Col de Portel

Overview

Col de Portel is a Category 1 climb in France, running 16 km from a start elevation of 414 m to a summit at 1,430 m. On paper it delivers a net elevation gain of 1,016 m at an average gradient of 6.35% — a serious, sustained effort that sits firmly in the upper tier of categorized climbs.

The average, however, undersells the work. The road climbs a net 1,016 m but racks up 1,672 m of total ascent, meaning roughly 656 m of that gain is repaid and re-earned across descents and rollers along the way. That undulation matters: you cannot simply settle into one rhythm and grind to the top. Every dip forces you to spin back up to speed, and every re-ascent chips at legs that a smoother 6.35% profile would spare.

How the Gradient Unfolds

A 6.35% average is a smoothing lie on a climb like this. With pitches reaching 22.86%, the real ride swings hard between recovery and near-standstill. Expect the gradient to lurch rather than build steadily, so read the road ahead rather than trusting the number on your head unit.

• Flatter and downhill sections where the profile gives back part of its gain — these are the 656 m of extra ascent in the making
• Repeated short climbs stacked between the dips, each demanding a fresh surge of effort
• A brutal steepest ramp touching 22.86%, well into out-of-the-saddle, torque-limited territory

Pacing Notes

On a smooth climb, even-effort and even-speed pacing nearly converge. On Col de Portel's broken profile they diverge sharply. Chasing an even speed here means over-cooking the 22.86% ramps and coasting the descents — a recipe for blowing up. Instead, hold an even effort just under your sustainable power output, letting speed rise on the shallow sections and fall on the steep ones without spiking your power.

Practically: cap your surges on the steepest pitches to a brief, controlled overshoot, then recover on the flatter and descending sections rather than pressing. If you don't know your ceiling, run the numbers through the FTP estimator before you commit to a target.

Gearing

The 22.86% maximum gradient governs your setup, not the average. Bring a compact (50/34) or, better, a sub-compact chainset paired with a wide-range cassette — think 34×32 or 34×34 — so you can keep a turning cadence when the road stands up. Undergeared, you'll be mashing at 40 rpm and burning matches you'll want later on the re-ascents. Check your chainrings and cassette before the ride; discovering you're overgeared halfway up a 22.86% wall is not a fixable problem on the road.

Summary

• Length: 16 km
• Average gradient: 6.35%
• Maximum gradient: 22.86%
• Net elevation gain: 1,016 m
• Total ascent: 1,672 m
• Category: 1

Col de Portel is a Category 1 climb that punishes riders who read only the average. Respect the 656 m of hidden re-climbing, gear low for the 22.86% ramps, and pace to effort rather than speed — and the 16 km to the 1,430 m summit becomes a hard day well ridden rather than a blow-up.