Colle di Bellino

Overview

Colle di Bellino is a full-blown hors catégorie (HC) climb — the hardest rating there is, sitting above categories 1 through 4. It runs 24.6 km from a start elevation of 965 m to a summit at 2792 m, and that spread alone tells you what you're in for: a net elevation gain of 1827 m and a total ascent of 1786 m packed into a single, uninterrupted effort.

The headline average gradient is 7.43%, which is brutally steep to hold for the better part of an hour or more. But averages flatten the truth. This climb also throws a maximum pitch of 37.87% at you — a near-vertical ramp that no amount of fitness lets you spin through comfortably. Bellino is a climb of endurance first and raw torque second.

How the Gradient Unfolds

Think of Bellino in terms of its shape rather than a smooth ramp. Over 24.6 km, a 7.43% average means the road almost never relents — there's no long flat recovery baked into the number. Because the total ascent (1786 m) sits just below the net gain (1827 m), you can infer there's essentially no meaningful descending along the way. It climbs, and keeps climbing.

The 37.87% maximum gradient is the defining spike. A pitch that severe is roughly five times steeper than the average, so somewhere on this mountain the road rears up far beyond anything you can pace evenly. Everything around that ramp will feel like a grind by comparison. Expect the difficulty to compound as you gain altitude toward 2792 m, where thinner air quietly steals watts you'd normally have.

Pacing Notes

At 24.6 km and 7.43%, Bellino is long enough that pacing decides your day. Anchor your effort to your FTP rather than to how the first kilometres feel — the opening ramps always feel easy, and riders routinely overcook them. If you don't know your number, run it through the FTP estimator before you plan this climb.

A sustainable target for an ascent this long is comfortably below FTP, leaving headroom for the 37.87% wall, which will spike your power far into the red no matter how disciplined you've been. Ride the steady sections at a controlled tempo, then simply survive the steepest pitch and settle back down. With 1827 m to gain, patience beats bravado every time.

Gearing

Gear for the wall, not the average. A 7.43% mean over 24.6 km already demands generous ratios, and the 37.87% maximum makes an easy bailout gear non-negotiable. A compact 34-tooth chainring paired with a wide cassette is the sensible starting point.

For strong climbers, 34×32 is the minimum I'd bring — and even then, expect to be grinding on the steepest ramp. Most riders will be far happier on 34×34, which buys precious cadence when the road tips toward 37.87% and altitude near 2792 m saps your legs. If your bike accepts an even larger sprocket, take it. On a climb gaining 1827 m, spare gears cost nothing and save everything.

Summary

Colle di Bellino is a genuine HC test: long, relentless, and topped off with a savage wall. Come with endurance, a disciplined pacing plan, and gearing built for the worst pitch, not the average one.

Length: 24.6 km
Average gradient: 7.43%
Max gradient: 37.87%
Start: 965 m
Summit: 2792 m
Net gain: 1827 m
Total ascent: 1786 m
Category: HC