Colle d'Oggia

Overview

Colle d'Oggia is a long, sustained category-1 ascent that rewards patience over aggression. Over 16.9 km the road climbs from 126 m at the base to 1150 m at the summit, a net gain of 1024 m. That length alone puts it firmly among the day's big objectives: at an average gradient of 6.04%, there is nowhere to properly recover, but nothing so brutal that a well-paced rider cannot settle into a rhythm and hold it. The total ascent of 1010 m confirms this is a near-continuous climb rather than a rolling profile disguised as one.

How the Gradient Unfolds

The headline number, 6.04%, tells only part of the story. A climb this long almost never delivers its average evenly, and the max gradient of 12.32% is roughly double that mean — a clear sign of steeper ramps punctuating the softer stretches. Expect the road to breathe: sections a little below 6% where you can carry speed, then pitches that bite well into double digits and force you out of the saddle or down a gear. The gap between the 1024 m net gain and the 1010 m total ascent is tiny, meaning there is virtually no descending or false flat to break the effort. Once you start climbing, you keep climbing to 1150 m.

Pacing Notes

On a 16.9 km climb, discipline in the opening kilometres decides everything. Anchor your effort to a percentage of your FTP rather than to how you feel at the base, where fresh legs tempt you into a pace you cannot sustain for over an hour of climbing. A sensible target for a sustained category-1 effort is to sit just under threshold on the steadier 6% sections and allow the 12.32% ramps to push you briefly above it, absorbing the surges without panicking. If you are unsure what wattage that corresponds to, run your numbers through the FTP estimator before you ride, then hold that ceiling honestly through the middle third, where fatigue quietly accumulates against the 1024 m of gain still stacking up.

Gearing

Given the length and the 12.32% maximum, gearing generously is the smart move here. A compact 34-tooth inner chainring paired with a wide-range cassette will keep your cadence alive when the road ramps up. A 34×32 is the practical minimum for most fit riders and will get you over the steepest pitches without grinding to a crawl — but on a climb this sustained, where the 1010 m total ascent taxes the legs long before the summit, a 34×34 buys valuable insurance. That extra sprocket lets you spin rather than muscle the 12.32% sections, preserving your legs across the full 16.9 km. If in doubt, choose the easier gear.

Summary

Colle d'Oggia is a genuine category-1 test: long, steady, and unrelenting from 126 m to 1150 m. Pace it conservatively, gear it generously, and respect that the average hides sharper teeth. Get those two decisions right and the 16.9 km reward you with a satisfying, rhythmic climb rather than a survival exercise.

Length: 16.9 km
Average gradient: 6.04%
Max gradient: 12.32%
Start: 126 m
Summit: 1150 m
Net gain: 1024 m
Total ascent: 1010 m
Category: 1