Fortschellscharte - Forcella di San Cassiano

Overview

The Fortschellscharte - Forcella di San Cassiano is a full-blooded hors catégorie climb, and the numbers make no attempt to hide it. Over 17.2 km the road lifts you from 536 m to a summit of 2301 m, a net gain of 1765 m. That works out to a relentless 10.24% average gradient — not a figure padded by a single wall and a lot of easy recovery, but a sustained demand that barely relents across the entire ascent. The HC rating is the hardest category on the scale, sitting above 1, 2, 3 and 4, and this climb earns it on length and slope alone.

How the Gradient Unfolds

A 10.24% average is brutal in its own right, but the defining feature here is the spread between that average and the 29.97% maximum. Nearly 30% is close to the limit of what a road bike can be ridden up seated, and stretches like that reshape how the whole climb feels. Because the mean sits so high, the "easier" sections are still steep — there is very little genuine respite. The total ascent of 1726 m is fractionally below the 1765 m net gain, which tells you the profile climbs almost monotonically: no meaningful descents to break up the effort, just a steady grind punctuated by ramps that spike well into the twenties. Expect the steepest pitches to arrive without warning, and to force sharp, expensive surges if you have not left yourself a margin.

Pacing Notes

On a climb this long and this steep, discipline in the opening kilometres decides how the summit feels. The single biggest mistake is anchoring your early effort to the ramps rather than the average. Ride to a sustainable power target rather than to the gradient. Your FTP is the reference point here: on an HC effort lasting well over an hour, holding a shade below threshold on the sustained sections buys you the headroom to absorb the 29.97% spikes without blowing apart. If you do not know your number, run it through the FTP estimator before you commit. Meter the steepest pitches — accept a slower speed and protect your legs, because there is a great deal of climbing still to come after each wall.

Gearing

Do not under-gear this one. With a 10.24% average sustained across 17.2 km and ramps touching 29.97%, you want the lowest ratio you can reasonably fit. A compact 34-tooth chainring paired with a wide-range cassette is the sensible baseline. A 34×32 will get most fit riders up the sustained sections, but on the near-30% pitches it leaves little in reserve. If your derailleur allows it, step to a 34×34 — that extra sprocket is the difference between spinning through the steepest ramps and grinding to a near-standstill. For heavier riders or anyone not at peak fitness, go lower still if your drivetrain permits. Cadence, not force, keeps you moving on gradients this severe.

Summary

The Fortschellscharte - Forcella di San Cassiano is a genuine HC test: long, unrelentingly steep, and topped by ramps that flirt with the limits of ridability. Gear low, pace to your threshold, and respect the 1765 m of vertical between you and the summit.

Length: 17.2 km
Average gradient: 10.24%
Max gradient: 29.97%
Start: 536 m
Summit: 2301 m
Net gain: 1765 m
Total ascent: 1726 m
Category: HC