Bocchetta di Desio

Overview

Bocchetta di Desio is a hors catégorie climb — the hardest rating on the scale, sitting above categories 1, 2, 3 and 4 — and its numbers explain why. Over 14.6 km the road lifts you from 198 m at the base to a summit of 1336 m, a net elevation gain of 1138 m. The average gradient is a relentless 7.82%, and unlike many climbs that pad their average with easy stretches, this one has genuine teeth: the steepest pitch bites at 27.95%. With a total ascent of 1117 m recorded along the way, there is almost no respite built into the profile. This is a climb you commit to at the bottom and manage all the way to the top.

How the Gradient Unfolds

The story here is the gap between the average and the maximum. A 7.82% mean over 14.6 km would already be a serious effort, but the 27.95% peak means the climb is not evenly loaded — steep ramps punctuate the ascent and force repeated changes in effort and cadence. With 1138 m of net gain but 1117 m of total ascent, the road climbs almost continuously; there is very little false-flat or descending to recover on. Expect the gradient to swing well above the average through the steepest sections, then settle back toward it, never truly easing. Reading the profile in blocks rather than as a single steady grind is the key to surviving the sharpest kicks near 27.95%.

Pacing Notes

On a climb this long and this steep, pacing beats bravado. Anchor your effort to your FTP and hold something in reserve for the ramps — the 27.95% pitches will spike your power far above threshold no matter how disciplined you are, so you want headroom when they arrive. Aim to ride the 7.82% average stretches at a controlled, sustainable intensity, then accept short surges over threshold on the steepest sections rather than fighting to hold a fixed number. If you are unsure of your threshold, run the numbers first with the FTP estimator so your targets for all 14.6 km are grounded in real data rather than guesswork.

Gearing

Gear for the maximum, not the average. A 7.82% mean is hard enough, but the 27.95% ramps are where compact-only setups fall apart. A 34×32 is the sensible minimum for most riders tackling 1138 m of climbing, and if you want to protect your knees and keep spinning through the steepest pitches, step up to a 34×34. Given the sustained nature of the 14.6 km — 1117 m of total ascent with barely a break — the lower ratio is rarely wasted. Better to carry a gear you never fully need than to grind to a standstill at 27.95%.

Summary

Bocchetta di Desio is a true HC test: long, steep, and unforgiving from the 198 m base to the 1336 m summit. Respect the 27.95% ramps, pace off your threshold across the 7.82% average, and gear low. Do that, and the 1138 m of climbing becomes a challenge you finish rather than one that finishes you.

Length: 14.6 km
Average gradient: 7.82%
Max gradient: 27.95%
Start: 198 m
Summit: 1336 m
Net gain: 1138 m
Total ascent: 1117 m
Category: HC