Col des Ares

Overview

The Col des Ares sits in the French Pyrenees as a Category 3 climb — on paper, one of the more accessible passes in the region. The numbers back that up to a point: 10.2 km from base to summit, an average gradient of 3.86%, and a total ascent of 532 m over a start elevation of 416 m. Those figures suggest a manageable day out. What they obscure is a maximum gradient of 22.89%, a number that changes the character of this climb entirely.

How the Gradient Unfolds

The Col des Ares is not a climb that punishes you from the first pedal stroke. The lower slopes are genuinely forgiving, with the average gradient of 3.86% reflecting long stretches of moderate road that allow riders to settle into a rhythm and preserve glycogen stores for later.

The danger is in that rhythm. Because much of the climb feels unthreatening, it is easy to push a gear or two larger than the terrain demands, running a deficit that compounds badly when the road kicks up. And it does kick up — sharply. The maximum gradient of 22.89% is not a sustained ramp but it is steep enough to bring even well-paced riders to a near standstill if they arrive there with tired legs or an overgeared setup.

Key Gradient Phases

• Lower section: Consistent, moderate slopes. Use this to establish a sustainable power output relative to your FTP — around 70–75% is a reasonable ceiling here.
• Mid-section: Gradients remain variable but manageable. Avoid the temptation to accelerate; save matches for what follows.
• Upper ramps: The maximum 22.89% gradient sections demand a low gear and controlled cadence. Spiking effort here after an aggressive lower climb is the most common mistake on this road.

Pacing Notes

The 3.86% average is deceptive as a pacing guide because it smooths over the gradient variance significantly. Treat this climb as two separate efforts: a tempo-paced lower section and a genuinely steep upper push.

For pacing strategy, reference your FTP and target a normalized power that reflects the spiky nature of the gradient rather than chasing a flat average-speed target. If you don't have a current FTP figure, the FTP estimator can give you a working baseline before you head out.

Gearing Recommendations

Do not underestimate the 22.89% maximum gradient. For riders on standard road gearing (typically 34-tooth inner chainring), a cassette with at least a 32-tooth sprocket is advisable. Compact or semi-compact setups with a wide-range cassette will handle the steep ramps without forcing you out of the saddle under duress.

If you are climbing with loaded bags or heavier than race weight, err toward the widest range cassette available on your drivetrain. At 22.89%, there is no comfortable gear to grind through — only a gear low enough to maintain cadence and one that isn't.

Summary

The Col des Ares is a Category 3 climb that rewards patience and punishes complacency. Its 10.2 km length and 3.86% average gradient make it look straightforward on a segment profile. The 22.89% maximum gradient tells a different story. Ride the bottom conservatively, keep a compact gear on hand, and treat the upper slopes as the climb's true test.