Puerto del Portillón

Overview

Puerto del Portillón is a climb that rewards patience over panic. At 12 km long with an average gradient of just 3.31%, it reads on paper like a gentle drag — the kind of ascent you might expect to spin over without much drama. The numbers behind the average tell a more layered story. From a start elevation of 101 m, the road climbs to a summit at 498 m, a net gain of 397 m. Yet the total ascent is 652 m, meaning the road gives back roughly 255 m of elevation across false flats, dips, and shallow descents before delivering you to the top. That gap between net gain and total ascent is the single most important thing to understand about this climb.

How the Gradient Unfolds

A 3.31% average across 12 km is a soft number, and softness at the mean almost always means volatility underneath. This climb confirms it: the maximum gradient hits 18.49%, more than five times the average. That is a wall in the middle of what is otherwise a rolling road. The 652 m of total ascent stacked against 397 m of net gain tells you the profile pitches up, eases off, and even drops before rising again. Expect stretches that barely register as climbing punctuated by at least one sharp, unforgiving ramp approaching 18.49%. The gentle mean lulls you; the ramps punish anyone who arrives at them already redlined.

Pacing Notes

The discipline here is restraint on the easy kilometres. Because the average is only 3.31%, it is tempting to push hard on the shallow sections — but that steepest 18.49% pitch will find you out if you have spent yourself early. Anchor your effort to your FTP and let the shallow portions sit comfortably below threshold, saving matches for the ramp. If you do not know your threshold number, run the numbers through the FTP estimator before you tackle the climb. Treat the descents and false flats within the 12 km as active recovery, then commit hard and briefly through the wall.

Gearing

Do not let the modest average gradient talk you out of climbing gears. A 34×32 is the sensible baseline for tackling the 18.49% ramp without cross-chaining into a grind, and it will keep your cadence honest through the steep pitch. If you climb on the heavier side, ride primarily at endurance pace, or simply want more margin, step up to a 34×34 — the extra sprocket costs nothing on the 3.31% sections and buys real breathing room where the road kicks toward 18.49%. As a category 3 climb, Portillón sits below the HC and category 1 monsters, but its gearing demand is set by that single steep ramp, not by its friendly mean.

Summary

Puerto del Portillón is a study in why averages deceive. Twelve kilometres at 3.31% sounds trivial, but the 18.49% maximum and the 652 m of total ascent against just 397 m of net gain reveal a rolling, spiky road that punishes the impatient. Pace the shallow sections, respect the wall, and gear for the ramp rather than the mean.

Length: 12 km
Average gradient: 3.31%
Max gradient: 18.49%
Start: 101 m
Summit: 498 m
Net gain: 397 m
Total ascent: 652 m
Category: 3