Alto de las Rosas

Overview

Alto de las Rosas is a genuine hors catégorie monster, the kind of climb that measures your season rather than your afternoon. Over 31 km it drags you from a start elevation of 744 m up to a summit at 2790 m, banking 2046 m of net elevation gain along the way. The average gradient reads a sober 6.61%, but averages lie on a climb this long: the total ascent of 2013 m confirms that once the road tilts up, it rarely lets you coast. This is high-altitude endurance riding, where the thin air near the top compounds every percent of grade.

How the Gradient Unfolds

Think of this climb in terms of shape, not landmarks. A 6.61% average sustained across 31 km means there is no meaningful flat to hide in — the gradient hovers persistently around the effort threshold that eats at your legs. The headline figure is the 18.27% maximum, a wall nearly three times steeper than the average. That single number tells you the climb is not uniform: expect ramps that spike hard above the mean, forcing you out of rhythm, followed by stretches that ease back toward the 6.61% baseline. With the summit at 2790 m, the steepest pitches near the top will feel disproportionately savage as oxygen thins. The gap between total ascent (2013 m) and net gain (2046 m) is small, which tells you there is very little downhill relief — you climb almost everything you gain.

Pacing Notes

On a climb of this length, discipline beats bravado. Your FTP is the anchor here: aim to sit comfortably below threshold for the bulk of the 31 km, because burning matches early on a 2046 m ascent leaves nothing for the altitude-affected final kilometres. Treat the 18.27% ramps as the only places to spend a little extra, then settle immediately back to a steady tempo. If you are unsure where your threshold actually sits, run the numbers through the FTP estimator before you commit — pacing a 6.61% average for well over an hour rewards riders who know their limits precisely. The last thing you want is to detonate with the summit still hundreds of metres above you.

Gearing

Do not under-gear this one. A 31 km grind at 6.61% with pitches to 18.27% and altitude sapping your power demands generous ratios. A 34×32 is the sensible minimum for strong climbers who want to protect cadence on the steep ramps, but most riders will thank themselves for a 34×34, which keeps your legs spinning rather than grinding when the wall hits and the air is thin near 2790 m. Given the sheer duration, err toward the easier option — spinning a low gear efficiently across 2046 m of climbing costs far less than muscling a big one.

Summary

Alto de las Rosas is a full HC test of patience, pacing, and gearing. It is long, high, and relentlessly uphill, with just enough gradient variation to punish anyone who rides it flat-out. Respect the distance, gear low, and pace to your threshold.

Length: 31 km
Average gradient: 6.61%
Max gradient: 18.27%
Start: 744 m
Summit: 2790 m
Net gain: 2046 m
Total ascent: 2013 m
Category: HC