Alto de Curíes

Overview

Alto de Curíes is a hors catégorie climb that earns its HC label the honest way: length, gradient, and thin air stacked on top of one another. Over 15.2 km the road lifts you from 1924 m at the base to 3228 m at the summit, a net gain of 1304 m. The average gradient sits at a punishing 8.58%, and there is very little on this mountain that resembles rest. This is not a climb you outsmart with tactics — it is one you survive by respecting the number on your power meter.

How the Gradient Unfolds

An 8.58% average across 15.2 km tells you the climb almost never eases. Sustained double-digit ramps are the norm rather than the exception, and the pitch spikes to a savage 24.52% at its steepest. A wall like that mid-climb is not something you power over on feel; if you hit it out of position or in too big a gear, it can end your day. Note also the gap between total ascent (1256 m) and net elevation gain (1304 m): the two figures are close, which means the road climbs relentlessly with only the faintest false-flat relief. Expect the mountain to keep tilting upward from bottom to top, with the altitude at 3228 m quietly sapping whatever you have left near the summit.

Pacing Notes

On a climb this long and this steep, pacing is everything. Your FTP is the single most useful number you can bring to Curíes — ride the lower slopes just under threshold and treat the 24.52% ramp as the moment you spend your reserves, not the moment you find yourself in trouble. Because the summit sits at 3228 m, thin air will trim your sustainable power the higher you climb, so plan to hold something back for the final kilometres rather than emptying the tank early. If you are unsure what wattage you can actually sustain for a 15.2 km effort, run the numbers through the FTP estimator before you commit to a target and build your climb around it.

Gearing

Do not under-gear this mountain. With an 8.58% average and a 24.52% maximum, most riders will want a compact crankset paired with a wide-range cassette. A 34×32 is the sensible floor for the sustained sections, but given the length, the altitude, and that 24.52% wall, a 34×34 gives you the extra rescue gear to keep cadence turning when the slope bites hardest. Grinding a too-big gear at low revs for 15.2 km is how you cook your legs before you reach 3228 m — spin, don't muscle.

Summary

Alto de Curíes is a complete HC test: long, steep, high, and unforgiving. At 15.2 km averaging 8.58%, with a 24.52% maximum and a summit at 3228 m, it rewards patient pacing and generous gearing far more than raw ambition. Bring low gears, ride to your FTP, and save something for the altitude.

Length: 15.2 km
Average gradient: 8.58%
Max gradient: 24.52%
Start: 1924 m
Summit: 3228 m
Net gain: 1304 m
Total ascent: 1256 m
Category: HC