Doroñu mendatea / Portillo del Reventón

Overview

Doroñu mendatea, also signed as Portillo del Reventón, is a short, honest category-4 climb. It runs 4.9 km from a base at 622 m to a summit at 830 m, a net gain of 208 m. The average gradient sits at a gentle 4.24%, and the steepest ramp tops out at 6.99% — never truly severe, but steady enough to keep you working. With a total ascent of 188 m over its length, this is a climb you can measure, plan for, and ride cleanly if you pace it well.

How the Gradient Unfolds

The shape here is straightforward and rewarding. A 4.24% average across 4.9 km means there is no wall to survive, just a consistent incline that rarely lets off. The 6.99% max tells you the hardest pitch is only a touch above the average, so the climb feels remarkably even underfoot. There are no crushing double-digit sections to blow your effort apart. Instead, expect a rhythm climb: settle into a cadence early, and the road will hold roughly that pitch until you crest at 830 m. The gap between the 208 m net gain and the 188 m of total ascent hints at minor undulation, so a short false-flat or gentle dip may briefly reset your legs before the grade resumes.

Pacing Notes

Because the gradient is so even, this climb rewards a disciplined, steady effort rather than repeated surges. Aim to hold a percentage of your FTP that you can sustain across the full 4.9 km without fading in the final third. On a climb this length, most riders can push comfortably above threshold in the closing stretch, since only 208 m of climbing separates you from the summit. If you are unsure of your threshold power, run the numbers through the FTP estimator before you ride, then set a target zone and trust it. With a 6.99% max, there is no section that demands a hard acceleration — resist the urge to spike your power on the steepest ramp and simply carry momentum through it.

Gearing

For a 4.24% average topping out at 6.99%, you do not need extreme gearing, but comfort matters on any sustained pitch. A compact chainring paired with a wide-range cassette is ideal. A 34×32 will cover most riders capably, letting you spin the steeper 6.99% ramp without grinding. If you prefer to keep cadence high, favour a longer effort, or ride this on tired legs, a 34×34 gives you a little more headroom to sit and stay smooth all the way to 830 m. Either setup lets you climb the full 4.9 km seated and in rhythm, which is exactly how a climb of this shape should be ridden.

Summary

Doroñu mendatea / Portillo del Reventón is a clean, even category-4 climb — short at 4.9 km, moderate at 4.24%, and never harsher than 6.99%. Pace it steadily, gear it sensibly, and enjoy the 208 m of lift to the top.

Length: 4.9 km
Average gradient: 4.24%
Max gradient: 6.99%
Start: 622 m
Summit: 830 m
Net gain: 208 m
Total ascent: 188 m
Category: 4