Alto del Plato

Overview

Alto del Plato is a monster. At 33.9 km with an average gradient of 5.31%, it belongs firmly in the hors catégorie bracket — the HC label reserved for climbs that break the normal rules of length and elevation. From a start at 1891 m, the road climbs to a summit of 3692 m, a net gain of 1801 m that puts you deep into thin-air territory long before the top.

The average gradient of 5.31% understates the challenge. Over 33.9 km, a "moderate" percentage still adds up to an enormous vertical effort, and the total ascent of 2087 m — well above the 1801 m net figure — tells you the road is far from a single clean ramp. There is rolling, there is respite, and there are pitches that spike to a max gradient of 13.28%.

How the Gradient Unfolds

The gap between the net gain of 1801 m and the total ascent of 2087 m is the key to reading this climb. That extra 286 m of ascent means the profile dips and recovers along the way — you will surrender hard-won height and have to reclaim it. Those descents feel like gifts in the moment but they inflate the real workload.

Averaging 5.31% across 33.9 km, most of the climb sits at a rhythm you can turn over. The danger is the max gradient of 13.28%, more than double the average. These ramps are where riders who paced by feel come undone. Treat the 5.31% as the baseline and hold energy in reserve for the pitches that punch far above it.

Pacing Notes

On a climb this long, pacing is everything. The single most useful number you can bring is your FTP — your functional threshold power. Over 33.9 km you should be riding steadily below threshold, because there is no version of Alto del Plato you win by going out hard. If you do not know your current figure, run the numbers through the FTP estimator before you plan your effort.

Set a target power for the sustained 5.31% sections, then allow yourself to drift over threshold only briefly on the ramps toward the 13.28% max. Everything above 1891 m at the base gets harder as you approach 3692 m — thinner air means the same power costs more. Budget for that fade and start conservatively.

Gearing

Do not under-gear this one. For 33.9 km averaging 5.31% with spikes to 13.28% — and a summit at 3692 m where the air fights you — you want climbing gears with real range. A 34×32 is the sensible minimum for strong riders who can hold a solid cadence on the steeper pitches.

Most riders will be far happier on a 34×34. The extra sprocket keeps your cadence up when the gradient bites near 13.28% and, crucially, protects your legs across the sheer duration of the ascent. Given the 1801 m of net climbing and the extra ascent on top, err toward the easier 34×34 and spin.

Summary

Alto del Plato earns its HC status through sheer scale: 33.9 km, a net gain of 1801 m, a summit at 3692 m, and a total ascent of 2087 m. Respect the 13.28% ramps, gear low, pace off your threshold, and let the mountain come to you.

Length: 33.9 km
Average gradient: 5.31%
Max gradient: 13.28%
Start: 1891 m
Summit: 3692 m
Net gain: 1801 m
Total ascent: 2087 m
Category: HC