Passo Bonello

Overview

Passo Bonello is a category-1 climb that covers 12.8 km and averages 7.16%, lifting you from a valley floor at 198 m to a summit at 1112 m. That is 914 m of net elevation gain, with 898 m of total ascent — the two figures sitting close together, which tells you this is a climb that goes up and stays up rather than teasing you with descents. Category 1 sits one rung below hors catégorie, so expect a genuine test: not the hardest label on the scale, but demanding enough that pacing and gearing matter from the first pedal stroke.

How the Gradient Unfolds

A 7.16% average across 12.8 km is a relentless number. There is very little rolling terrain here — with only 898 m of total ascent against 914 m of net gain, the road climbs almost the entire way with negligible respite. The defining feature is the max gradient of 12.96%, nearly double the average. Sections that steep are what break a rhythm, so the climb is best understood as a long, sustained grind punctuated by ramps that spike well above the mean. Treat the average as your baseline effort and the 12.96% pitches as the moments where you protect your legs rather than chase a personal best.

Pacing Notes

On a sustained 7.16% climb of this length, the smartest strategy is to hold a steady, sub-threshold effort and let the mountain come to you. Anchor your pace to your FTP: riding the flatter-averaging kilometres at a controlled percentage of it leaves headroom for the 12.96% ramps, where power naturally surges as cadence drops. Going into the red early on a 12.8 km climb almost always costs more time than it saves. If you are unsure of your number, run it through the FTP estimator before you commit to a target. With 914 m of vertical to absorb, consistency beats heroics every time.

Gearing

For a 12.8 km climb averaging 7.16% and spiking to 12.96%, gear low and keep something in reserve. A compact 34-tooth chainring paired with a wide cassette is the sensible foundation. A 34×32 will get most trained riders up at a manageable cadence on the sustained pitches, but the near-13% ramps are where you will be grateful for one more sprocket — a 34×34 gives you that extra margin to spin rather than grind when the road kicks. If your legs or your loaded bike suggest you will be struggling, choose the 34×34: over 914 m of climbing, protecting your cadence pays dividends the higher you go.

Summary

Passo Bonello is a sustained category-1 effort: 12.8 km of near-constant climbing at 7.16%, with ramps to 12.96% that reward disciplined pacing and low gearing. Ride within yourself, gear for the steep sections, and let the 914 m of gain unfold at a rhythm you can hold to the summit.

Length: 12.8 km
Average gradient: 7.16%
Max gradient: 12.96%
Start: 198 m
Summit: 1112 m
Net gain: 914 m
Total ascent: 898 m
Category: 1