Paso de Los Patos

Paso de Los Patos cycling climb profile

Paso de Los Patos is an HC climb because the difficulty is not concentrated in one obvious place. It is 72.7 km long, starts at 756 m, and reaches 4144 m, with 3388 m of net elevation gain. The average gradient is 4.66%, which can look controlled on paper, but that number is spread across an unusually long climb and hides a maximum gradient of 24.93%.

That combination matters. A moderate average over this distance encourages riders to settle too close to tempo early, then discover that the real cost is not one steep wall, but the long accumulation of climbing, altitude, and repeated changes in resistance.

How the gradient unfolds

The cleanest way to read Paso de Los Patos is as a sustained high-mountain ascent with interruptions in rhythm. Total ascent is 3651 m, which is greater than the 3388 m net gain, so the road is not simply a smooth ramp from bottom to summit. There is enough extra climbing beyond the net elevation change to suggest undulation, short losses of height, or sections where the gradient eases before forcing the rider to climb again.

This makes the 4.66% average a little deceptive. On a perfectly even climb, that would point to a steady aerobic effort. Here, the listed maximum of 24.93% changes the character. Even if those steepest ramps are brief, they force torque spikes, cadence disruption, and possible out-of-saddle efforts. The climb is therefore less about holding one elegant number and more about keeping the effort controlled every time the road asks for more than the average suggests.

The upper part also has a different physiological feel because the summit is at 4144 m. Pacing mistakes made lower down become more expensive as the climb goes on, not because the gradient necessarily has to steepen, but because recovery becomes harder while the elevation continues to rise.

Pacing and gearing notes

Treat the opening of Paso de Los Patos as a restraint test. The climb is long enough that anything above sustainable endurance or low-tempo pressure early can become a liability later. If riding to /glossary/ftp, cap the surges on steeper ramps rather than trying to defend speed. The goal is to keep power and breathing stable when the gradient briefly stops cooperating.

Gearing should be chosen for the 24.93% maximum, not the 4.66% average. A setup that feels efficient on the gentler sections may leave too little margin when the road pitches up. Prioritize a low climbing gear that lets you stay seated and keep traction when fatigue is already present.

The practical strategy is simple: under-ride the average early, absorb the steep ramps without going deep, and save enough control for the long drag to 4144 m. Paso de Los Patos rewards riders who respect the full 72.7 km rather than reacting only to the gradient in front of them.