Forcella Magna

Overview

Forcella Magna is a true hors catégorie (HC) climb, the hardest classification on the scale that runs HC, 1, 2, 3, 4. Over 22.1 km it drags you from a start elevation of 323 m up to a summit at 2146 m — a net gain of 1823 m and 1805 m of total ascent, meaning the road almost never gives anything back. The average gradient of 8.24% is relentless for a climb this long, and the max touches a leg-snapping 21.54%. This is a full-day objective that rewards patience and punishes anyone who starts too hard.

How the Gradient Unfolds

The headline number is the 8.24% average, but averages hide the story. On a climb of 22.1 km, sustaining that mean over 1823 m of net gain means long stretches sit above the average, offset by only brief easings. The near-total absence of descent — 1805 m of total ascent against 1823 m of net gain — tells you there are essentially no recovery downhills to reset your legs. The 21.54% max is the sting in the tail: a pitch steep enough that momentum and gearing, not fitness alone, decide whether you keep rolling or grind to a walk. Expect the gradient to bite hardest where the road ramps toward the higher, thinner air near 2146 m.

Pacing Notes

Climbs of this length are won by discipline. Anchor your effort to your FTP and aim to hold a steady, sustainable percentage of it rather than chasing surges. At 8.24% average over 22.1 km, even small overages early compound into a blow-up long before the 2146 m summit. If you don't know your threshold, run the numbers through the FTP estimator before you commit to a target power. Treat the 21.54% max as a place to spend a short, controlled match — get out of the saddle, keep cadence alive, and settle straight back into rhythm once it relents. Budget for the altitude too: the final metres toward 2146 m will feel harder than the gradient alone suggests.

Gearing

With a 21.54% max and 8.24% sustained over 1823 m of climbing, gear low and gear early. A compact 34-tooth inner chainring is the sensible starting point. Paired with a 34×32, you have a workable ratio for the long steady sections, but the steepest ramps toward that 21.54% pitch will test it. If you have any doubt about your climbing legs on a 22.1 km effort — or you're carrying fatigue — step down to a 34×34 for extra margin. On a climb this relentless, a spare gear you never use costs nothing; a gear you wish you had costs you the whole day.

Summary

Forcella Magna is a benchmark HC ascent: long, steep, and unrelenting from 323 m to 2146 m. Respect the 22.1 km distance, pace off your threshold, gear low for the 21.54% max, and the 1823 m of climbing becomes an achievement rather than an ordeal.

Length: 22.1 km
Average gradient: 8.24%
Max gradient: 21.54%
Start: 323 m
Summit: 2146 m
Net gain: 1823 m
Total ascent: 1805 m
Category: HC