Alto de la Paronera

Overview

Alto de la Paronera is a long, patient effort: 23 km of near-continuous climbing that lifts you from a start elevation of 462 m to a summit of 1444 m. On paper the average gradient of 4.27% looks gentle, and for long stretches it is — but the arithmetic hides the truth. Twenty-three kilometres is a very long time in the saddle, and a 982 m net elevation gain has to be earned metre by metre. This is a Category 1 climb, one rung below hors catégorie, and it deserves that ranking not for savage steepness but for sheer sustained length.

How the Gradient Unfolds

The defining feature here is the gap between average and maximum. A 4.27% mean gradient describes a road you can ride in a rhythm, seated, spinning — yet the max gradient of 9.93% is more than double that. That spread tells you the climb is uneven: shallow, almost false-flat sections that let you recover, punctuated by ramps that briefly bite toward 10%. With a total ascent of 969 m spread across the 23 km, you are climbing on average across nearly the entire route, so there is little genuine downhill to reset your legs. The steepest pitches are where the road gains height fastest; treat them as the moments the climb reveals its Category 1 teeth, then settle back into the longer, easier grades that make up most of the ascent.

Pacing Notes

On a climb this long, discipline beats bravado. Ride the 23 km at a percentage of your FTP that you can genuinely hold for the full duration — going out hard on the early slopes will cost you dearly before the 1444 m summit. Use the shallower sections to keep power steady rather than surging, and reserve headroom for the 9.93% ramps so they don't spike you into the red. If you're unsure what wattage to target, run the numbers through the FTP estimator first and pace to that figure. Aim for a slightly conservative effort on the lower slopes; a climb with 982 m of net gain rewards the rider who still has legs in the final third.

Gearing

Because the difficulty is length rather than relentless steepness, most riders will be fine with a compact setup. A 34×32 gives you enough range to spin the 4.27% average comfortably and still turn the pedals on the 9.93% ramps without grinding. If you climb at lower cadences, carry extra weight, or simply want insurance for a 23 km effort, step up to a 34×34 — that extra sprocket keeps your cadence high on the steepest pitches and protects your knees across the full 982 m of gain. Either way, favour the easier gear early.

Summary

Alto de la Paronera is an endurance climb defined by its 23 km length and its 982 m of net elevation gain, not by punishing gradients. Pace it patiently, gear it generously, and respect the 9.93% ramps that break up an otherwise steady 4.27% average.

Length: 23 km
Average gradient: 4.27%
Max gradient: 9.93%
Start: 462 m
Summit: 1444 m
Net gain: 982 m
Total ascent: 969 m
Category: 1