Passo Principe - Grasleitenpass

Overview

Passo Principe - Grasleitenpass is a hors catégorie (HC) climb, the hardest classification there is, and its numbers explain why. Over 14.1 km it averages 7.59%, lifting you from a valley floor at 718 m to a summit at 1787 m. That is a net gain of 1069 m, with 1041 m of total ascent packed into a road that rarely lets you settle. The 18.13% max gradient is not a decorative statistic — it is a wall you will meet with tired legs, and it sits more than ten points above the average (18.13 − 7.59 = 10.54).

How the Gradient Unfolds

The shape here is defined by consistency punctuated by cruelty. A 7.59% average across 14.1 km means there is very little genuine rest — this is not a climb with long false flats to recover on. Because the net gain (1069 m) is larger than the total measured ascent (1041 m), the profile is almost relentlessly upward with only minor undulation, meaning essentially every metre of road is spent climbing rather than rolling.

The 18.13% max is the defining feature. Whether it arrives early, mid-climb, or near the top, that ramp more than doubles the effort of the average slope. Expect the gradient to hover around and above 7.59% for long stretches, with sharper pitches that spike well into double digits before easing back toward the mean.

Pacing Notes

Discipline wins here. At 14.1 km and 7.59%, this is a sustained effort measured in tens of minutes, so it must be paced off your threshold, not your ego. Ride the opening kilometres a touch under your FTP to leave headroom for the 18.13% ramp — the single biggest mistake is burning matches early and arriving at the steepest section already redlined.

If you do not know your threshold power, use the FTP estimator to set a target before you start. On a climb this long, holding a steady, repeatable effort will get you to 1787 m faster than a series of surges and recoveries.

Gearing

Do not under-gear an HC climb. For most riders a compact 34-tooth chainring paired with a wide cassette is the right call. A 34×32 is a sensible baseline for strong climbers who can hold cadence on the average 7.59% pitches, but the 18.13% max is where a 34×32 can leave you grinding at an unsustainable cadence.

If you are carrying any fatigue, or you simply want to spin the steep ramp rather than muscle it, a 34×34 gives you the extra range to keep your legs turning when the road kicks up. Given 1069 m of climbing to survive, err toward the easier ratio — you will never regret having one more gear in reserve.

Summary

Passo Principe - Grasleitenpass earns its HC label honestly: 14.1 km, a punishing 7.59% average, and an 18.13% spike, all stacked into a 1069 m ascent. Pace it off threshold, gear it generously, and respect the wall.

Length: 14.1 km
Average gradient: 7.59%
Max gradient: 18.13%
Start: 718 m
Summit: 1787 m
Net gain: 1069 m
Total ascent: 1041 m
Category: HC