La Sellaccia

Overview

La Sellaccia is an HC climb — hors catégorie, the hardest tier before the numbered categories begin — and its numbers explain the label without any need for embellishment. Over 24.6 km it lifts you from a start elevation of 378 m to a summit of 2363 m, a net elevation gain of 1985 m. The average gradient of 8.06% is not a rolling road average softened by flat kilometers; sustained for nearly 25 km, it is a wall that simply refuses to end. With a total ascent of 1968 m, almost every meter of forward progress is also a meter upward.

How the Gradient Unfolds

An 8.06% average across 24.6 km is punishing precisely because it is relentless rather than spiky. But the maximum gradient of 29.05% tells you the road is not uniform — there are pitches here more than three and a half times steeper than the average. Expect the climb to breathe: stretches near or just above 8% that let you settle into a rhythm, interrupted by ramps that spike toward that 29.05% ceiling and force you out of the saddle. Because the summit sits at 2363 m, the final kilometers also unfold at altitude, where thinner air quietly trims the power you can hold. The gap between net gain (1985 m) and total ascent (1968 m) is small, confirming this is an almost entirely uphill effort with negligible respite.

Pacing Notes

The single biggest mistake on a climb this long is starting too hard. At 24.6 km, La Sellaccia rewards discipline over ambition. Anchor your effort to your FTP: for a sustained HC climb, most riders should sit just below threshold on the steady 8% sections and accept that the ramps toward 29.05% will briefly push them into the red — that is fine, provided you recover on the shallower pitches rather than chasing a number.

If you do not know your threshold, estimate it first with the FTP estimator, then work backward to a target you can actually hold for the better part of an hour and beyond. Remember that with 1985 m of climbing and a finish at 2363 m, fatigue and altitude compound in the final third — bank nothing you cannot sustain.

Gearing

This is a climb to gear generously for. An 8.06% average sustained over 24.6 km, with ramps toward 29.05%, means a road-standard setup will have you grinding at low cadence for far too long. A compact crankset paired with a wide-range cassette is the sensible baseline: 34×32 is the minimum most riders will want, and on the steepest pitches even that can feel over-geared. If your legs are not fresh or the 29.05% sections concern you, fit a 34×34 — the extra sprocket buys cadence exactly where the road bites hardest, and cadence is what keeps 1985 m of gain from grinding you down.

Summary

La Sellaccia earns its HC rating honestly: long, steep, and finishing high. Pace it against your FTP, gear low, and respect the altitude waiting at the top.

Length: 24.6 km
Average gradient: 8.06%
Max gradient: 29.05%
Start: 378 m
Summit: 2363 m
Net gain: 1985 m
Total ascent: 1968 m
Category: HC