Coll de Prunera

Overview

Coll de Prunera is a long, patient climb rather than a violent one. Across 22.1 km it lifts you from a valley floor at 108 m to a summit at 843 m, a net gain of 735 m. On paper the average gradient of 3.32% reads as gentle, and for long stretches it genuinely is — but that number hides a maximum pitch of 12.62%, so this is not a climb you can switch off on. The category 2 rating captures that tension: substantial in length and vertical, yet never sustained enough to tip into the harshest brackets. Note that the total ascent of 692 m sits slightly below the net gain of 735 m, which tells you the road climbs almost relentlessly with little in the way of descending relief along the way.

How the Gradient Unfolds

The defining feature of Prunera is the gap between its average and its maximum. A 3.32% mean spread over 22.1 km means the bulk of the road is shallow, the kind of grade you can hold in a big gear at tempo. But the 12.62% max is more than three and a half times steeper than that average, so the difficulty is concentrated in short, sharp ramps that punctuate the long false flats. Expect a rhythm of easy drags interrupted by sudden pinches. Because the summit sits at 843 m — a 735 m rise from the start — the climb keeps gaining height the whole way, but it does so unevenly. Read the road ahead: the steep sections are where the climb is genuinely won or lost, and everything between them is recovery.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to your FTP: on the shallow 3.32% sections, aim to sit just below threshold and let the low grade carry you, then accept a controlled surge above FTP through the 12.62% ramps rather than trying to hold a flat power number. Blowing up on an early pitch costs you far more over 22.1 km than easing off ever would. If you're unsure of your threshold, run the numbers through the FTP estimator before you commit to a target, and pace the first third conservatively — you still have most of the 735 m of climbing ahead of you.

Gearing

For most riders the shallow average is deceptive; it's the 12.62% ramps that dictate your gear choice. A compact 34-tooth chainring paired with a 34×32 low gear is a sensible baseline and will spin most of the climb comfortably. If you climb seated, favour a lighter gear, or expect to be tired after 22.1 km of near-continuous ascent, step up to a 34×34 — the extra sprocket keeps your cadence alive on the steepest pitches without forcing you out of the saddle. Given the length and the near-total 692 m of grinding, err toward the easier option; there's no penalty for spinning.

Summary

Coll de Prunera rewards patience: a long category 2 climb with a friendly average and a genuine sting in its steepest ramps. Pace it to your threshold, gear for the pinches, and let the 22.1 km come to you.

Length: 22.1 km
Average gradient: 3.32%
Max gradient: 12.62%
Start: 108 m
Summit: 843 m
Net gain: 735 m
Total ascent: 692 m
Category: 2