Alto de Granadillo

Overview

Alto de Granadillo is short, but "short" is doing a lot of work here. Over just 2.4 km the road climbs from 1001 m to 1395 m, a net gain of 394 m packed into a distance most riders would cover in a few flat minutes. The average gradient of 16.75% tells you everything: this is a wall, not a mountain pass. There is no gentle valley run-in to settle into, no long tempo section to hide in. From the moment the pitch tilts up, you are riding at or near your limit, and you stay there until the summit. That relentlessness is exactly why it earns a Category 1 rating despite its modest length.

How the Gradient Unfolds

The defining number is the average: 16.75% sustained across the full 2.4 km. Climbs like this rarely hold a single grade, and the 23.87% maximum confirms it — there are ramps here that are nearly a quarter of vertical for every metre forward. When a climb averages this high and spikes this hard, the "easier" sections are still brutally steep, likely still in the low-to-mid teens. The gap between the 16.75% average and the 23.87% max is roughly seven points, so expect the road to surge and ease in pulses rather than settle. Total ascent comes in at 369 m against a net gain of 394 m, meaning the road climbs almost entirely upward with barely any respite or false descent to break the rhythm.

Pacing Notes

On a climb this steep, pacing is really about damage control. Your power will spike well above threshold on the 23.87% ramps whether you like it or not, so the goal is to keep those surges as brief as possible and recover on the "flatter" 16.75% sections — which are still hard. Riding much above your FTP for the full 2.4 km is not sustainable, so know your number before you start. If you are unsure where your threshold sits, run the numbers through the FTP estimator and use that to set a ceiling you try not to blow past early. Start conservatively: the temptation is to attack the base, but with 394 m of gain still above you, blowing up in the first third means grinding the rest at a crawl.

Gearing

Do not underestimate what 16.75% average with 23.87% maximum demands. This is a climb where a compact chainring is the starting point, not the safety net. A 34×32 is the bare minimum most strong riders will want, and even then you will be turning it over slowly on the steepest ramps. For most riders, and anyone not racing, a 34×34 is the smarter choice — that extra sprocket buys you cadence and spares your knees when the road hits its 23.87% max. If your bike can accommodate an even wider cassette, use it. On gradients this severe, spinning a low gear is faster and safer than mashing a bigger one to a standstill.

Summary

Alto de Granadillo is a pure test of steep-climbing strength: brief, savage, and unforgiving from bottom to top. Come with low gearing, a sensible pacing plan, and respect for the numbers.

Length: 2.4 km
Average gradient: 16.75%
Max gradient: 23.87%
Start: 1001 m
Summit: 1395 m
Net gain: 394 m
Total ascent: 369 m
Category: 1