Alto de los Colorados

Alto de los Colorados cycling climb profile

Alto de los Colorados is a category 1 climb that looks manageable on average, but the numbers make it clear why it needs respect. The ascent is 15.3 km long at an average gradient of 5.85%, rising from 3709 m to 4606 m for 897 m of net elevation gain.

That combination matters. A 5.85% average over this length is not a pure wall, so the climb is likely to reward rhythm more than repeated accelerations. But the maximum gradient of 16.61% changes the pacing equation. The average does not tell the full story when the steepest pitch is nearly three times the overall grade. Even if the harshest section is short, it is steep enough to force a real torque spike if the gearing is too big or the effort is already too close to the limit.

How the gradient rides

From the bottom, the key feature is not just the slope, but where the climb begins. Starting at 3709 m means there is no easy physiological entry point. The opening effort should be treated as part of the climb immediately, not as a warm-up before the hard work starts.

Across the full 15.3 km, the 5.85% average suggests a sustained, aerobic ascent where speed will fluctuate less from tactics and more from how well the rider keeps pressure on the pedals. The 897 m of net gain is spread over enough distance that the climb can be ridden seated for long periods, but the 16.61% maximum warns against assuming it is steady all the way to the summit.

With no segment-by-segment gradient data available, the honest way to read this climb is as a long high-altitude effort with at least one severe ramp embedded inside it. That means the decisive mistake is not losing a few seconds on the steepest pitch. It is arriving there already over threshold, then being forced into a gear and cadence that drives the effort further out of control.

Pacing and gearing notes

Ride the first part conservatively. If using power, anchor the effort below your normal sea-level climbing target and avoid chasing speed early. At this elevation, a familiar /glossary/ftp effort can feel more costly, and the penalty for going too deep arrives quickly.

Gearing should be chosen for the maximum gradient, not the average. A setup that feels fine at 5.85% may become inefficient on a 16.61% ramp. The priority is having a low enough gear to stay seated, keep cadence from collapsing, and avoid turning the steepest section into a strength effort.

The best ride here is controlled rather than heroic: settle into the average grade, save a small reserve for the steepest pitch, then use the final altitude gain to judge the effort rather than the clock.