Alto de las Torres

Overview

Alto de las Torres is a genuine hors catégorie effort, the kind of climb that rewards patience and punishes ambition. Over 26.6 km the road lifts you from 1780 m at the base to a summit of 3352 m, a net gain of 1572 m. The average gradient of 5.9% sounds civilised, and in isolation each kilometre is. Strung together across more than twenty-six of them, though, that steady tax on your legs becomes the defining challenge. This is an HC climb not because any single ramp is brutal but because the demand never lets up.

How the Gradient Unfolds

The headline number to respect here is the gap between the average and the maximum. At 5.9% mean gradient with pitches reaching 10.19%, the climb is not uniform — it breathes. Expect long stretches that sit close to or just under the average, broken by steeper kicks that nudge toward that 10.19% ceiling. Because the total ascent is 1558 m against a net gain of 1572 m, the profile is very nearly a pure climb: there is almost no descending or false-flat give-back on the way up. Every metre of elevation you earn, you keep. That consistency is a double-edged sword — no recovery pitches, but also no nasty surprises once you know the shape. Ride the average, save something for the kicks, and the mountain stays honest.

Pacing Notes

The single biggest lever on a climb this long is discipline in the opening kilometres. With 26.6 km ahead, going out even slightly too hard costs you far more than it does on a short climb, because there is no top to reach before the damage compounds. Anchor your effort to your sustainable power rather than to how you feel at the base. A useful target is to sit just under your FTP for the bulk of the climb, keeping a small reserve for the 10.19% ramps rather than blowing through it early. If you do not know your threshold, run the numbers through the FTP estimator before you attempt this one — pacing a 1572 m ascent by feel alone is how good days unravel. Remember too that the summit sits at 3352 m, so the thinning air late in the climb will quietly clip the top off your usual output.

Gearing

Gear for the long haul, not for how strong you feel in the car park. For most riders a compact chainring paired with a wide-range cassette is the right call on a 5.9% average that spikes to 10.19%. A 34×32 is the sensible floor here and will get many fit riders to the top, but on a climb of 26.6 km at altitude, the extra margin of a 34×34 is worth having. That larger sprocket lets you spin the steep pitches without cranking your cadence into the red, preserving your legs for the sheer duration of the effort. When in doubt on an HC climb this long, choose the easier gear.

Summary

Alto de las Torres is a patience test dressed as a bike climb: 26.6 km of near-relentless ascent to a high-altitude summit. Pace it conservatively, gear it generously, and let the average do the work.

Length: 26.6 km
Average gradient: 5.9%
Max gradient: 10.19%
Start: 1780 m
Summit: 3352 m
Net gain: 1572 m
Total ascent: 1558 m
Category: HC