Passo Colbricon

Overview

Passo Colbricon is a hors catégorie climb, the hardest grade a climb can carry, and its numbers explain why. Over 13.8 km the road rises from 847 m at the base to 2037 m at the summit, delivering 1190 m of net elevation gain at an average gradient of 8.62%. The recorded total ascent is 1178 m, a touch below the net figure, which tells you the profile trends upward almost without pause — there is little descending or flat to break the rhythm. This is a sustained, honest climb: no gentle valley run-in to warm the legs, just a long, uncompromising haul toward the high mountains.

How the Gradient Unfolds

An 8.62% average across 13.8 km is not a number you nibble at. Because the total ascent of 1178 m sits so close to the net gain of 1190 m, you can expect the slope to hold steady rather than swing between steep ramps and recovery flats. That consistency is a double-edged sword. On one hand, you can settle into a single rhythm and never have to react to sudden pitch changes. On the other, there is nowhere to soft-pedal and let the heart rate drop — the climb keeps asking the same hard question from the first metre to the last of the 1190 m you gain. Treat every kilometre as if it averages that full 8.62%, because on a climb this uniform, most of them will.

Pacing Notes

On a climb this long and steep, pacing is everything. The single biggest mistake is starting too hard on the lower slopes and paying for it across the back half of the 13.8 km. Anchor your effort to a percentage of your FTP rather than to feel — a sustained HC effort at 8.62% will chew through anyone riding above their sustainable ceiling. If you are not sure where that ceiling sits, run the numbers through the FTP estimator before you commit to a target. With 1190 m of vertical to absorb, aim to reach the halfway point feeling like you have more in reserve than you think you need. Steady beats heroic here every time.

Gearing

Do not undergear this one. With 13.8 km at 8.62% and a summit at 2037 m thinning the air, your cadence will sag long before the top if you run out of sprockets. A 34×32 is the sensible floor for strong climbers, but on a sustained HC gradient like this most riders will be grateful for a 34×34, which buys you the extra spin to keep the legs turning over instead of grinding. If your setup allows an even wider ratio, take it — carrying spare gears costs nothing and protects you across all 1190 m of climbing.

Summary

Passo Colbricon is a true hors catégorie test: long, steep and unrelentingly consistent. Pace it off your FTP, gear generously, and respect the 1190 m of climbing packed into 13.8 km.

Length: 13.8 km
Average gradient: 8.62%
Max gradient: n/a
Start: 847 m
Summit: 2037 m
Net gain: 1190 m
Total ascent: 1178 m
Category: HC