Alto del Rayo

Overview

Alto del Rayo is a long-haul category 1 climb that rewards patience over power. Over 25.7 km it lifts you from a start elevation of 884 m to a summit at 1986 m, a net gain of 1102 m. The average gradient reads a modest 4.28%, but that number hides the real story: the total ascent of 1126 m tells you the road pitches, dips, and pitches again rather than dragging up at a single steady angle. This is a climb of sustained rhythm punctuated by moments that make you sit up and pay attention.

How the Gradient Unfolds

The gap between the 4.28% average and the 15.04% maximum is the key to reading this climb. On a uniform slope, average and max would sit close together. Here they are more than 10 percentage points apart, which means long stretches sit well below 4.28% while a handful of ramps bite hard into double digits. The difference between the 1126 m of total ascent and the 1102 m net gain also confirms there are short false flats or slight descents where the road gives a little back before demanding it again. Expect to roll through gentle, momentum-friendly sections, then brace for sharp kickers where the gradient briefly quadruples toward that 15.04% wall.

Pacing Notes

On a climb this long, the winning strategy is discipline. Anchor your effort to your FTP and resist the urge to chase the early ramps — 25.7 km is a lot of road to regret a hot start. Because the average is only 4.28%, you can often hold a steady, sustainable power on the shallower sections and simply absorb the steep pitches without blowing past threshold. Treat the 15.04% ramps as brief surges, not the baseline. If you are unsure what wattage to hold across 1102 m of climbing, run your numbers through the FTP estimator first and set a target you can defend all the way to 1986 m.

Gearing

For a 1102 m ascent that spikes to 15.04%, gear conservatively — spinning beats grinding on a climb you will be on for well over an hour. A compact 34-tooth chainring is the sensible front choice. Pair it with a 34×32 setup if you have strong legs and want a slightly firmer cadence on the shallower 4.28% stretches. But if you would rather protect your knees on the steepest ramps, the extra range of a 34×34 gives you a bailout gear that keeps your cadence alive when the road tilts into the mid-teens. When in doubt on a climb this long, choose the easier ratio.

Summary

Alto del Rayo is a test of pacing and patience: 25.7 km of climbing where a friendly 4.28% average masks ramps up to 15.04%. Manage your effort, gear low, and let the long stretches carry you to the 1986 m summit.

Length: 25.7 km
Average gradient: 4.28%
Max gradient: 15.04%
Start: 884 m
Summit: 1986 m
Net gain: 1102 m
Total ascent: 1126 m
Category: 1