Puerto de los Portillinos

Overview

Puerto de los Portillinos is an HC-category climb in Spain, running 10km from a start elevation of 935m to a summit at 1871m. Over that distance it delivers a net elevation gain of 936m at an average gradient of 9.34% — steep enough on paper to sit firmly among the hardest categorized ascents you can ride.

The average, however, undersells the work. Net gain is 936m, but total ascent is 1349m. That 413m difference is climbing you do twice: the road pitches up, drops back, and pitches up again. Every metre of descent inside the climb is elevation you have to reclaim, which means the effort is heavier and less rhythmic than a smooth 9.34% grade would suggest. Expect to lose your cadence and re-find it repeatedly rather than settle into one gear.

How the Gradient Unfolds

A 9.34% average across an undulating profile means the hard sections are considerably harder than the number implies — the flatter and downhill stretches drag the average down, so the true climbing ramps bite well above 9.34%.

• Short recovery or false-flat sections where the road eases or briefly descends — use them, don't attack them.
• Repeated short climbs stacked back to back, the source of the 413m of extra ascent beyond the net gain.
• The steepest single ramp, where the grade spikes sharply above the average — the pitch that decides whether you finish strong or blow up.

Pacing Notes

On a smooth climb you can chase even speed. Here, don't — the undulation makes even speed a trap, because holding pace on the steep ramps forces spikes well over your ceiling. Target even effort instead: hold steady power up the ramps and let your speed rise on the flatter sections rather than surging.

Anchor that effort to your sustainable power output and keep the ramps close to it, saving any surges for the final kilometre. If you don't know your number, run the FTP estimator first — pacing a 10km HC climb blind is how you crack before the summit.

Gearing

The climbing ramps here run steep, and steep pitches punish tall gearing. Fit a compact or sub-compact chainset paired with a wide-range cassette — think 34×32 or 34×34 — so you can keep cadence up when the grade spikes rather than grinding it out at 40rpm. On a 936m net gain with 1349m of total ascent, spinning a low gear is the difference between arriving fresh and arriving cooked. Check your setup before the ride; you don't want to discover you're over-geared on the first ramp.

Summary

• Length: 10 km
• Average gradient: 9.34%
• Maximum gradient: 29.39%
• Net elevation gain: 936 m
• Total ascent: 1349 m
• Category: HC

Puerto de los Portillinos is a 10km HC test where the 413m gap between net gain and total ascent, not the average gradient, defines the day. Pace to even effort, gear low, and respect the ramps.