From Biescas (2,795 ft / 852 m) to the Puerto del Portalet (5,886 ft / 1,794 m), on the French border, it’s 17 miles (27.3 km) at an average of 3.4%: 3,091 ft (942 m) of climbing on the A-136. Altimetrias.net gives 27.34 km and 3,091 ft (942 m); Climbfinder, 16.8 miles (27 km) and 3,166 ft (965 m); and CyclingCols, 16.8 miles (27.1 km) and 3,261 ft (994 m), with a maximum of 8.1%. The difference in elevation gain comes from the short descents along the valley.
What the climb is like
It’s a long, gentle climb, more valley than mountain until the final section. You leave Biescas and head up the Tena valley, through Escarrilla and past the turnoff for Sallent de Gállego. The road is excellent: about 33 ft (10 m) wide, with a shoulder so you can ride clear of the cars, good signage and several stretches with a slow-vehicle lane. The grade is gentle almost the whole way, with a few kicks of 6-8%; CyclingCols puts the hardest kilometer at 7.1%. Past the Formigal ski resort the road climbs through open terrain to the pass, surrounded by the border mountains.
History
The Portalet has featured in the Vuelta a España and the Tour de France. According to CyclingCols, riders first over the top include Peter De Clercq (1991 Tour), Julio César Cadena (1992 Vuelta), Piotr Ugrumov (1995 Vuelta), Joan Horrach (2003 Vuelta) and Romain Bardet (2023 Vuelta). Every June the Alto Gállego area hosts the Quebrantahuesos gran fondo.
When to go, water and traffic
June to October. Snow arrives in November and the pass can close in winter. There’s no shade on the whole climb, so in summer the heat bites on the lower section. There are fountains in Escarrilla and at a picnic area just after it. Traffic is moderate, with more cars in summer and during ski season, but the shoulder makes it feel very safe.
What gearing to use
At 3 W/kg (watts per kilo of body weight) and 159 lb (72 kg) you’ll average about 12.4 mph (20 km/h): with a 50x28 that’s about 90 rpm, and with a compact 34x25 you’ll have plenty to spare. The hard part here isn’t the gradient but holding your pace for more than an hour. Check your combinations in the gear calculator.
Tips
- Ride the valley in a group if you can: into a headwind the lower section drags on.
- Bring a windbreaker: at the top, close to 5,900 ft (1,800 m), it’s cool and the descent is long.
- From the pass you can drop into France and climb the Aubisque, or come back down the same valley.
Frequently asked questions
How long does it take to climb the Portalet from Biescas?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 1 h 20 min at 3 W/kg (216 W), 1 h 32 min at 2.5 W/kg and 1 h 05 min at 4 W/kg. Work out your own time with your weight and power in the calculator on this page.
Which side of the Portalet is harder?
The French side, from the Ossau valley: CyclingCols measures it at 17.6 miles (28.4 km) and 4,265 ft (1,300 m) at 4.5%. The Spanish side, from Biescas, has less climbing and an average of only 3.4%.
Is there water on the climb?
Yes: in Escarrilla and at a picnic area just after it. Also in the valley villages, such as Biescas or Sallent de Gállego, and there are bars in Formigal.