Some climbs are just long. Others are legends: the places where the Giro d'Italia or the Tour de France was won, where ramps well beyond 15% cut into the mountain, and where every amateur wants to stand at the top once in their life. This overview covers the most famous Alpine passes for road cyclists – with length, elevation gain, gradient, number of hairpins and the story behind each one.
How to read the numbers
Five figures describe a climb:
- Length – distance from the foot to the summit.
- Elevation gain – the total metres climbed.
- Average gradient – elevation divided by length. Misleading: the Col de l'Iseran averages just 4.1% but runs almost 48 km.
- Maximum gradient – the steepest ramp. Up to 21% on the Stelvio.
- Hairpins – the switchbacks. Their number has become the signature of several passes.
Italy
The brutality of the Italian Alps: narrow lanes, savage ramps, Giro mythology.
Stelvio Pass – 2,757 m
21.7 km, 1,580 m of climbing, avg 7.4%, ramps to 21% – and 48 numbered hairpins stacked like a staircase up the eastern wall. The second-highest paved pass in the Alps, open since 1825, and for many the most beautiful climb there is.
Passo del Mortirolo – 1,852 m
Just 12.4 km, but averaging 10.5% with ramps to 18%. No views, no respite – since the Giro first used it in 1990, the climb from Mazzo has been rated the hardest in Italy.
Passo di Gavia – 2,621 m
17.3 km, avg 8.0%, 16% in places, with a narrow, unguarded plateau at the top. The Gavia became famous through the 1988 blizzard stage of the Giro.
Passo Pordoi – 2,239 m
From Arabba, 9.2 km at a steady avg 6.9% with 33 hairpins – the most rhythmic climb of the Sellaronda and the pass the Giro has crossed most often.
France
Wide switchbacks, Tour history – and in the Ventoux, a mountain in a class of its own.
Col du Galibier – 2,642 m
From Valloire, 17.7 km, 1,245 m of climbing, avg 6.9%. On the Tour de France route since 1911 and usually its highest point – often linked with the Col du Télégraphe right before it.
Col du Tourmalet – 2,115 m
19.0 km from Luz-Saint-Sauveur, 1,404 m of climbing, avg 7.4%. The most frequently climbed pass in Tour history – the roof of the Pyrenees, first raced in 1910.
Mont Ventoux – 1,909 m
From Bédoin, 21.4 km, 1,610 m of climbing, avg 7.5%, not a single flat metre. After the forest of Saint-Estève the infamous lunar landscape begins – wind, heat and no shelter. The «Giant of Provence».
Alpe d'Huez – 1,860 m
13.8 km, avg 8.1%, 21 numbered hairpins – each bearing the name of a stage winner. A Tour finish since 1952 and the loudest summit finish in cycling.
Col de l'Iseran – 2,764 m
From Bourg-Saint-Maurice, 47.5 km at just avg 4.1% – the highest paved pass in the Alps. Not a steep climb but a long road into thin air.
Which pass is the hardest?
Depends on what breaks you. Pure steepness: the Mortirolo at avg 10.5%. Length plus ramps plus altitude: the Stelvio, 48 hairpins and 21% pitches above 2,700 m. The mind: the Ventoux – no flat section to recover, plus wind and heat in the scree desert.
Best time to go and how to prepare
Most high passes are only clear of snow from June to late September; the Gavia and Iseran often open late. Start early – afternoons bring thunderstorms, and on the Ventoux the Mistral picks up. For the steep climbs, fit a compact chainset (34) with a 30- to 34-tooth sprocket. Record the climb with Strava, Garmin or Wahoo – you'll want the GPX file later.
Put your pass on the wall
If you've ridden one of these climbs, you can keep it as a poster – the route drawn from above, plus distance, elevation gain, hairpins and, optionally, your name and the date you rode it. The switchback monsters like the Stelvio (48) or Alpe d'Huez (21) make a pattern all their own as a single line – an elevation profile never could. Every pass in this article is available in the pass series.
Got another climb in your legs – one that isn't listed here? Upload your GPX file and turn it into your own poster.
Stelvio, Mortirolo or the hill outside your front door: the mountain stays on the wall.