Paso de Buta Mallín

Paso de Buta Mallín cycling climb profile

Paso de Buta Mallín is a category 3 cycling climb in Argentina: 8.7 km at an average gradient of 4.47%, starting at 1,388 m and topping out at 1,775 m. On paper, that average makes it look manageable. The important detail is the maximum gradient of 14.4%, because that changes how the climb should be ridden.

This is not a pure steady-state diesel climb where the average tells the whole story. An 8.7 km ascent with a 4.47% average and a 14.4% maximum has to contain contrast. The climb gives back enough easier gradient to keep the overall number moderate, but the steepest ramps are hard enough to punish riders who pace it like a smooth tempo effort from bottom to summit.

How the gradient unfolds

From the start elevation of 1,388 m, the climb gains 387 m net by the summit at 1,775 m. Across 8.7 km, that creates a profile that should feel aerobic for long stretches, then suddenly muscular when the road kicks up.

The practical interpretation is simple: the average gradient is your endurance reference, but the max gradient is your gearing reference. The 4.47% average suggests much of the climb can be handled seated and controlled. The 14.4% maximum says there are moments where cadence can collapse if you arrive overgeared or already above threshold.

That combination usually makes the climb harder than the headline average implies. Riders tend to see a sub-5% average and settle into a gear that feels efficient early. The problem is that when the steep ramps arrive, the cost of forcing the same gear rises sharply. That is where the climb can turn from controlled tempo into repeated anaerobic spikes.

Pacing and gearing notes

Treat Paso de Buta Mallín as a climb to ride by discipline, not ego. The opening effort should feel comfortably below threshold, especially if you are pacing from /glossary/ftp. There is enough length here for early over-pacing to matter, but not so much length that you need to ride defensively the whole way.

A good approach is:

• Start at a sustainable aerobic effort, not the effort the average gradient tempts you into.
• Shift early before the steepest ramps, because the 14.4% maximum is the number that can break cadence.
• Stay seated where possible to keep traction and limit surges, then use short standing efforts only to get over the sharpest pitches.
• Build the effort after the hardest ramps are managed, rather than spending energy trying to accelerate into them.

For gearing, choose the setup for the steepest part, not the average. A rider who can spin comfortably through the ramps will preserve momentum and avoid unnecessary torque spikes. That matters on a climb like this because the moderate average gives chances to recover, but only if the steep sections have not already pushed the effort too far into the red.

The cleanest way to ride Paso de Buta Mallín is to respect the hidden difficulty: steady on the moderate gradients, conservative before the ramps, and decisive only when the summit is close enough that the remaining cost is clear.