Collada de Prats

Overview

Collada de Prats is a Category 2 climb in France, running 13.4 km from a start elevation of 948 m to a summit of 1599 m. On paper that gives a net elevation gain of 651 m, which sounds modest for the distance. It is the kind of climb that looks straightforward in a road book and reads very differently under the tires.

The reason is the gap between net gain and total ascent. You gain 651 m from bottom to top, but the total ascent over the climb is 1364 m — an extra 713 m of climbing you pay for through dips and re-ascents along the way. That undulation means the road repeatedly gives elevation back and makes you earn it again, so the effort is meaningfully harder than the 651 m net figure suggests. Budget for a longer, punchier day than the numbers first imply.

How the Gradient Unfolds

The 4.86% average is an accountant's number, not a rider's. With 1364 m of total ascent packed into 13.4 km, the real climbing is concentrated into ramps far steeper than 4.86%, separated by flatter and downhill stretches that drag the average down.

• Flatter and recovery sections where the road eases or tips downhill, resetting the average
• Repeated short climbs that force you back onto the pedals after each dip
• A steepest ramp hitting 22.87% — a genuine wall that demands its own gear

Do not let the early flat kilometers lull you into overspending before the pitches arrive.

Pacing Notes

On a smooth climb you can hold even effort and let speed drift with the slope. Here, the undulation punishes that instinct: chase even speed and you will spike your power on every ramp and blow up. Instead, anchor to even effort — hold your sustainable power output through the steep sections and accept that you will feel slow, then relax on the descents rather than hammering to hold a number.

If you do not know your ceiling, run the FTP estimator first and pace the ramps a notch below it, leaving headroom for the repeated re-accelerations.

Gearing

The steepest gradient governs your setup, and 22.87% is what you gear for. A compact (50/34) or sub-compact chainset paired with a wide-range cassette — 34×32 or 34×34 at minimum — keeps your cadence alive on the wall instead of grinding to a standstill. Check your chainset and cassette before you ride; you do not want to discover you are over-geared halfway up a 22% pitch with nowhere to spin.

Summary

• Length: 13.4 km
• Average gradient: 4.86%
• Maximum gradient: 22.87%
• Net elevation gain: 651 m
• Total ascent: 1364 m
• Category: 2

Collada de Prats rewards riders who respect the difference between its 651 m net gain and 1364 m of total ascent. Gear for the steep ramp, pace by effort, and treat the average gradient as a lie the profile tells.