Passo Compione

Overview

Passo Compione is a hors catégorie climb, the hardest rating on the scale, and it earns that label without any statistical trickery. Over 18.5 km it averages 8.74%, a figure that most riders will never sustain on a climb even half this length. It starts at 170 m and finishes at 1785 m, a net elevation gain of 1615 m, with a total ascent of 1559 m once the minor undulations are accounted for. The pitch peaks at 25.39%, so the average, punishing as it is, still hides steeper moments. This is a climb defined by duration and consistency rather than a single famous ramp.

How the Gradient Unfolds

The defining feature of Passo Compione is that the average and the summit tell most of the story. With 8.74% held over 18.5 km, there is very little respite built into the road. The small gap between the net gain of 1615 m and the total ascent of 1559 m confirms it climbs almost continuously, without the false flats or descents that would let you recover and reset. The 25.39% maximum is the sharpest spike, and stretches like it are what turn an already hard gradient into a genuine HC test. Expect the effort to feel relentless rather than punctuated: the road simply tilts up at the bottom and stays there until you reach 1785 m.

Pacing Notes

On a climb this long and this steep, pacing is everything. Base your target on your FTP and hold a power that you know is genuinely sustainable for the better part of an hour or more, because at 8.74% there is nowhere to hide from a bad opening. If you are unsure of your number, run the FTP estimator before you commit to a target. Start conservatively: the danger on Passo Compione is that the steepest pitch, at 25.39%, tempts you into surges that you will pay for across the remaining kilometres. Ride the flattest lines you can find through the sharpest ramps to keep your effort even. With 1615 m of vertical to gain, patience banks time; ambition burns it.

Gearing

Gear for the steep pitches, not the average. A compact 34-tooth chainring paired with a wide cassette is the sensible baseline here. A 34×32 will get many trained riders up the sustained 8.74% sections, but with a maximum of 25.39% and 18.5 km of accumulated fatigue, a 34×34 gives you a meaningful safety margin and lets you spin rather than grind on the worst ramps. If your bike accepts an even larger sprocket, take it — there is no prize for over-gearing an HC climb.

Summary

Passo Compione is a pure endurance climb: long, steep, and almost unbroken from base to summit. Respect the distance, gear generously, and pace off your FTP, and the 1615 m of gain becomes a rhythm rather than a wall.

Length: 18.5 km
Average gradient: 8.74%
Max gradient: 25.39%
Start: 170 m
Summit: 1785 m
Net gain: 1615 m
Total ascent: 1559 m
Category: HC