Buco di Grigna

Overview

Buco di Grigna is an HC-category climb in Italy, running 23.8 km from a base at 195 m to a summit at 2,095 m. Over that distance it delivers a net elevation gain of 1,900 m at an average gradient of 7.97%. Those are big, serious numbers: an HC rating is reserved for climbs that sit beyond ordinary first-category difficulty, and both the length and the vertical here justify it. This is a full-day objective, not a warm-up.

The number that reshapes the effort is total ascent: 2,458 m against a net gain of 1,900 m. That 558 m gap means the road does not climb cleanly. You give back roughly 558 m of descending along the way and have to re-earn it, so the metres your legs actually push through are close to 2,458, not 1,900. Treat this as a longer, lumpier day than the net figure suggests.

How the Gradient Unfolds

An average of 7.97% is a blend, not a constant. The undulation implied by the 558 m of extra ascent tells you the profile swings above and below that mean repeatedly. Expect stretches noticeably steeper than 8% offset by dips and false flats that pull the average down. Do not read the average as your working gradient on the hard pitches.

• Flatter or descending recovery sections where you give back part of the 558 m of surplus ascent
• Repeated short climbs that stack up to the 2,458 m total rather than one smooth ramp
• Steep pitches that sit well above the 7.97% average and set your gearing needs

Pacing Notes

On an undulating climb like this, chase even effort, not even speed. Holding a constant pace forces you over your limit on the steep pitches and wastes energy coasting the dips. Anchor your ride to a sustainable power output you can hold for the full 23.8 km, let speed rise on the flatter sections, and accept that it will drop on the ramps.

Before you go, pin down your ceiling with the FTP estimator. With 2,458 m of real ascent in your legs, starting even slightly too hard compounds badly over the back half.

Gearing

Gear for the steep pitches, not the average. On an HC climb of this length with sharp ramps, run a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you a low enough bailout to spin the worst gradients without grinding. The goal is to protect your cadence when the road kicks up so you are not forced out of the saddle repeatedly over 23.8 km.

Check your actual setup before the ride. Confirm the cassette and chainset are what you think they are, and that the derailleur handles the largest sprocket cleanly.

Summary

• Length: 23.8 km
• Average gradient: 7.97%
• Net elevation gain: 1,900 m
• Total ascent: 2,458 m
• Category: HC

Buco di Grigna is a genuine HC test: long, high, and lumpier than its net gain admits. Respect the 2,458 m of real climbing, pace to sustainable effort, and bring low gears.