Alto de Ño León

Overview

Alto de Ño León is a genuine hors-catégorie (HC) giant. At 39.1 km it is long enough to be a day's ride on its own, and it starts almost at sea level — just 7 m — before topping out at 2081 m. That works out to 2074 m of net elevation gain, with 2207 m of total ascent once the small dips and false flats are counted in. The 133 m gap between net gain and total ascent tells you this is not a perfectly monotonic ramp: there are stretches where the road gives a little back before demanding it again.

The headline average is 5.31%, which sounds civil until you remember it is sustained across 39.1 km. There is no long recovery valley here that can quietly flatter the numbers — a category rating of HC on a climb this length means the effort is measured in hours, not minutes.

How the Gradient Unfolds

With a 5.31% average and a 13.01% maximum, Ño León is a climb of contrasts. The overall slope is moderate, but the pitches that reach toward 13.01% are more than double the average — those are the sections that will spike your heart rate and force you out of rhythm. Because the total ascent (2207 m) exceeds the net gain (2074 m) by 133 m, expect the profile to undulate: short descents and flatter shelves that interrupt the climbing and let the gradient reset before ramping up again. Treat every easing not as rest but as a chance to recover for the next steep kick.

Pacing Notes

On a climb of this duration, pacing is everything. The smartest approach is to ride the long 5.31% sections just below your sustainable threshold and reserve headroom for the pitches nearing 13.01%. Anchor your effort to your FTP: aim to sit comfortably under it on the moderate grades so you have something left when the road bites. If you do not know your number, use the FTP estimator to set a realistic target before you start. Over 39.1 km, going even slightly too hard early compounds badly — the summit at 2081 m is a long way from the 7 m start, and there is no shortcut back down.

Gearing

Gear for the steep pitches, not the average. The 13.01% maximum is where compact setups earn their keep. A 34×32 is the sensible baseline for most riders tackling an HC climb of this length, giving you a low enough ratio to keep cadence up when the grade doubles the average. If you tend to grind, or you want insurance for 39.1 km of accumulated fatigue, step up to a 34×34 — that extra range keeps your legs spinning rather than straining on the ramps toward 13.01%, and protects your knees over the full 2074 m of gain.

Summary

Alto de Ño León is a rare thing: an HC climb that is as much about endurance as gradient. Nearly 40 km from a 7 m base to a 2081 m summit, with punchy pitches to keep it honest, it rewards patience, sensible gearing, and disciplined pacing.

Length: 39.1 km
Average gradient: 5.31%
Max gradient: 13.01%
Start: 7 m
Summit: 2081 m
Net gain: 2074 m
Total ascent: 2207 m
Category: HC