Coll de Guilló

Overview

Coll de Guilló is a category 2 climb that rewards patience over punch. Across 18.8 km it lifts you from a start elevation of 269 m to a 988 m summit, a net gain of 719 m. The average gradient sits at a modest-sounding 3.82%, which places it firmly in the long-and-steady mould rather than the leg-snapping wall camp. But the average hides the story: with a maximum pitch of 12.76%, this is not a climb you can simply switch off and grind. The total ascent of 711 m sits just below the net figure, a hint that the road tips downward here and there before clawing the elevation back.

How the Gradient Unfolds

The gap between the 719 m net gain and the 711 m of total ascent tells you the profile is not perfectly monotonic — there are false flats and small dips where you recover, then repay. At 3.82% average over 18.8 km, most of the road is gentle enough to hold a rhythm and even big-ring it in stretches. The danger is complacency. Somewhere on the ascent the gradient spikes to 12.76%, more than three times the average, and those ramps arrive as brief, sharp reminders. Read the road ahead: shift early before each pitch rather than being caught in too tall a gear when the surface kicks up.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to your FTP and aim to sit just under threshold on the shallow sections, spending your matches only on the 12.76% ramps where staying seated and smooth costs less than surging out of the saddle. If you do not know your threshold number, run the numbers through the FTP estimator before you ride so your target wattage is grounded rather than guessed. With 18.8 km to cover and 719 m to gain, going too deep in the first third leaves nothing for the steepest pitches — bank patience early, spend late.

Gearing

For a 3.82% average you do not strictly need extreme gearing, but the 12.76% maximum changes the calculation. A compact 34-tooth chainring paired with a wide cassette gives you the escape hatch you want on the ramps. A 34×32 will carry most fit riders through the steep sections with a workable cadence, and it is the sensible baseline for anyone comfortable on category 2 terrain. If you weigh more, climb on tired legs, or simply prefer to spin, step up to a 34×34 — that extra sprocket keeps your cadence alive at 12.76% and protects your knees over the full 18.8 km. Either way, err toward easier: on a long climb, spare gears cost nothing and buy everything.

Summary

Coll de Guilló is a long, rhythmic category 2 ascent with a deceptively gentle average and a genuine sting in its steepest ramps. Pace it to your threshold, gear it for the 12.76% pitches, and let the 3.82% average do the rest over 18.8 km.

Length: 18.8 km
Average gradient: 3.82%
Max gradient: 12.76%
Start: 269 m
Summit: 988 m
Net gain: 719 m
Total ascent: 711 m
Category: 2