Colle di Vareno

Overview

Colle di Vareno is not a climb you ease into — it is a wall dressed up as a road. Over just 9.3 km it hauls you from 223 m at the base to 1379 m at the summit, a net gain of 1156 m. That works out to an average gradient of 12.39%, a figure that sounds like a typo until you are living inside it. For context, a steady 8% climb is already respected on any race route; Vareno beats that by more than four percentage points across its entire length.

At 9.3 km it is short by grand-tour standards, but the HC (hors catégorie) label is fully earned. Category exists on a scale from 4 (easiest) down through 3, 2, and 1 to HC (hardest), and Vareno sits at the very top of that ladder. This is a climb defined by sustained, almost unbroken steepness rather than length.

How the Gradient Unfolds

The number that reframes everything is the maximum gradient: 30.05%. That is roughly two and a half times the average, and it tells you the road does not hold a polite, even 12.39% the whole way — it surges. Expect stretches that sit near the average and then vicious ramps that spike toward that 30% ceiling before relenting.

There is a subtle tell in the elevation data. The net gain is 1156 m, but the total ascent is 1124 m — 32 m less. That small gap means the climb is not purely monotonic; there are brief flatter or slightly descending sections woven in. Those give you a heartbeat of recovery, but they also mean the climbing pitches around them must be even steeper than the 12.39% average to compensate.

Pacing Notes

On a climb this steep, pacing is survival. There is no soft-pedaling a 12.39% average — gravity sets a hard floor on your effort. Ride the flatter interruptions as genuine recovery, then brace for the ramps toward 30.05% where cadence collapses and power spikes whether you like it or not.

Anchor your effort to your FTP. On pitches this severe you will punch well above threshold in short bursts, so protect it on the rare shallow sections rather than the ramps, where you have no choice. If you are unsure of your number, run the FTP estimator before you commit to a pacing plan — guessing high on Vareno is how you blow up before halfway.

Gearing

Gear for the worst pitch, not the average. On a climb touching 30.05%, standard road gearing will have you weaving or walking. A compact 34-tooth chainring paired with a wide cassette is the minimum sane setup. A 34×32 is the entry point, but on the ramps toward that 30% maximum a 34×34 gives you the extra range to keep the pedals turning and your knees intact. If your frame accepts it, going even lower is defensible here — few climbs punish undergearing as harshly as this one.

Summary

Colle di Vareno is a concentrated dose of pure vertical: 9.3 km, 1156 m of net gain, and a gradient that never lets go. Come with low gears, a clear-eyed pacing plan, and respect for that 30.05% ceiling.

Length: 9.3 km
Average gradient: 12.39%
Max gradient: 30.05%
Start: 223 m
Summit: 1379 m
Net gain: 1156 m
Total ascent: 1124 m
Category: HC