Alto de Fontefría

Overview

Alto de Fontefría is a long, patient climb — 21.1 km from a low start at 73 m to a summit of 802 m. That works out to a net elevation gain of 729 m at an average gradient of just 3.45%, which on paper reads as gentle. But the total ascent is 827 m, nearly 100 m more than the net figure, and that gap tells you the road isn't a single clean ramp. It rolls, dips and recovers, meaning you climb more than the summit height alone would suggest. Add a max gradient of 13.19% and Fontefría earns its Category 2 rating not through relentless steepness but through sheer duration.

How the Gradient Unfolds

A 3.45% average across 21.1 km sounds like a climb you can big-ring, and in stretches you can. The catch is the spread. With total ascent (827 m) running 98 m above net gain (729 m), there are false flats and short descents baked into the profile — every metre you give back has to be re-climbed. That inflates the effort well beyond what the tidy average implies. The 13.19% maximum is where the character sharpens: pitches that steep on an otherwise moderate climb force sudden shifts in cadence and load, and they tend to arrive when your legs have already absorbed a long, rolling approach. Treat the average as a lie of comfort and the max as the honest warning.

Pacing Notes

On a climb this long, the winning move is restraint. Anchor your effort to your FTP and hold something in reserve for the 13.19% ramps rather than burning matches on the shallow early kilometres. Over 21.1 km, a percentage point of overcooking compounds into real fatigue by the summit. If you don't know your threshold, run your numbers through the FTP estimator before you plan the ascent — pacing 729 m of gain blind is how riders blow up two-thirds of the way to 802 m. Aim to ride the steady sections just under threshold and let the steep pitches briefly spike you, then settle again on the recoveries the rolling profile hands you.

Gearing

Because the average is modest but the peaks bite at 13.19%, gearing is about protecting your legs for the punchy sections at the end of a 21.1 km grind, not surviving a constant wall. A compact 34-tooth chainring paired with a 34×32 cassette will cover most riders comfortably on the sustained gradients. If you climb at lower cadence, tire on long days, or simply want insurance for the steepest ramps late in the 729 m gain, step up to 34×34. The extra sprocket costs nothing on the flats and buys you a spinning gear exactly when the road kicks toward its maximum.

Summary

Alto de Fontefría rewards patience: a long, rolling Category 2 ascent where the friendly 3.45% average masks 827 m of total climbing and occasional 13.19% teeth. Pace it to your threshold, gear for the steep finish, and let the numbers — not your ego — set the tempo.

Length: 21.1 km
Average gradient: 3.45%
Max gradient: 13.19%
Start: 73 m
Summit: 802 m
Net gain: 729 m
Total ascent: 827 m
Category: 2