Alto de Escoya

Overview

Alto de Escoya is a genuine giant. At 45.9 km with an average gradient of 5.25%, it is the kind of ascent that measures endurance more than raw power. The road begins at 869 m and tops out at 3279 m, a net elevation gain of 2410 m spread across nearly forty-six kilometres of continuous climbing. Its hors catégorie (HC) rating is well earned: the sheer duration, the thin air near the summit, and the 2441 m of total ascent combine to make this one of the most demanding climbs you can attempt.

The moderate-looking average of 5.25% hides the reality of the effort. Over this distance, a steady grade becomes a grinding, hour-plus test, and the max gradient of 9.83% guarantees at least one section that forces you out of any comfortable rhythm.

How the Gradient Unfolds

The defining feature of Escoya is its length, not its steepness. With an average of 5.25% and a peak of 9.83%, the climb never becomes a wall, but it also never truly relents across its 45.9 km. The gap between total ascent (2441 m) and net gain (2410 m) is small — just 31 m — which tells you this is an overwhelmingly uphill road with almost no descending or false-flat recovery built in.

Expect long, sustained ramps at or near the average, punctuated by steeper pitches climbing toward that 9.83% maximum. Because there is so little respite, the gradient's real story is accumulation: every kilometre adds to a load that peaks at 3279 m, where altitude thins your effort further.

Pacing Notes

On a climb this long, discipline is everything. The single biggest mistake is riding the early ramps too hard; with 45.9 km ahead, minutes saved at the bottom are paid back with interest near the top.

Anchor your effort to your FTP. For a sustained HC effort of this duration, most riders should sit comfortably below threshold, holding a percentage they can defend for well over an hour. If you do not know your number, estimate it first with the FTP estimator, then set a ceiling and refuse to exceed it on the steeper 9.83% pitches.

As you approach 3279 m, altitude reduces available power. Budget for that: the final stretch will feel harder than the gradient suggests, so keep a reserve for the last kilometres rather than emptying the tank early.

Gearing

For a 45.9 km HC climb topping out at 3279 m, gear low and protect your legs. A compact 34-tooth inner chainring paired with a wide-range cassette is the sensible baseline. A 34×32 combination will serve stronger climbers on the sustained 5.25% sections, but given the length and the 9.83% maximum, most riders will be grateful for 34×34 when altitude and fatigue stack up near the summit.

The extra range costs almost nothing on a climb where you will never want a bigger gear. Choose the easier ratio and spin — cadence preserves your legs across a 2410 m net gain far better than grinding does.

Summary

Alto de Escoya is an endurance monument: 45.9 km of climbing, 2410 m of net gain, and a summit at 3279 m that demands patience, smart pacing, and forgiving gears. Respect its length, ride within your FTP, and it becomes one of the most rewarding HC ascents you can complete.

Length: 45.9 km
Average gradient: 5.25%
Max gradient: 9.83%
Start: 869 m
Summit: 3279 m
Net gain: 2410 m
Total ascent: 2441 m
Category: HC