Collada de Fontalba

Overview

The Collada de Fontalba is a long, patient climb rather than a short, explosive one. Over 24.5 km the road lifts you from a start elevation of 694 m to a summit at 2087 m, a net gain of 1393 m spread across an average gradient of 5.69%. That average is friendly on paper, but the total ascent of 1376 m tells you the road rarely lets you coast — you are working almost the entire way up. Rated category 1, it sits one rung below hors catégorie, which is exactly what the length and altitude gain suggest: a serious, sustained effort that rewards riders who can hold a steady tempo for well over an hour.

How the Gradient Unfolds

The headline figure is deceptive in the way most long climbs are. A 5.69% average across 24.5 km means long stretches sit close to that number, but the maximum gradient of 29.53% warns that at least one ramp is brutally steep — roughly five times the average. Expect the climb to breathe: shallower valley-floor kilometres near the 694 m base give way to steeper middle and upper sections as you push toward 2087 m. The gap between the net gain of 1393 m and the total ascent of 1376 m is small, so there is very little descending mixed in — this is an almost relentlessly upward road, with the sharpest pitch a spike you must survive rather than a sustained wall.

Pacing Notes

On a climb this long, pacing is everything. Aim to sit just below your threshold for the sustained sections and save a reserve for that 29.53% pitch, which will spike your power far above FTP no matter how disciplined you are. If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target. Because the average is a manageable 5.69%, the temptation is to start too hard on the gentler lower slopes — resist it. Bank effort for the upper third, where thinning air above 2000 m and accumulated fatigue over 24.5 km will quietly erode your output. Ride the steady kilometres at a rhythm you could sustain indefinitely, then dig in only where the road pitches up.

Gearing

For a 24.5 km climb averaging 5.69% with a 29.53% maximum, gearing generosity is not weakness — it is strategy. A compact chainring paired with a wide-range cassette is the sensible baseline. A 34×32 will carry most riders through the sustained 5.69% sections comfortably, but the near-30% ramp is where a 34×32 can leave you grinding and overgeared. If your legs or your altitude tolerance are in any doubt, fit a 34×34: the extra sprocket keeps your cadence alive on the steepest pitch and protects your knees across the full 1376 m of ascent. Lower is almost always the right call on a climb this long.

Summary

The Collada de Fontalba is a rider's climb: long, high, and honest. Respect the 24.5 km distance, meter your effort against the 5.69% average, and keep something in the tank for the 29.53% sting near the top. Steady legs and low gearing turn this category-1 giant from an ordeal into a genuinely satisfying day out.

Length: 24.5 km
Average gradient: 5.69%
Max gradient: 29.53%
Start: 694 m
Summit: 2087 m
Net gain: 1393 m
Total ascent: 1376 m
Category: 1