Paso de los Leones

Paso de los Leones cycling climb profile

Paso de los Leones is an HC climb in Chile that looks manageable if you only read the average gradient, then becomes a very different problem once the full profile is considered. The climb is 93.3 km long, starts at 519 m, and tops out at 3918 m, with 3399 m of net elevation gain and 3785 m of total ascent.

That combination matters. An average gradient of 3.65% across this distance does not describe a steady, tempo-friendly alpine road. It describes a very long uphill route where the headline gradient is diluted by easier ground, possible flatter sections, and elevation that is given back before being gained again. The total ascent being higher than the net gain is the giveaway: this is not simply one clean ramp from bottom to summit.

How the gradient unfolds

With the available data, the safest way to read Paso de los Leones is as a climb of accumulation rather than a climb defined by one constant slope. The road gains a massive amount of height from 519 m to 3918 m, but the 3.65% average suggests the gradient repeatedly relaxes enough to pull the overall number down.

The danger is that those easier sections can make the climb feel deceptively controlled early on. The maximum gradient of 32.36% shows the opposite side of the profile: there are pitches steep enough to force a change in cadence, gearing, and effort whether the rider wants it or not. On a climb this long, those ramps are not just isolated discomfort. They are matches burned inside an already expensive day.

The final outcome is a climb where pacing errors compound. A rider who treats the average gradient as the target effort can end up over-riding the steep sections, coasting too little on the easier ground, and arriving late in the climb with no torque left for the hardest ramps.

Pacing and gearing notes

Ride this by effort, not by average speed. The length and total ascent make it a durability test first, while the maximum gradient makes it a gearing test second. If using power, the early strategy should sit clearly below /glossary/ftp, because the climb gives plenty of opportunity to spend energy later whether planned or not.

Gearing should be chosen for the maximum gradient, not the average gradient. An easy climbing setup is the sensible call, because a 32.36% pitch does not care that the full climb averages 3.65%. Spinning smoothly through the lower-gradient portions and protecting cadence on the steepest ramps will beat grinding early and hoping to recover higher up.

The key to Paso de los Leones is respecting the mismatch between the average and the extremes. It is long enough to punish impatience, high enough in total gain to reward restraint, and steep enough at its maximum to expose any rider who under-gears or over-paces the first half.