Coll des Prat

Overview

Coll des Prat is a category 1 climb that asks a serious question of your legs the moment the road tilts. Over 12.1 km it averages 7.32%, lifting you from a start elevation of 322 m to a summit at 1208 m. That is 886 m of net elevation gain, with a total ascent of 894 m once the small dips and rolls along the way are counted. Category 1 sits just below hors catégorie, the hardest tier, and this climb earns its ranking honestly: long enough to burn a real hole in your reserves, and steep enough to punish anyone who starts too hard.

How the Gradient Unfolds

The headline number, 7.32%, is an average, and averages hide as much as they reveal here. The defining feature is a maximum gradient of 31.61% — a wall so steep it barely qualifies as a road gradient at all, the kind of ramp where momentum evaporates and you are suddenly grinding at walking pace. Because that spike is so extreme, the remaining kilometres must sit below the 7.32% mean to balance it out, meaning long stretches of steady, sustainable climbing punctuated by sharp escalations. Read the road as two climbs stitched together: the aerobic grind you can settle into, and the anaerobic punches you have to survive. The 894 m of total ascent versus 886 m net tells you the profile is not perfectly relentless — there are brief reliefs, roughly 8 m of give-back across the whole ascent, but do not expect them to save you.

Pacing Notes

Pace this one off your sustainable power, not your ego. Anchor your effort to your FTP and hold something in reserve for that 31.61% ramp, where you will spike well over threshold no matter how disciplined you have been. If you do not know your number, run the FTP estimator first, then target the long 7.32% sections at a controlled sub-threshold effort. The trap is the opening kilometres: fresh legs feel invincible, but with 886 m still to climb, an early overreach compounds into a slow-motion blow-up higher up. Settle in, breathe, and treat the steep pitches as spikes to absorb rather than efforts to win.

Gearing

Gear for the wall, not the average. A 34×32 bottom gear is the sensible minimum for a 12.1 km climb at 7.32%, and it will get most riders up the steady sections comfortably. But the 31.61% maximum changes the math entirely — on a ramp that severe, you want every tooth you can find. A 34×34 gives you meaningful extra range for that pitch, keeping your cadence off the floor and your knees intact. If your frame and derailleur clear it, choose the 34×34 for this climb. The extra range costs you nothing on the shallower kilometres and buys you survival on the steepest.

Summary

Coll des Prat is a long, honest category 1 effort defined by one extraordinary ramp. Respect the 31.61% max, gear low, pace off your threshold, and let the 886 m of climbing come to you.

Length: 12.1 km
Average gradient: 7.32%
Max gradient: 31.61%
Start: 322 m
Summit: 1208 m
Net gain: 886 m
Total ascent: 894 m
Category: 1