Sella dei due Corni

Overview

Sella dei due Corni is one of the most uncompromising climbs you can point a bike at. Over 24.6 km it grinds from a valley floor at 485 m all the way to a summit of 2636 m, a net elevation gain of 2151 m. The average gradient reads 8.76%, and unlike many long passes where a gentle run-in dilutes the numbers, that figure is earned over nearly the entire distance. This is a hors catégorie (HC) effort in every sense — the hardest classification on the scale — and it rewards patience far more than ambition.

The total ascent of 2484 m is larger than the net gain, which tells you the road is not a single clean ramp: there are stretches where you claw back a little before the mountain takes it away again. But make no mistake, the defining sensation here is up, and lots of it.

How the Gradient Unfolds

With a 24.6 km length and an 8.76% average, the arithmetic is brutal in its consistency. A climb this long that still averages nearly 9% simply cannot hide easy kilometres — there is very little coasting to be found. The gap between the 2484 m total ascent and the 2151 m net gain (a difference of 333 m) points to short descents or false flats punctuating the effort, each one forcing you to re-launch a rhythm you'd rather protect.

Expect the mountain to arrive in blocks: steep pitches that pin you to the saddle, brief relents that never quite let the legs recover, then more of the same. Because the climb tops out at 2636 m, the final third also thins the air, and any pitch above the average will feel harsher than the number suggests.

Pacing Notes

On a climb of this magnitude, pacing is not a tactic — it's survival. Anchor your effort to your FTP and resist the urge to chase the early ramps. At 8.76% for 24.6 km, the winning move is a metronomic, sustainable output held for well over an hour.

A sensible target is to sit just below threshold on the steady sections and allow the steepest pitches to nudge you up, rather than starting hard and fading. If you're unsure of your number, run the FTP estimator before you commit — pacing 2151 m of vertical off a guess is how good days turn into walks.

Fuel early and often. The upper slopes near 2636 m are no place to discover you've under-eaten.

Gearing

Do not under-gear this climb. For most riders a compact 34-tooth chainring paired with a wide cassette is the minimum. A 34×32 will get strong climbers up the average grade, but on a 24.6 km, 8.76% wall the smart choice for the majority is 34×34, which buys you the cadence to spin rather than grind. If your setup allows an even larger sprocket, take it — fresh knees at the summit are worth more than pride. The goal is to keep turning the pedals smoothly across all 2151 m of gain.

Summary

Sella dei due Corni is a full HC test: long, steep, and honest. Respect the 8.76% average, gear generously, pace off your FTP, and the summit at 2636 m is yours.

Length: 24.6 km
Average gradient: 8.76%
Max gradient: n/a
Start: 485 m
Summit: 2636 m
Net gain: 2151 m
Total ascent: 2484 m
Category: HC