Alto de Umbi

Overview

Alto de Umbi is not a climb you settle into — it is a climb you survive. Over just 3.3 km it averages a savage 16.35%, hauling you from a start elevation of 1398 m up to a summit at 1936 m. That works out to a net elevation gain of 538 m and a total ascent of 507 m packed into barely three kilometres of road. There is no gentle valley run-in to hide behind, no false flat to recover on. The numbers alone earn it the HC (hors catégorie) label — the hardest tier there is, above categories 1, 2, 3, and 4. When a road tips this steeply for this long, category stops being a debate and becomes a warning.

How the Gradient Unfolds

The defining feature of Umbi is that its 16.35% average is not softened by long shallow stretches. When the mean is this high, even the "easy" pitches are steep, and the hard ones are ferocious. The maximum gradient hits 26.35% — a wall that will have your front wheel wanting to lift and your cadence collapsing to a grind. Expect the road to lurch between the high teens and the mid-twenties, never releasing you. Across 3.3 km, the elevation profile is essentially a single sustained effort above threshold, with the steepest ramps clustered where they hurt most: after you are already deep in oxygen debt. The gap between the average and the max — roughly ten points — tells you the punishment is delivered in surges, not a steady drip.

Pacing Notes

Forget negative splits here; the goal is simply to keep the pedals turning. A climb this steep pushes almost everyone above their FTP from the first ramp, so the honest strategy is to ride at the lowest power that still keeps you upright and moving. If you do not know your threshold, estimate it first with the FTP estimator, then accept that on 26.35% pitches you will exceed it regardless. Meter your surges: over-cook the first kilometre and the back half of the 538 m gain becomes a walk. Cadence will be low no matter what, so protect your knees by staying seated where traction allows and rising only to clear the very steepest kicks.

Gearing

This is a climb that rewards the biggest cassette you can bolt on. A compact 34-tooth chainring paired with a 34×32 is the practical minimum, and even then the 26.35% ramps will feel geared far too tall. If your derailleur can handle it, go to 34×34 — the extra sprocket is the difference between spinning and stalling on the steepest pitches. Given the 16.35% average sustained over the full 3.3 km, err toward more range, not less; you can always leave a gear unused, but you cannot invent one halfway up a wall.

Summary

Alto de Umbi is a pure test of climbing under duress: short, relentless, and unforgiving from the 1398 m start to the 1936 m summit. Bring low gears, honest pacing, and respect for the gradient.

Length: 3.3 km
Average gradient: 16.35%
Max gradient: 26.35%
Start: 1398 m
Summit: 1936 m
Net gain: 538 m
Total ascent: 507 m
Category: HC