Pas de l'Incise / Passo dell'Incisa

Overview

The Pas de l'Incise, known on the Italian side as the Passo dell'Incisa, is a hors catégorie (HC) climb — the hardest classification there is, sitting above categories 1 through 4. Its difficulty comes not from a single savage wall but from sheer scale. Over 34.8 km the road climbs from a valley floor at 28 m to a summit of 1903 m, delivering a net elevation gain of 1875 m. The average gradient reads a deceptively civil 5.39%, but on a climb this long that number hides a great deal of variety — and a maximum pitch of 14.97% that will find you well before the top.

How the Gradient Unfolds

A 5.39% average across 34.8 km tells you this is a climb of endurance rather than explosive power. The total ascent of 1858 m is marginally less than the 1875 m net gain, which means the road runs almost relentlessly upward with barely a false-flat descent to break the rhythm — you gain what you climb and give almost nothing back. That consistency is the defining feature: long, steady ramps that sit near or a little above the average, punctuated by steeper kicks that peak at 14.97%. Expect the hardest slopes to bite where the road pinches through the steeper mid and upper sections, forcing repeated shifts between seated tempo and standing efforts. On a climb this size, the challenge is managing dozens of those transitions without burning through your reserves early.

Pacing Notes

The single biggest mistake on a 34.8 km HC climb is starting too hard. With 1875 m to gain, discipline pays. Anchor your effort to your FTP: for a sustained climb of this length, most riders will want to settle just below threshold and hold it, saving anything extra for the 14.97% pitches where the gradient — not your ambition — dictates the cost. If you don't have a current threshold number, run yours through the FTP estimator before you commit to a pacing plan. Break the 34.8 km into mental blocks, drink and eat early, and treat the steeper ramps as brief overdrafts to be repaid on the shallower stretches that follow.

Gearing

Gear for the duration, not just the steepest metre. On an HC climb that averages 5.39% but spikes to 14.97%, low ratios protect your legs across the full 34.8 km. A compact 34-tooth chainring paired with a wide cassette is the sensible baseline: a 34×32 will carry strong climbers through most of the gradient, while a 34×34 gives you a meaningful safety margin for the 14.97% pitches and for the hour-plus of accumulated fatigue near the 1903 m summit. If your bike accepts it, err toward the easier 34×34 — spinning a low gear costs far less over 34.8 km than grinding one.

Summary

The Pas de l'Incise is a true test of climbing endurance: a long, steady, unrelenting HC ascent where patience and gearing matter more than raw power. Pace it off your threshold, gear low, and respect the distance.

Length — 34.8 km
Average gradient — 5.39%
Max gradient — 14.97%
Start — 28 m
Summit — 1903 m
Net gain — 1875 m
Total ascent — 1858 m
Category — HC