Sella Pass

Overview

Sella Pass is a genuine hors catégorie test, and its dimensions tell you why. At 30.2 km, this is one of the longer sustained climbs you can point a bike at, and it earns its HC label through duration as much as steepness. From a start elevation of 470 m it grinds all the way up to a 2210 m summit, a net elevation gain of 1740 m spread across a road that simply refuses to release you. The average gradient sits at 5.76%, which sounds civilised until you factor in the total ascent of 1722 m and the sheer time you will spend turning the pedals. This is a climb measured in the better part of an hour or more, not minutes.

How the Gradient Unfolds

The headline average of 5.76% hides the real character of the ascent. A max gradient of 18.76% means there are ramps here that are more than three times steeper than the mean, and those spikes are what break a rhythm you have carefully built. Because the net gain of 1740 m is almost identical to the total ascent of 1722 m, the road climbs with very little relief — there are only a handful of metres of descending across the whole 30.2 km. Expect the profile to pulse between shallower drags that let you breathe and sharp kicks toward that 18.76% ceiling. The gap between average and maximum is the number to respect: pace for the 5.76%, but keep something in reserve for the pitches that spike far beyond it.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to your FTP and hold a sustainable percentage of it, because 30.2 km at 5.76% will punish anyone who redlines early. If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target. The steep ramps toward 18.76% will force short surges above threshold — let them, then settle straight back down rather than chasing the power you just spent. With 1740 m of net gain ahead, the goal is a metronomic effort that leaves you climbing strongly in the final kilometres, not clinging on.

Gearing

Gear for the pitches, not the average. On an HC climb topping out at 18.76% and dragging on for 30.2 km, a compact 34-tooth chainring paired with a wide cassette is the sensible baseline. A 34×32 will get most riders up the shallower and mid sections in a workable cadence, but the sharpest ramps make a strong case for a 34×34, which buys you the extra spin you will want when the gradient bites and your legs are already deep into the 1722 m of climbing. If your bike accepts it, run the 34×34 and be grateful on the steep bits.

Summary

Sella Pass is a long, honest HC climb that rewards patience and punishes over-eagerness. Respect the length, gear low, and pace to your threshold.

Length: 30.2 km
Average gradient: 5.76%
Max gradient: 18.76%
Start: 470 m
Summit: 2210 m
Net gain: 1740 m
Total ascent: 1722 m
Category: HC