Passo delle Radici

Overview

Passo delle Radici is a hors catégorie climb that leaves no room to hide. Over 14.7 km it averages 9.15%, lifting you from a start elevation of 284 m to a summit at 1629 m. That works out to a net elevation gain of 1345 m, with a total ascent of 1323 m once the small rolling losses are accounted for. An average approaching double digits over nearly fifteen kilometres puts this firmly in the top tier of European climbs — the HC label is earned, not decorative. With a max gradient of 21.18%, there are moments here that reduce even strong riders to a grinding survival cadence.

How the Gradient Unfolds

The defining feature of Passo delle Radici is its unrelenting consistency. A 9.15% average sustained across 14.7 km means there are precious few false flats or recovery sections to break the effort. Where many long climbs let you settle into a rhythm and coast the easier pitches, this one keeps the pressure on almost continuously. The 21.18% max gradient tells you that the hardest ramps spike more than twelve points above the average, so expect sharp pitches that force you well out of your comfort zone before easing back toward that punishing baseline. Because the net gain (1345 m) sits close to the total ascent (1323 m), the road climbs almost monotonically — there is very little descending to hand back altitude, which reinforces just how relentlessly upward the route runs.

Pacing Notes

On a climb this sustained, discipline beats bravado. The single biggest mistake is going too hard on the lower slopes and paying for it near the 1629 m summit. Anchor your effort to your FTP: on an HC climb of this length, most riders should target a sustainable percentage of threshold and hold it, letting the steep ramps briefly push power above that ceiling before settling back. If you don't know your threshold, run the numbers through the FTP estimator before you commit to a pace. With 1345 m to gain, the climb will likely take the better part of an hour or more, so treat the first third as the setup, not the race. Keep something in reserve for the 21.18% pitches, where cadence collapses and the temptation to overpower the gear is strongest.

Gearing

Gear for the average, then gear again for the max. A 9.15% average over 14.7 km is already demanding, but the 21.18% ramps are what dictate your setup. A compact chainring paired with a wide-range cassette is the sensible baseline: 34×32 will get many trained riders up the sustained sections, but the steep pitches argue strongly for going lower still. If your frame and derailleur allow it, 34×34 gives you the extra margin to keep a spinnable cadence when the road kicks toward 21.18%. On an HC climb, err toward easier gearing — spinning a low gear preserves your legs far better than muscling a hard one.

Summary

Passo delle Radici is a pure test of sustained climbing: long, steep, and almost entirely upward. Respect the 9.15% average, gear for the 21.18% ramps, and pace to your threshold — and the 1629 m summit is well within reach.

Length: 14.7 km
Average gradient: 9.15%
Max gradient: 21.18%
Start: 284 m
Summit: 1629 m
Net gain: 1345 m
Total ascent: 1323 m
Category: HC