Puerto de Zafarraya

Overview

Puerto de Zafarraya is a long, steady category 1 test that rewards patience over punch. Over 16.7 km it climbs 864 m net, from a low start at 128 m to a summit at 992 m, at an average gradient of 5.19%. That number tells the honest story of this climb: it is rarely brutal, but it almost never lets you coast. With a max pitch of 11.16%, the hardest ramps are demanding without ever tipping into the leg-breaking territory of a hors catégorie giant. This is a climb of accumulation, where the effort is measured in the length of the road rather than any single wall.

How the Gradient Unfolds

The defining tension of Zafarraya is the gap between its 5.19% average and its 11.16% maximum. A near-6-percentage-point spread across 16.7 km means the road is not uniform. Long stretches sit at or slightly below the average, giving you rhythm and a chance to settle into a sustainable cadence, while occasional ramps rear up toward the double-digit maximum and force a hard reset of your effort. Because the total ascent of 870 m sits just 6 m above the 864 m net gain, there is almost no descending or false flat to recover on — nearly every metre gained stays gained. Read the road ahead: back off slightly before the steeper pitches so you have something in reserve when the gradient bites.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to your FTP and aim to hold a sustainable percentage of it across the full 16.7 km rather than surging early. A category 1 ascent of this duration can take well over an hour for many riders, so going into the red on the first steep ramp will cost you dearly by the summit at 992 m. If you are unsure of your threshold, run the numbers through the FTP estimator before you set your target power. Treat the 5.19% average as your baseline effort and spend a little extra only on the ramps toward 11.16%, then immediately settle back down. Consistent power, steady breathing, and a cadence you can hold for the duration will get you to the top faster than any heroics on the lower slopes.

Gearing

For a 16.7 km climb at 5.19% average with ramps to 11.16%, prioritise a low enough bailout gear to spin the steep sections. A compact chainring paired with a 34×32 will suit strong climbers who can keep the pedals turning under load. If you prefer to protect your legs across the full 864 m of climbing, or you are carrying fatigue, step up to a 34×34 for extra margin on the steepest pitches near the maximum gradient. The goal is to keep your cadence smooth rather than grinding a big gear — over this distance, spinning saves your legs for the summit.

Summary

Puerto de Zafarraya is a rhythm climber's ascent: long, steady, and honest, with just enough sting in its ramps to keep you focused. Pace it by your threshold, gear it to spin, and let the 16.7 km come to you.

Length: 16.7 km
Average gradient: 5.19%
Max gradient: 11.16%
Start: 128 m
Summit: 992 m
Net gain: 864 m
Total ascent: 870 m
Category: 1