Alto de Vacas - Troncal Central

Overview

The Alto de Vacas via the Troncal Central is a long, relentless Category 1 ascent that asks for patience before it asks for power. From a valley floor at 468 m, the road unwinds across 22.2 km to a summit at 1663 m — a net gain of 1195 m at an average gradient of 5.38%. That average is honest but deceptive: with a total ascent of 1250 m logged against 1195 m of net gain, there are dips and false flats folded into the profile, meaning the climbing sections are steeper than the headline number suggests. This is a climb measured in ten-minute blocks, not heroics.

How the Gradient Unfolds

A 5.38% average over 22.2 km sounds like a rhythm climb, and for long stretches it is. But the 28.52% max gradient is the number that reshapes how you ride it. A wall that steep — more than five times the average — cannot be spread evenly; it lives in a short, brutal pinch that will spike your heart rate and blow your cadence apart if you meet it in the wrong gear. Between those pinches, expect grades that sit around or just below the 5.38% mean, with the extra 55 m of total ascent over net gain confirming there are recovery dips where the road briefly gives back before climbing again. Read the road: cruise the shallow sections, respect the ramps.

Pacing Notes

On a climb this long, discipline beats ambition. Anchor your effort to your FTP and hold the shallow kilometres a touch under threshold so you have something left when the gradient bites. If you do not know your current number, run the FTP estimator before you commit to a target — riding 22.2 km blind is how a strong day turns into a slow-motion detonation. Treat the 28.52% pinch as a separate event: shift early, get out of the saddle briefly if you must, and accept that you will go over threshold there. The goal is to bleed as little time as possible on the wall, then settle straight back into your climbing rhythm rather than chasing lost seconds.

Gearing

Gear for the wall, not the average. A 34×32 lowest ratio is the sensible floor here — it will carry you through the 5.38% majority comfortably — but the 28.52% max gradient argues strongly for a 34×34. That extra sprocket is the difference between spinning over the steepest pinch and grinding to a near-stall with 1195 m already in your legs. Over 22.2 km, protecting your cadence protects your whole ride, so err toward the easier 34×34 unless you know your climbing legs are exceptional.

Summary

Alto de Vacas - Troncal Central is a Category 1 endurance test: long, mostly steady, but stamped with one savage ramp that dictates your gearing and your nerve. Pace the shallow kilometres, respect the wall, and let the summit at 1663 m come to you.

Length: 22.2 km
Average gradient: 5.38%
Max gradient: 28.52%
Start: 468 m
Summit: 1663 m
Net gain: 1195 m
Total ascent: 1250 m
Category: 1