cannons.

As we approach the top we pedal into a stark landscape festooned with grey: the tumbling scree, the giant rocks, the jagged piles of slate, and even the road itself all merge into a single silvery scene, as if the mountain has been coated in ash.

On arrival at the col, the priest with his sword isn’t the only unexpected sight. We also meet a 78-year-old French cyclist who has completed the climb from Val d’Isère in just under an hour.

Some touring motorcyclists are using a selfie stick to take a group photo, and two shirtless roller-skiers arrive at the top, their chests heaving behind their heart rate straps. I demolish a pain aux raisin and pull on a gilet for the descent.

Maurienne, please

The road we have been riding connects the Tarentaise valley around Val d’Isère with the Maurienne valley that surrounds the Arc River and the town of Bonneval-sur-Arc.

Between the Iseran summit and Bonneval lies a descent with a pacy 7.3% average gradient and several sections at 10%, dropping us 977m by the time we reach the bottom.

On this side of the mountain the grey of the rocks and the green of the meadows are softened and bleached, as if we’re plummeting into a watercolour painting.

Mountains rise and fall ahead of us, like the waves of a frozen ocean, all the way to the horizon. At intervals we glimpse the triangular peak of Mont Blanc hiding in wisps of cloud.

We dive into Bonneval, a beautiful mountain village of stone houses, which offers a moment of level ground before we point downwards once more and begin the 20km dash through the Maurienne valley to the town of Lanslebourg-Mont-Cenis.

We zip over steel bridges painted blue and green. At one point we team up with a Dutch woman who had been toiling alone on her bike against the headwinds. Before long we arrive in Lanslebourg, where we sit in the shade and eat baguettes stuffed with salami and cheese, and slices of pizza bread overflowing with sundried tomatoes.

From here we start our second big climb of the day, to the 2,081m Col du Mont Cenis. It is a lesser-known but gritty hors catégorie climb that has appeared in the Tour de France five times, the most recent being in 1999. Close to the Italian border, it also featured in the 2013 Giro d’Italia.

This historic pass, which marks the boundary between the Cottian and Graian Alps, has been used for centuries. The Carthaginian general Hannibal is believed to have passed here on his famous elephant crossing of the Alps in 218BC.

Charlemagne, the King of the Francs, crossed it with his army (not of elephants) in 773. Medieval pilgrims used it on their way to Rome. Then Napoleon Bonaparte constructed the road here in 1810 to allow carts and carriages to pass over.

I had expected the climb to be the easier of the day’s two ascents. I was mistaken. The Mont Cenis rises 682m over 9.8km, with an average gradient of 7% and bursts of 10%. In the early afternoon heat, however, it’s a gruelling ascent, although thankfully the shade of the forest makes the temperature more bearable.

The road is a sinister blend of steep straights and wide hairpins and in the last kilometre, as the road straightens out, we face a punishing headwind that seems determined to swipe us back downhill from whence we came.

High altitude

And although this entire route features less than 2,500m of climbing, most of it is at high altitude so it’s much tougher than the profile suggests.

At the summit we’re welcomed by the glistening expanse of the Lac du Mont Cenis. Surrounded by pointed spires of rock and glowing bright blue in the sunshine, it’s a scene more evocative of Patagonia than the Alps.

The peaks of the 3,610m Pointe de Ronce and the 3,478m Mont Lamet stand guard over the lake and more than 700 different types of flowers light up its shoreline.

In the 1961 edition of the Tour de France, French riders Manuel Busto and Guy Ignolin arrived here with a commanding 25-minute lead and Busto took the opportunity to dive into the lake to cool down.

Ignolin did the gentlemanly thing and waited for him, before outsprinting his soggy countryman to the line in Turin. Today we meet a cyclist who says he is cycling from Geneva to the south of Italy. He’s wearing running trainers and has a track pump lashed to the back of his bike. I wish him luck as he continues slowly on his 1,500km journey.

At the summit we’re met by an even more improbable sight than the chapel that sits atop the Iseran: a giant stone pyramid. Apparently, Napoleon wanted to build a pyramid here to commemorate his Egyptian campaigns, but he died before he could realise his ambition, so in 1968 the energy company EDF, which manages the Cenis reservoir and dam, duly obliged.

The structure sits equidistant between Paris and Rome and contains a chapel and a museum with information on the colourful history of the pass.

At the end of the lake is the stone-covered dam that marks the start of our descent. Before we gather speed, however, we take a moment to explore an eerie abandoned village that lies in the shadow of the dam wall, its houses now crumbling since the residents have moved away.

Italian flair

The descent from Mont Cenis is a scintillating dash along a snaking road dotted with white road markers and flanked by rocks covered in bright green moss the colour of kiwi fruit. Only a thin wire stands between the road and the drop below. At some point over the last few kilometres we crossed the invisible border between France and Italy.

Further down, a deep drainage gully sits between the road and a wall of rock. I don’t fancy skidding into it so I rein in my speed. Halfway down I see the crumpled remains of a van that wasn’t so fortunate.

We eventually roll into the Italian town of Susa at the foot of the Cottian Alps. This atmospheric old town is filled with Roman ruins, narrow passages, shuttered apartments and crumbling old walls.

It’s the end of our route and we have a long journey by car to get us back to our hotel in Val d’Isère, but seeing as we are in Italy it’s only right that we linger a while and grab some gelato and espressos on the terrace of a cafe before we leave.

After a long day in which we reached two summits above 2,000m, viewed pyramids and mountain chapels, followed in the footsteps of Roman emperors and French kings, and crossed the highest pass in the Alps, it’s a welcome reward.


Dare to Isère?

How to tackle the highest pass in the Alps

To download this route go to From Val d’Isère, head southeast on the D902 and go all the way up and over the Col d’Iseran.

At Bonneval-sur-Arc you can take a 4km climb to the pretty village of L’Ecot before returning and heading south on the D902 once more, travelling through the Maurienne valley until you reach Lanslebourg-Mont-Cenis.

From here, take a left onto the D1006 and head up to the Col du Mont Cenis. Follow the D1006 past the lake and the dam before continuing south on the descent. Cross the border into Italy on the SS25 and continue to Susa.


The rider’s ride

Trek Émonda SLR 8 Disc, £6,000,

This is a bike that looks great and performs even better. It’s marketed as Trek’s lightest ever production road line, with every detail from the frame design to the component choice carefully selected to give you a light and breezy uphill ride – welcome news on the 2,770m Cold de l’Iseran.

Even gear shifts are energy-efficient thanks to the flawless Shimano Dura-Ace Di2 groupset, which whirs pleasingly with every touch of the button.

The hydraulic disc brakes injected a welcome dose of reliability and peace of mind into my Alpine adventure. Even on the steepest of descents they were reassuringly firm and responsive, while still allowing for the subtle changes of pace needed at the approach of swirling hairpins.

This is a fast, light and responsive ride, perfect for tackling the very highest mountains in Europe.


How we did it


We flew with EasyJet, which offers flights from London to Geneva or Lyon costing from £60 return. Bike carriage costs from £80 return when booked in advance.

Our support vehicle for the ride was kindly provided by SnowDrone (, which also offers private airport transfers.


We stayed at the three-star Hotel La Tovière in Val d’Isère ( The hotel is bike-friendly, with storage rooms for bikes, a sauna and steam room for your recovery, and an excellent restaurant. Rooms cost from €59 (not including breakfast).


We were guided by Edouard Rolland from On Gravity ( Guided tours cost from €100 per person per day and include bike and helmet hire.


Cyclist was a guest of the Val d’Isère tourism board ( Many thanks to Rosie, Kerstin and Cecile for their help in organising the trip.