Belen Pass

Overview

Belen Pass is a long, steady category 2 climb that rewards patience over explosiveness. Across 14.3 km it lifts you from a start elevation of 32 m to a 717 m summit, a net gain of 685 m. The average gradient sits at a manageable 4.79%, but the total ascent of 683 m confirms this is sustained work rather than a quick effort. The headline number to respect is the 9.51% maximum gradient — proof that the road does bite in places, even if the overall profile stays civil.

How the Gradient Unfolds

With a 4.79% average stretched over 14.3 km, Belen Pass is best understood as a rhythm climb. Long stretches hover near or just above that mean, which lets you settle into a repeatable cadence and hold it. The story of the climb, though, is in the spread between the 4.79% average and the 9.51% maximum. That gap of roughly 4.72 percentage points tells you the gradient is not uniform: expect shallower ramps where you can recover interspersed with steeper kicks approaching double digits. Because 683 m of the 685 m net gain comes as almost pure climbing, there is little in the way of false flat or descent to break the effort — you keep grinding upward from 32 m all the way to 717 m.

Pacing Notes

On a climb this length, discipline early pays off late. Pin your effort to your FTP and aim to ride the 4.79% sections just under threshold so you have headroom for the pitches nearing 9.51%. Let the steep ramps push your power up briefly, then ease back onto the shallower gradients to bring your heart rate down before the next kick. If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target. Starting too hard on the lower slopes near 32 m is the classic error here — with 685 m of climbing ahead, the last kilometres to the 717 m summit are where a conservative first half turns into a strong finish.

Gearing

For a 14.3 km climb averaging 4.79% with ramps to 9.51%, give yourself room to spin. A compact chainring paired with a wide-range cassette is the sensible baseline. A 34×32 will get most riders over the steeper 9.51% sections without grinding, but if you want extra insurance for tired legs late on, step up to a 34×34 so you can keep your cadence smooth all the way to 717 m. Preserving cadence over the full 685 m of climbing matters far more than pushing a big gear on the shallower stretches.

Summary

Belen Pass is a sustained category 2 effort: 14.3 km of climbing, a 4.79% average, and a 9.51% maximum, gaining 685 m from base to summit. Ride it with a compact gear and a threshold-aware pacing plan, and it becomes a satisfying rhythm climb rather than a struggle.

Length: 14.3 km
Average gradient: 4.79%
Max gradient: 9.51%
Start: 32 m
Summit: 717 m
Net gain: 685 m
Total ascent: 683 m
Category: 2