Puerto del León

Overview

Puerto del León is a long, patient category 1 ascent that stretches 20.9 km from a near-sea-level start of just 1 m all the way to a 931 m summit. That is a net gain of 930 m, with 937 m of total ascent once the small dips along the way are counted. At 20.9 km this is a climb measured in tens of minutes rather than a handful, and its 4.44% average gradient tells you this is a rhythm climb, not a wall. The category 1 label — one step below the fearsome HC — is earned through sheer length and sustained effort rather than brutal steepness, though a 12.58% maximum ramp proves it can still bite.

How the Gradient Unfolds

With a 4.44% average spread across 20.9 km, most of Puerto del León sits at a gradient you can hold in the saddle and breathe through. But an average of 4.44% alongside a 12.58% maximum reveals an uneven road: there are stretches noticeably gentler than the mean, offset by pitches that spike almost three times steeper. Expect the climb to breathe — shallow drags where you can settle, punctuated by short, sharper kicks toward that 12.58% high point. The gap between the 930 m net gain and the 937 m of total ascent confirms the profile is not perfectly monotonic; a few brief easings let the road claw back a handful of metres before resuming the march upward.

Pacing Notes

On a climb this long, restraint early is everything. The temptation on the gentler lower slopes is to push hard, but 20.9 km will punish anyone who overcooks the opening kilometres. Anchor your effort to your FTP: on a sustained category 1 ascent, riding at or just below threshold is a defensible target for a strong effort, while dropping comfortably under it is the smart play if you want to reach the 931 m summit with something left. If you are unsure where your threshold sits, run the numbers through the FTP estimator before you plan your pacing. When the road tilts toward 12.58%, let your effort rise briefly rather than fighting to hold a fixed pace — then settle back to rhythm once the ramp relents.

Gearing

The 4.44% average is manageable on almost any setup, but 20.9 km of continuous climbing rewards spinning over grinding. A compact crankset paired with a wide cassette is the sensible choice here. A 34×32 gives most riders enough range to keep a steady cadence through the bulk of the climb, and it will carry you over the steeper pitches without forcing you out of the saddle for long. If you know you fade on long ascents, or you are carrying fatigue, step up to a 34×34 for extra insurance on the 12.58% sections — the lower gear lets you protect your legs across the full 930 m of gain rather than burning matches early.

Summary

Puerto del León is a true endurance climb: nearly 21 kilometres of steady elevation from sea level to a high mountain summit, with just enough steepness to keep it honest. Pace it patiently, gear it generously, and let the 4.44% average carry you upward.

Length: 20.9 km
Average gradient: 4.44%
Max gradient: 12.58%
Start: 1 m
Summit: 931 m
Net gain: 930 m
Total ascent: 937 m
Category: 1