Forcella de Lerosa

Overview

Forcella de Lerosa is a long, high-altitude category-2 climb that stretches 20.6 km from a valley floor already sitting at 1217 m up to a summit of 2022 m. That is 805 m of net elevation gain, matched exactly by 805 m of total ascent — a clean, one-directional climb with no significant descents to give back the height you earn. The headline average gradient of 3.9% sounds gentle, and for long stretches it is. But averages flatten the truth: buried in those 20.6 kilometres is a max pitch of 16.23%, more than four times the average, which tells you this is a climb of contrasts rather than a metronomic grind.

How the Gradient Unfolds

The 3.9% mean is the number to distrust here. Twenty kilometres of true 3.9% would be a tempo spin; the presence of a 16.23% ramp means the road is lumpy, with easier valley kilometres offset by sharp, concentrated efforts. Expect the climb to be back-loaded or punctuated: false flats and shallow drags where you can turn a big gear, broken up by walls that spike toward that 16.23% figure. Because the whole ascent lives between 1217 m and 2022 m, the air thins as you go — the final kilometres toward 2022 m will feel harder than the gradient alone suggests, since altitude quietly steals power near the top.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to a percentage of your FTP and hold it through the shallow sections rather than surging — the 20.6 km length punishes anyone who burns matches early. Ride the flatter kilometres at a controlled sub-threshold pace so you have reserves for the steep ramps toward 16.23%, where the road briefly demands a real spike in power. Losing 10 or 20 watts of margin over the first half is the classic mistake. If you do not know your threshold, plug recent efforts into the FTP estimator and set your ceiling before you start climbing. With a solid number, you can budget across all 805 m of ascent and arrive at 2022 m still turning the pedals cleanly.

Gearing

Do not let the 3.9% average lull you into under-gearing. The 16.23% max pitch is what dictates your setup, and near 2022 m — where thin air compounds fatigue over 20.6 km — you will want spinning gears in reserve. A compact 34-tooth chainring paired with a 34×32 low is a sensible starting point for strong riders, giving enough range to grind the steep ramps without stalling. If you climb at a lighter cadence, tire late, or simply want insurance for the altitude, step up to 34×34. On a climb this long, an extra sprocket is cheap comfort, and it keeps your cadence high on the walls instead of forcing you out of the saddle.

Summary

Forcella de Lerosa rewards patience: a 20.6 km category-2 climb that gains 805 m at a deceptive 3.9% average, spiking to 16.23% and topping out in the thin air at 2022 m. Pace it by threshold, gear for the walls, and respect the altitude.

Length: 20.6 km
Average gradient: 3.9%
Max gradient: 16.23%
Start: 1217 m
Summit: 2022 m
Net gain: 805 m
Total ascent: 805 m
Category: 2