coll des Vent

Overview

The Coll des Vent is a short climb that hits hard. Over just 3.1 km it averages 9.63% and gains 302 m of net elevation, rising from a low start at 21 m to a summit of 323 m. That is a category 2 rating earned entirely through steepness rather than length — there is nowhere to hide on a road this consistently pitched. With a maximum gradient of 14.37%, the Vent demands respect from the first pedal stroke and punishes anyone who treats it like a rolling warm-up.

How the Gradient Unfolds

The defining feature here is relentlessness. A 9.63% average across 3.1 km means the road rarely dips below the point where your legs start to burn and stay there. The total ascent of 260 m sits below the 302 m net gain, which tells you the climb is almost purely uphill — there are no meaningful descents or false flats to recover on, just an unbroken drag toward the top.

The gradient is not perfectly even, though. The gap between the 9.63% average and the 14.37% maximum is nearly five percentage points, so expect ramps that surge well into double digits. These steep bites are where the climb is won or lost. When the road tilts toward its 14.37% max, your speed drops sharply and cadence collapses if you are already at your limit. The smart approach is to read the road ahead and shed effort slightly before the worst pitches so you are not blown apart on them.

Pacing Notes

Because the Vent is so short, the temptation is to go out hard. Resist it. A climb this steep will exceed your threshold effort almost the moment you begin, and 3.1 km is long enough that early over-cooking leaves you crawling near the summit at 323 m. Anchor your pacing to your FTP: on a wall averaging 9.63%, holding just above threshold is realistic for a fit rider, but only if you meter the surges rather than attack them.

Aim to keep a steady effort through the shallower sections and accept short spikes above threshold only on the steepest ramps toward 14.37%, then settle back. If you do not know your threshold number, run it through the FTP estimator before you plan your ride — pacing a climb like this by feel alone usually ends badly.

Gearing

Steepness, not distance, dictates your gearing choice on the Coll des Vent. With a 9.63% average and pitches reaching 14.37%, a compact chainring paired with a wide-range cassette is strongly advised. A 34×32 will get most trained riders up the climb while keeping cadence tolerable on the moderate sections. But on the 14.37% ramps, a 34×32 can force you into a grinding, low-cadence slog that drains your legs fast. If you have any doubt about your climbing legs — or you are carrying fatigue — go with a 34×34. That extra sprocket buys you the spin you need to defend your cadence when the road stands up, and on a climb this consistently steep, protecting cadence is protecting your race.

Summary

The Coll des Vent is a pure test of climbing power packed into 3.1 km. It never eases, it spikes viciously, and it rewards patient pacing and generous gearing. Come prepared to suffer from the bottom, and the 323 m summit will feel earned.

Length: 3.1 km
Average gradient: 9.63%
Max gradient: 14.37%
Start: 21 m
Summit: 323 m
Net gain: 302 m
Total ascent: 260 m
Category: 2