Colle del Quazzo

Overview

Colle del Quazzo is a long, category-1 effort that trades brutal steepness for sheer duration. Over 23.4 km it lifts you from a near-sea-level start of 11 m to a summit at 1137 m, a net gain of 1126 m. The average gradient of 4.81% sounds gentle on paper, but 23.4 km of continuous uphill is a very different animal from a short, sharp wall. This is a climb you settle into rather than attack, where rhythm and patience matter far more than raw power.

How the Gradient Unfolds

The headline number is that 4.81% average, but averages hide the story. The total ascent of 1150 m sits slightly above the 1126 m net gain, meaning there are small dips or false flats where the road briefly gives back elevation before clawing it back again. That 24 m difference tells you the profile is not perfectly smooth. The real sting is the 16.3% maximum gradient — a ramp more than three times the average that will spike your effort well above anything sustainable for 23.4 km. Expect long stretches near the 4.81% mean punctuated by steeper pitches that force you out of your comfortable cadence.

Pacing Notes

On a climb this long, discipline is everything. Anchor your effort to your FTP and hold steady rather than chasing surges. A climb of 23.4 km can easily take an hour or more, so aim to ride the shallower sections at or just below threshold and reserve headroom for the 16.3% ramps, where power will naturally jump. If you do not have a current threshold figure, work one out with the FTP estimator before you commit to a pacing plan — going out too hard in the first few kilometres of a 23.4 km ascent is the classic way to blow up long before the 1137 m summit. Keep fuelling early and often; the length here punishes anyone who under-eats.

Gearing

Given the 23.4 km length and pitches up to 16.3%, gear for comfort, not ego. A compact 34-tooth inner chainring paired with a wide-range cassette is the sensible baseline. A 34×32 will carry most riders through the steeper sections while keeping cadence respectable, but if you tire on long climbs or ride at a lower power-to-weight, step up to a 34×34 for extra breathing room on the 16.3% ramps. The lower gear costs you almost nothing on the shallow 4.81% stretches and buys real insurance deep into the climb when your legs are 1126 m of gain into the day.

Summary

Colle del Quazzo rewards the patient. It is not the steepness that defines it but the relentless 23.4 km of climbing from 11 m to 1137 m. Pace it to your threshold, gear generously, and let the 4.81% average work for you rather than against you.

Length: 23.4 km
Average gradient: 4.81%
Max gradient: 16.3%
Start: 11 m
Summit: 1137 m
Net gain: 1126 m
Total ascent: 1150 m
Category: 1