Alto de Collai

Alto de Collai cycling climb profile

Alto de Collai is a compact but demanding climb in Chile, measuring 3 km at an average gradient of 10.19%. That combination matters. This is not a long climb where the damage comes from duration. It is a short, high-pressure effort where the gradient is hard enough from the outset that pacing errors show up quickly.

The climb starts at 864 m and tops out at 1171 m, with a listed net elevation gain of 307 m. Over only 3 km, that vertical gain explains why the average gradient is already in double digits. The maximum gradient of 12.9% is not wildly above the average, which suggests the difficulty is less about one isolated wall and more about sustained steepness. In practical terms, the hard sections are not interruptions to an otherwise manageable climb. They are part of the climb's normal rhythm.

How the gradient rides

With an average of 10.19%, Alto de Collai should be treated as steep from bottom to summit. There is not enough length for a patient diesel rhythm to fully rescue a bad opening, and there is not enough statistical softness in the profile to assume meaningful recovery. Even if the road varies slightly, the headline numbers point to a climb that keeps pressure on the pedals almost continuously.

The 12.9% maximum gradient is important because it will likely force torque spikes if you are under-geared or already riding above threshold. On a climb this short, it is tempting to attack the bottom and absorb the cost later. That is usually the wrong read. The average gradient is already severe, so going too deep early can turn the upper part into a low-cadence survival effort rather than a controlled climb.

Pacing and gearing notes

Ride the opening below your instinct. On a 3 km climb, the time cost of starting slightly controlled is small, while the penalty for blowing up on double-digit gradients is large. Aim to keep the first part smooth, stay seated where possible, and save standing efforts for the steepest ramps or for resetting cadence.

Gearing should prioritize cadence preservation, not speed. Because the climb averages 10.19% and reaches 12.9%, an easy climbing gear is not optional for most riders. If your gearing forces you into grinding early, the climb will become muscular before it becomes aerobic, and that raises the risk of fading before the summit.

For riders pacing by power, this is the type of climb where knowing your /glossary/ftp matters, but execution matters more. A controlled threshold-style start, followed by a harder finish if the legs are still responsive, is the safer strategy than chasing speed from the base. Alto de Collai is short, but its steepness makes it honest.