Porte del Pasubio

Overview

Porte del Pasubio is one of those climbs that measures itself in stamina rather than sprints. Stretching 29 km from a valley floor at 164 m to a summit of 1916 m, it earns its HC rating not through a single brutal wall but through sheer duration. The average gradient of 6.03% sounds civil on paper, yet holding that number across 29 km is a very different proposition than surviving a short, steep test. This is a climb that rewards riders who can settle into a rhythm and hold it for well over an hour, all the way to a net elevation gain of 1752 m.

How the Gradient Unfolds

The headline figure — 6.03% averaged over 29 km — hides real variety. A max gradient of 17.55% tells you that somewhere on this ascent the road pitches to nearly three times the average, and those ramps are where the climb bares its teeth. Because the mean stays near 6%, the arithmetic is unforgiving: every stretch that eases toward flat must be paid back by a steeper section elsewhere. Expect the profile to breathe — pitches that sag into single digits, then rear back up toward the high teens. With 1737 m of total ascent packed into the run to the top, there is very little genuine recovery. The shape is a long, grinding staircase rather than a smooth ramp.

Pacing Notes

On a climb of this length, pacing is everything. Anchor your effort to your FTP and resist the urge to chase the steep ramps out of the saddle. If you don't know your threshold, run the numbers through the FTP estimator before you commit — a climb spanning 29 km punishes anyone who starts 20 or 30 watts too hot. The smart approach is to ride the shallower sections slightly below threshold, banking energy for the pitches toward 17.55%, where staying seated and spinning will save you. Treat the 1752 m of gain as a budget: spend it evenly, and the summit at 1916 m arrives as a hard-won reward rather than a collapse.

Gearing

Given the combination of length and gradient, gear low and gear generously. For most riders a compact chainring paired with a wide-range cassette is the sensible baseline — a 34×32 will cover the majority of the 6.03% grind and give you a workable cadence when the road tilts. But the 17.55% ramps are where a 34×32 can leave you grinding, so if your legs or your fitness are in any doubt, fit a 34×34 and thank yourself later. On a 29 km effort, a spare sprocket at the back is cheap insurance against blowing up on the steepest slopes.

Summary

Porte del Pasubio is a true test of endurance: 29 km of climbing at 6.03% average with ramps to 17.55%, lifting you 1752 m from base to summit. Pace it patiently, gear it low, and it becomes one of the great long climbs.

Length: 29 km
Average gradient: 6.03%
Max gradient: 17.55%
Start: 164 m
Summit: 1916 m
Net gain: 1752 m
Total ascent: 1737 m
Category: HC