Alto de Matasanos

Overview

Alto de Matasanos is a hors catégorie (HC) climb in Spain — the top rung of the cycling difficulty ladder, above categories 1 through 4. Over 12.4 km it climbs from a start elevation of 945 m to a summit of 2029 m, a net elevation gain of 1084 m. The average gradient is a relentless 8.71%, and the maximum ramp bites at 31.12%. There is nowhere on a climb like this to hide: 8.71% sustained for more than twelve kilometres is the kind of arithmetic that decides races and humbles first-timers.

How the Gradient Unfolds

The headline number is the 8.71% average, but averages flatten out the story. With a maximum pitch of 31.12%, this road holds ramps that are more than three times steeper than the mean — a wall that briefly turns pedalling into a standing, out-of-saddle grind. Because the total ascent (1049 m) sits just below the net elevation gain (1084 m), the profile is essentially a one-way climb: almost every metre gained is a metre kept, with no meaningful descents or false flats to recover the legs. That relentlessness is the defining feature. Expect the gradient to swing well above 8.71% through its steepest sections, then ease only enough to remind you how hard the previous ramp was.

Pacing Notes

On a climb this long and this steep, pacing is everything. Your FTP — the power you can hold for around an hour — is the single most useful anchor here, because 12.4 km at 8.71% will take most riders close to (or beyond) that duration. Ride the opening kilometres conservatively, sitting below threshold, and save your matches for the 31.12% pitches where surges are unavoidable. If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target. The mistake to avoid is starting hot: with 1084 m of climbing ahead and no recovery terrain, early overexertion compounds badly across the full 12.4 km.

Gearing

Gear for survival, not pride. With an 8.71% average and ramps to 31.12%, a compact chainset paired with a wide-range cassette is the sensible baseline. A 34×32 is the minimum I would bring to a climb like this — enough for the sustained sections, but it will feel marginal when the road tips toward its 31.12% maximum. A 34×34 gives you meaningful extra relief on those walls and is the smarter choice for most riders, letting you spin rather than lurch through the steepest metres. When in doubt on an HC climb this steep, err toward the easier gear; you cannot fit a gear you did not bring.

Summary

Alto de Matasanos earns its HC rating honestly: 12.4 km of climbing at 8.71% average, punctuated by a savage 31.12% maximum, taking you from 945 m all the way to 2029 m. With 1084 m of net gain and essentially no respite, it rewards patient pacing and generous gearing. Bring your best legs, your lowest gears, and a realistic sense of your threshold.

Length: 12.4 km
Average gradient: 8.71%
Max gradient: 31.12%
Start: 945 m
Summit: 2029 m
Net gain: 1084 m
Total ascent: 1049 m
Category: HC