Alto de las Portillas

Overview

Alto de las Portillas is a short, high-altitude effort that rewards a steady head rather than a heroic one. At 2.3 km long, it climbs from a start elevation of 1154 m to a summit of 1279 m — a net gain of 125 m. The average gradient sits at 5.35%, and the steepest ramp only nudges up to 5.86%, so this is a climb defined by consistency rather than by any single wall. As a category-4 ascent, it lands at the gentler end of the classification scale (the ladder runs HC, 1, 2, 3, 4), which makes it an ideal test of pacing discipline: there is nowhere to hide, but nothing here should ever blow you apart.

How the Gradient Unfolds

The story of this climb is the story of its remarkable evenness. With an average of 5.35% and a maximum of just 5.86%, the difference between the typical slope and the hardest pitch is barely over half a percent. That narrow band tells you almost everything: there are no sudden double-digit kickers to shatter your rhythm, and no long false-flat reprieves to let you coast. Instead, the road tilts up and holds that tilt for the full 2.3 km. Because the summit stands at 1279 m, the thinner air is the real variable here — the gradient never spikes, but altitude quietly taxes every pedal stroke, so what reads as a modest 125 m of net gain can feel a touch heavier than the numbers suggest.

Pacing Notes

On a climb this uniform, pacing is simply a matter of choosing a sustainable intensity and refusing to drift above it. A good anchor is your FTP: the power you can hold for roughly an hour. Because this ascent is short, you can comfortably ride slightly above threshold — but the flat gradient profile means every surge is paid back immediately in accumulated fatigue, so resist the urge to attack early ramps that look steeper than they are. Settle into a rhythm within the first few hundred metres and let the 5.35% average do the work. If you are unsure where your threshold sits, run the numbers through the FTP estimator before you ride, then translate that figure into a target you can hold from 1154 m all the way to the 1279 m summit.

Gearing

For a climb averaging 5.35% with a peak of 5.86%, most riders will be perfectly comfortable on a compact setup. A 34×32 bottom gear gives you enough range to spin the entire 2.3 km without grinding, keeping your cadence high and your legs fresh at altitude. If you prefer to sit and turn a lighter gear — or you are carrying fatigue from a longer day — a 34×34 offers a welcome extra margin without ever feeling like overkill on slopes this moderate. Either choice lets you prioritise cadence over torque, which is exactly the approach a steady climb like this rewards.

Summary

Alto de las Portillas is a compact, consistent category-4 climb: 2.3 km of near-uniform gradient that asks for smart pacing and a spinning cadence rather than raw power. The lack of steep ramps makes it approachable, while the 1279 m summit adds just enough altitude to keep you honest. Ride it evenly, gear light, and let the numbers guide you.

Length: 2.3 km
Average gradient: 5.35%
Max gradient: 5.86%
Start: 1154 m
Summit: 1279 m
Net gain: 125 m
Total ascent: 104 m
Category: 4