Sella del Legnone

Overview

Sella del Legnone is a hors catégorie (HC) climb, the hardest rung on the road-cycling ladder above categories 1 through 4. Over 11.9 km it gains 1238 m of net elevation, rising from a start at 224 m to a summit at 1462 m. The average gradient is a relentless 10.41%, and the steepest pitch bites at 21.29%. That combination — double-digit average across nearly twelve kilometres — puts it among the most punishing sustained efforts a rider can take on. There is no easing into this one; the numbers demand respect from the first pedal stroke.

How the Gradient Unfolds

An average of 10.41% is not a figure that hides gentle stretches. To hold that mean over 11.9 km, the climb must stack ramp upon ramp, with the 21.29% maximum marking the cruellest wall. Expect the gradient to hover in the low-teens for long passages, punctuated by pitches that spike toward that 21.29% peak and short reprieves that still tilt upward. The gap between the net gain of 1238 m and the total ascent of 1201 m is small, which tells you the road climbs almost continuously — there are no meaningful descents to recover on, no false flats to spin out the legs. It simply goes up, and keeps going up.

Pacing Notes

On a climb this steep and this long, pacing is everything. The single biggest mistake is chasing the early ramps and blowing through your ceiling before the halfway mark. Anchor your effort to your FTP and hold a wattage you can sustain for the full duration rather than a heart rate that will keep drifting upward. If you do not know your threshold, run the numbers through the FTP estimator before you commit to the climb. On pitches near 21.29%, cadence collapses and power surges — let those sections come to you, absorb them, and settle back to your target the moment the road relents. Fuel and hydrate early; over 11.9 km of climbing you cannot afford to run dry.

Gearing

Gear for survival, not for pride. At 10.41% average with spikes to 21.29%, you want the lowest ratios you can fit. A compact 34-tooth chainring paired with a 34×32 cassette is a sensible floor, but on this climb a 34×34 is the smarter choice — that extra sprocket buys you cadence and preserves your legs on the steepest ramps. Riders who spin rather than grind will hold their pace far better across 11.9 km. If your setup allows something even easier, take it; nobody regrets an extra cog when the road hits 21.29%.

Summary

Sella del Legnone earns its HC label without argument: 11.9 km of climbing at 10.41% average, topping out at 21.29%, lifting you 1238 m from valley to summit. Pace to your threshold, gear low, and treat it as the sustained battle it is.

Length: 11.9 km
Average gradient: 10.41%
Max gradient: 21.29%
Start: 224 m
Summit: 1462 m
Net gain: 1238 m
Total ascent: 1201 m
Category: HC