Allarteko lepoa

Overview

Allarteko lepoa is a long, sustained category 1 climb that rewards patience over aggression. Across 18.3 km the road lifts you from 241 m at the base to 1147 m at the summit, a net gain of 906 m. The average gradient of 4.96% sounds gentle on paper, but a climb this long turns even a moderate slope into a serious test of endurance. The total ascent of 913 m confirms there is barely any respite along the way — almost every metre you gain, you keep.

How the Gradient Unfolds

The story here is length, not brutality. With a 4.96% average and a 906 m net gain over 18.3 km, this is a rhythm climb: pitch after pitch of steady false-flat-to-moderate grades that never let you fully recover but rarely bury you either. The sting comes from the 12.73% maximum, more than double the average. Ramps like that are where over-eager riders blow their pacing, so treat any sharp kick as a moment to shift down and protect your effort rather than a challenge to answer. Because total ascent (913 m) sits so close to net gain (906 m), there are almost no downhill breathers to reset your legs — you are climbing continuously for the better part of an hour or more.

Pacing Notes

On a climb of this duration, pacing is everything. Aim to settle just below your threshold and hold it. Your FTP is the number to anchor to: ride the bulk of the 18.3 km at a comfortable sub-threshold power, and only let yourself drift toward the red on the steepest sections near that 12.73% max. Going out hard in the opening kilometres is the classic mistake here — with 906 m still to climb, an early spike will cost you dearly in the final third. If you are unsure what wattage to target, run the numbers through the FTP estimator first and build your pacing plan around it. Fuel and drink early and often; at more than 18 km of continuous effort, this climb is as much a nutrition problem as a power problem.

Gearing

Given the 4.96% average and a 12.73% max, you want gearing that lets you spin rather than grind. A compact 34-tooth inner chainring paired with a wide cassette is the sensible baseline. A 34×32 will get most fit riders up the steady sections comfortably and give you enough range for the harder ramps. If you tend to climb at a lower cadence, carry extra weight, or simply want insurance for the steepest 12.73% pitches after 900-plus metres of climbing in the legs, step up to a 34×34. The extra teeth cost you almost nothing on the shallower stretches and buy you a real safety margin when the road bites.

Summary

Allarteko lepoa is a climber's endurance test: long, relentless, and steady, with just enough of a maximum ramp to punish poor pacing. Ride it smart, fuel it well, and gear it generously.

Length: 18.3 km
Average gradient: 4.96%
Max gradient: 12.73%
Start: 241 m
Summit: 1147 m
Net gain: 906 m
Total ascent: 913 m
Category: 1