Col d'Entre Deux Pertuis

Overview

The Col d'Entre Deux Pertuis is the kind of climb that earns its hors catégorie label before you've even turned a pedal in anger. Over 11.7 km it averages 9.32%, hauling you from a start elevation of 810 m to a summit at 1902 m. That's a net gain of 1092 m, with 1039 m logged as total ascent — meaning almost every metre of the road tilts upward, with barely a false flat to hide behind. There is no easing-in phase here. An HC rating is the sport's way of saying a climb sits beyond the normal scale, and at nearly 9.32% sustained across 11.7 km, this one belongs there without argument.

How the Gradient Unfolds

The defining feature of this climb is relentlessness. A 9.32% average across 11.7 km is punishing not because of a single savage ramp, but because the road simply refuses to relent. With 1092 m of net gain packed into that distance, the arithmetic is unforgiving: you are climbing roughly 93 metres of vertical for every kilometre travelled. The gap between the 1092 m net gain and the 1039 m total ascent is small, which tells you there are no meaningful descents or recovery dips to reset your legs. Whatever height you take on, you keep. Plan for a gradient that hovers around and above that 9.32% figure for the full 11.7 km rather than expecting relief.

Pacing Notes

On a climb this steep and this long, discipline beats bravado. Your FTP is the number that decides your fate here — go out above threshold in the first few kilometres and the back half of the 11.7 km will unravel completely. Aim to settle just under threshold and hold it, because at 9.32% there is no coasting to recover a burnt match. If you're unsure of your ceiling, run the numbers first with the FTP estimator so you're pacing to real data rather than optimism. Meter your effort against the full 1092 m of climbing, not the section in front of your wheel.

Gearing

Do not under-gear this one. A 9.32% average sustained for 11.7 km demands the lowest ratios most riders own. A compact 34-tooth chainring paired with a 34×32 cassette is a sensible baseline for strong climbers, but plenty of riders will be grateful for the extra range of a 34×34 to keep cadence up and the knees healthy through the steepest stretches. Given there's 1039 m of total ascent to grind out with almost no respite, err toward the easier 34×34 if you're in any doubt — spinning a smaller gear beats grinding to a standstill halfway up an HC climb.

Summary

The Col d'Entre Deux Pertuis is a pure HC test: 11.7 km, 9.32% average, and 1092 m of near-continuous vertical from 810 m to 1902 m. Respect the numbers, pace to your threshold, and gear low — and this monster becomes a summit worth savouring.

Length: 11.7 km
Average gradient: 9.32%
Max gradient: n/a
Start: 810 m
Summit: 1902 m
Net gain: 1092 m
Total ascent: 1039 m
Category: HC