Bocchetta di Trona

Overview

Bocchetta di Trona is a hors catégorie ascent that demands respect from the first pedal stroke. Over 22.3 km the road lifts you from a 240 m start to a 2097 m summit, a net gain of 1857 m. The average gradient reads 8.33%, but that single figure hides the real story: with a maximum pitch of 31.1%, this is a climb of savage ramps rather than a steady drag. The total ascent of 1808 m confirms the road rarely relents — there is very little false-flat or descent to break the effort.

At more than 22 km in length and averaging over 8%, this sits among the most serious sustained efforts you can attempt. It is long enough to test endurance and steep enough to test raw power, and its HC rating is fully earned.

How the Gradient Unfolds

The defining number here is the gap between the 8.33% average and the 31.1% maximum. That spread of nearly 23 percentage points tells you the climb is built in surges. Expect long stretches near or above the average punctuated by wall-like ramps that briefly touch gradients most riders only ever see on the steepest urban lanes.

Because total ascent (1808 m) is slightly less than net gain (1857 m) is not the case here — in fact net gain exceeds total ascent listed, meaning the road climbs almost continuously with negligible respite. Every one of those 22.3 km is contributing upward. Plan for the effort to be relentless: there are no long recovery sections to bank on, so the steep pitches arrive on already-fatigued legs.

Pacing Notes

On a climb this long, discipline early is everything. Anchor your effort to your FTP and resist the temptation to chase the opening ramps. Aim to sit comfortably below threshold on the sustained sections so you have headroom for the 31.1% spikes, where power will surge involuntarily.

If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target. A climb of 22.3 km at 8.33% will punish an over-ambitious start ruthlessly — the final kilometres toward the 2097 m summit are where poor pacing is exposed. Break the ascent into segments, ride to power on the steady parts, and treat each steep ramp as a short, controlled over-threshold effort rather than a sprint.

Gearing

Do not under-gear this one. With ramps reaching 31.1% and an average of 8.33% sustained across 22.3 km, a compact chainring paired with a wide-range cassette is the minimum sensible setup. A 34×32 will get most fit riders up the steady sections, but on the steepest pitches it can force you into a grinding, muscle-shredding cadence.

If you have any doubt about your climbing legs or your loaded weight, fit a 34×34. The extra sprocket keeps your cadence alive on the 31.1% walls and protects your knees over a 1857 m ascent. On a climb this severe, spare gears are never wasted.

Summary

Bocchetta di Trona is a genuine hors catégorie test: long, steep, and unforgiving from 240 m to 2097 m. Pace it with humility, gear it generously, and the summit is yours.

Length: 22.3 km
Average gradient: 8.33%
Max gradient: 31.1%
Start: 240 m
Summit: 2097 m
Net gain: 1857 m
Total ascent: 1808 m
Category: HC