Túnel del Cadí

Overview

Túnel del Cadí is a hors catégorie (HC) climb in Spain, and the numbers make the case on their own. Over 9.4 km it averages a punishing 10.93%, lifting you from a start elevation of 810 m to a summit at 1841 m. That is a net gain of 1031 m, with 1008 m of total ascent packed into a single sustained effort. Add a max gradient of 34.58% and you have one of the hardest categories of climb a rider can face — a wall that rarely lets up and occasionally kicks into territory most cyclists never see.

How the Gradient Unfolds

Understanding the shape matters more than the average. A 10.93% mean across 9.4 km tells you there is almost nowhere to recover: this is not a climb with a gentle apron and a savage finish, it is relentless throughout. The gap between the 10.93% average and the 34.58% max is the whole story — spikes of that severity mean short ramps that briefly more than triple the effort of the average slope. With net gain (1031 m) sitting close to total ascent (1008 m), there is very little downhill or flat mixed in; you are climbing essentially the entire 9.4 km. Expect to settle into a grinding rhythm early and hold it, bracing for the steepest pitches rather than hoping for flats that never arrive.

Pacing Notes

On a climb this steep and this long, pacing is survival. Anchor your effort to your FTP and resist the urge to attack the lower slopes — with 9.4 km at 10.93% ahead, an early overshoot compounds badly. On the ramps toward that 34.58% max you will unavoidably spike above threshold; the key is keeping those surges as brief as possible and returning to a sustainable power the moment the gradient eases. If you do not know your threshold, run the numbers through the FTP estimator before you ride so you have a target rather than a guess. Given 1031 m of climbing, treat the whole ascent as a threshold time trial with unwanted anaerobic interruptions, and fuel accordingly.

Gearing

Gear low, then lower. For an HC climb averaging 10.93% with pitches to 34.58%, a compact setup is the minimum. A 34×32 will get many strong climbers to the top, but on the steepest ramps it can force you into a grinding cadence that torches your legs. If you have any doubt about your climbing power, go to a 34×34 — the extra range keeps your cadence spinning where a 34×32 would bog down. Over 9.4 km and 1031 m of gain, protecting your cadence is protecting your ride.

Summary

Túnel del Cadí is a true HC test: short by grand-tour standards but savage in pitch, with a sustained 10.93% average and a 34.58% max that demands respect and low gearing. Pace it to your threshold, gear generously, and treat every ramp as its own problem.

Length: 9.4 km
Average gradient: 10.93%
Max gradient: 34.58%
Start: 810 m
Summit: 1841 m
Net gain: 1031 m
Total ascent: 1008 m
Category: HC