Alto de Juncal

Overview

Alto de Juncal is a category-1 climb that stretches 16.1 km from base to summit, gaining 828 m of net elevation along the way. What sets it apart isn't just the length but the thin air it lives in: you start at 2209 m and top out at 3037 m, meaning every pedal stroke happens well above the altitude where most riders train. The average gradient of 5.15% reads as moderate on paper, but that number hides both the sustained effort of the distance and the sharper ramps buried inside it, where the road tilts as steeply as 10.38%.

With a total ascent of 813 m across those 16.1 km, this is a climb of patience rather than raw brutality. It rewards riders who can settle into a rhythm and hold it for the better part of an hour, while punishing anyone who burns matches too early.

How the Gradient Unfolds

The headline figure is 5.15% average, but averages smooth over the texture that defines Juncal. Because the net gain (828 m) slightly exceeds the total ascent (813 m), the climb is almost relentlessly uphill with only the faintest relief — there is very little false-flat or descent to recover on. That makes the effort feel more continuous than the modest average suggests.

The 10.38% max gradient is the moment that matters most. When the road doubles the average pitch, your legs feel it immediately at altitude, and the recovery afterward comes slowly. Expect the climb to alternate between long, steady stretches near the 5% mark and shorter kicks that force a gear change and a spike in effort. Reading these transitions well is the difference between a controlled ascent and a blow-up.

Pacing Notes

At 16.1 km, Juncal is long enough that pacing by feel alone is risky, especially with the altitude dulling your perceived exertion. Anchor your effort to power instead. Aim to ride the sustained sections just below your FTP, leaving a reserve for the 10.38% ramps where the cost of going anaerobic is highest and the recovery slowest above 2209 m.

If you don't have a recent threshold number, run one through the FTP estimator before you commit to a pacing target. On a climb this sustained, a target that's even slightly too ambitious compounds over the full 16.1 km — the thin air magnifies every over-effort. Ride the average, respect the ramps, and keep something in the tank for the final push toward 3037 m.

Gearing

Given the length and the 10.38% pitches, gear for spinning rather than grinding. A compact 34-tooth chainring is the sensible front choice. Pairing it with a 34×32 setup covers most riders comfortably on the sustained 5.15% grades, but if you want insurance for the steepest ramps at altitude — where cadence collapses fastest — a 34×34 gives you that extra bailout gear. On a climb where you're working above 2209 m for the better part of 16.1 km, the lower option is rarely a mistake.

Summary

Alto de Juncal is a high-altitude endurance test: 16.1 km at 5.15% average, punctuated by ramps to 10.38%, all delivered in the rarefied air between 2209 m and 3037 m. Pace to power, gear low, and treat the distance with the respect it demands.

Length: 16.1 km
Average gradient: 5.15%
Max gradient: 10.38%
Start: 2209 m
Summit: 3037 m
Net gain: 828 m
Total ascent: 813 m
Category: 1