Cerro Alto Nahuelbuta

Overview

Cerro Alto Nahuelbuta is a Category 1 climb that asks a serious, sustained effort of anyone who takes it on. Over 9.9 km it averages 7.01%, lifting you from a start elevation of 338 m to a summit at 1035 m — a net gain of 697 m. The total ascent of 666 m confirms this is a climb that rarely lets up: there is very little rolling relief to hand back altitude, so almost every metre you gain, you keep. With a maximum gradient of 18.24%, it also has teeth. This is a climb defined by its length and its steady, relentless slope rather than by any single feature.

How the Gradient Unfolds

The headline number is the 7.01% average, but averages flatten the story. On a climb of 9.9 km, a 7% mean gradient means you are spending most of the effort somewhere between the high single digits and low double digits, punctuated by pitches that spike toward the 18.24% maximum. The gap between the 7.01% average and the 18.24% max is the crux of pacing here: those steep ramps are roughly two and a half times harder than the average, and hitting them cold or over-geared will hurt. The near-equal net gain (697 m) and total ascent (666 m) tell you the profile climbs almost monotonically — there are no meaningful descents to recover on. Plan for a continuous, grinding effort from bottom to top.

Pacing Notes

Treat Nahuelbuta as a threshold climb. At 9.9 km, most riders will be on the road for well over half an hour, so pace it against your sustainable power rather than your ego. A good rule is to settle just under your FTP for the bulk of the 7.01% sections and reserve headroom for the steep ramps toward 18.24%, where you will briefly exceed threshold whether you like it or not. If you do not know your threshold number, run your recent data through the FTP estimator before you attempt this — the difference between a well-paced ascent and blowing up on a Category 1 climb almost always comes down to knowing that one figure. Start conservatively; the climb is long enough to punish an aggressive opening.

Gearing

Do not under-gear this climb. With ramps reaching 18.24% and an overall average of 7.01% held across 9.9 km, you want a low bailout gear that lets you keep cadence up without grinding your knees. A compact 34-tooth chainring paired with a 32-tooth cassette sprocket — 34×32 — is the sensible minimum for most riders here. If you carry any fatigue, ride at moderate fitness, or simply want to spin the steep pitches rather than muscle them, step up to 34×34. On a climb with 666 m of total ascent and no recovery, the easier gear pays for itself over the full 9.9 km.

Summary

Cerro Alto Nahuelbuta is a proper Category 1 test: long, steep, and unbroken. Respect the 18.24% ramps, pace against threshold, and gear low enough to keep spinning to the 1035 m summit.

Length: 9.9 km
Average gradient: 7.01%
Max gradient: 18.24%
Start: 338 m
Summit: 1035 m
Net gain: 697 m
Total ascent: 666 m
Category: 1