From La Chambre (1,483 ft / 452 m, at the D927 junction) to the Col du Glandon (6,312 ft / 1,924 m) it’s 13.2 miles (21.3 km) at an average of 6.9% with 4,829 ft (1,472 m) of climbing. The average doesn’t tell the whole story: there’s a rest halfway up and a finish that’s much harder than the start.
What the climb is like
- Km 0 to 9 (miles 0-5.6). Almost constant grades of 7-8% up the Villards valley, through Saint-Alban-des-Villards. There’s shade at times.
- Km 9 to 11 (miles 5.6-6.8). The breather: an almost flat section, with even a short descent, at Saint-Colomban-des-Villards. Eat and drink here.
- Km 11 to 18 (miles 6.8-11.2). The road climbs again at 7-10% through meadows and pastures, with a string of bends at the Alpage de l’Échet.
- The last 1.9 miles (3 km). The worst comes at the end: kilometers averaging 10.5, 11 and 11.5%, with 12% sections, with the pass already in sight.
A note on the numbers
Wikipedia and cols-cyclisme give 13.2 miles (21.3 km) and 4,829 ft (1,472 m) (6.9%); Climbfinder, 13.0 miles (20.9 km) and 4,836 ft (1,474 m) (7%). CyclingCols measures it from nearby Saint-Étienne-de-Cuines: 12.3 miles (19.8 km) and 4,728 ft (1,441 m) at 7.2%.
History
The Glandon road opened in 1898 and wasn’t joined to the Croix de Fer road until 1912. The Tour de France first crossed it in 1947, with Edward Klabiński leading, and has used it often since, sometimes without a KOM, as the way to the Croix de Fer. Riders first over the top include Richard Virenque (1994 and 1997), Romain Bardet (2015) and Lenny Martinez (2025), on the stage that finished on the Loze.
When to go, water and traffic
It’s closed in winter, usually from November to mid-May. Traffic is moderate. There are fountains and services in Saint-Alban and Saint-Colomban; at the top, a hut with a bar in season. If you ride the Alpe d’Huez loop or La Marmotte, this is the other side of its route.
What gearing to use
With the finish in mind, bring a 34x30 or 34x32. At 3 W/kg and 159 lb (72 kg), you’ll ride about 5 mph (8 km/h) on 11%: that’s about 62 rpm in a 34x32 and only 54 in a 34x28. Check it in the gear calculator.
Frequently asked questions
How long does it take to climb the Glandon from La Chambre?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 1 h 43 min at 3 W/kg (216 W), 2 h 02 min at 2.5 W/kg and 1 h 19 min at 4 W/kg. Work out your own time with your weight and power in the calculator on this page.
Where is the hardest part of the Glandon?
In the last 1.2-1.9 miles (2-3 km), which are above 10% with sections of 11-12%. Before that there's an almost flat breather at Saint-Colomban-des-Villards, around halfway.
When is the Col du Glandon open?
According to Wikipedia, it's usually closed from early November to mid-May because of snow.
What's the difference between the Glandon and the Croix de Fer?
They share almost the whole climb from La Chambre. Just before the top of the Glandon, the road branches off and continues to the Croix de Fer (6,781 ft / 2,067 m); from this side, Wikipedia gives 14.1 miles (22.7 km) at 7% to the Croix de Fer.