Puerto de las Carreteras

Overview

Puerto de las Carreteras is a Category 2 climb in Spain (ES), running 16.9 km from a valley floor to an exposed summit. It gains 821 m net over its length, starting at 205 m and topping out at 1,026 m. On paper the 4.86% average gradient reads as steady tempo work, the kind of number that suggests a rider can settle in and grind to the top without drama.

That reading is misleading. The climb records 1,606 m of total ascent against only 821 m of net gain — a difference of 785 m that never counts toward the summit. Those meters are spent climbing rollers you then give back on the descents between them. This is an undulating road, not a single sustained wall, and it means your legs do nearly twice the vertical work the elevation profile implies. Budget for it.

How the Gradient Unfolds

The 4.86% average is a blend of false flats, short descents, and sharper ramps stacked on top of each other. Because 785 m of the total ascent is undulation, long stretches sit well below average — and the pitches that do bite sit well above it. Treat the average as an accounting figure, not a description of any single kilometer.

• Flatter and recovery sections where the road drops or levels between rollers, giving back elevation you have to re-climb
• Repeated short climbs that stack into the total ascent without moving the net gain much
• The steepest ramps, which force you well over the average and spike your power if you meet them in the wrong gear

Pacing Notes

On a climb this lumpy, chasing an even speed is a trap — you will torch your legs surging over every roller. Pace to an even effort instead, holding a steady sustainable power output and letting your speed rise and fall with the terrain. Ease slightly on the recovery dips rather than hammering to "make up time," then meter your power over the ramps.

Know your ceiling before you start. Run the FTP estimator and set a target you can hold across all 16.9 km and the full 1,606 m of climbing — not just the net 821 m the summit suggests.

Gearing

With ramps that climb well above the 4.86% average, gear for the steep pitches, not the mean. Fit a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 low gear lets you keep cadence up and stay seated where the road bites. Confirm your chainset and cassette before the ride; discovering you have spun out your easiest gear mid-ramp is a mistake you only make once.

Summary

• Length: 16.9 km
• Average gradient: 4.86%
• Net elevation gain: 821 m
• Total ascent: 1,606 m
• Category: 2

Puerto de las Carreteras is a deceptive Category 2. The average gradient sells it short — the 785 m gap between net gain and total ascent is where the day is actually won or lost. Pace to effort, gear for the ramps, and respect the rollers.