Pas de la Corne

Overview

Pas de la Corne is a hors catégorie climb that gives you nowhere to hide. Over 10.2 km it averages a punishing 10%, hauling you from a near-sea-level start at 11 m all the way to a 1034 m summit. That is 1023 m of net elevation gain packed into just over ten kilometres, with a total ascent of 996 m once the small undulations are counted. An HC rating is the sport's way of saying a climb sits beyond the normal 1-to-4 scale, and everything about this ascent — the length, the relentless average, the 21.88% peak — earns that label.

How the Gradient Unfolds

A 10% average is already severe, but averages flatten the truth. On Pas de la Corne the road bites hardest where it spikes to 21.88%, more than double the mean. Those ramps mean long stretches must sit below 10% simply to balance the maths, so expect the climb to breathe in pulses: a savage pitch, a fractional easing, then another wall. There are no flat recovery kilometres to bank speed. With 1023 m of net gain over 10.2 km, the vertical rarely relents from the moment you leave 11 m until you crest at 1034 m. Ride it as one sustained effort broken by short, sharp surges rather than a steady tempo you can settle into.

Pacing Notes

Do not chase the early ramps. On a climb averaging 10% for 10.2 km, going into the red on the first steep pitch is the classic way to blow before the halfway point. Anchor your effort to your FTP and hold a wattage you can sustain for the full duration — roughly 30 to 45 minutes for most riders — rather than reacting to every gradient spike. When the road jumps toward 21.88%, accept that your power will surge briefly; let it settle again on the shallower pitches instead of trying to hold speed. If you are unsure what number to target, run your recent efforts through the FTP estimator first, then set a ceiling and defend it. Discipline in the opening kilometres buys you the legs to survive the top.

Gearing

Gear for the walls, not the average. On pitches touching 21.88%, a compact 34-tooth chainring paired with a 34×32 cassette is the sensible minimum, and many riders will want the extra rescue gear of a 34×34. The difference between 34×32 and 34×34 feels small on paper but matters enormously when you are grinding a 20%-plus ramp at the end of a 10.2 km effort — the lower ratio lets you keep the pedals turning instead of lurching to a near-standstill. If your legs or your gravel-influenced setup allow anything lower, take it. There is no shame in spinning up an HC climb.

Summary

Pas de la Corne is a short, savage HC ascent: relentless double-digit gradients, brutal spikes, and no genuine recovery from bottom to top. Respect the average, fear the maximum, and gear low.

Length: 10.2 km
Average gradient: 10%
Max gradient: 21.88%
Start: 11 m
Summit: 1034 m
Net gain: 1023 m
Total ascent: 996 m
Category: HC