Passo del Grostè

Overview

Passo del Grostè is a hors catégorie monster: 29.8 km of continuous climbing at a 7.32% average gradient. It starts at 261 m and tops out at 2443 m, delivering 2182 m of net elevation gain and 2172 m of total ascent. That near-identical pair of numbers tells you something important — this is an almost relentlessly uphill road, with barely any downhill or flat to break the rhythm. Over nearly thirty kilometres, the mountain keeps pointing skyward, and with a max gradient of 23.52% it saves a genuine wall or two for anyone still feeling comfortable.

How the Gradient Unfolds

The headline 7.32% average is honest but deceptive. Averages smooth over the spikes, and on a climb this long a steady 7.32% would already be a serious day out. What makes the Grostè harder than its average suggests is the spread between that mean and the 23.52% maximum — a gap of more than sixteen points. Ramps that steep don't sit alone; they punctuate the middle and upper reaches, forcing repeated surges out of a sustainable tempo. Because total ascent (2172 m) sits just below net gain (2182 m), there is essentially nowhere to recover with your legs turning freely. Every metre climbed stays climbed. Plan for the gradient to swing well above and below 7.32% rather than holding it, and treat the steepest pitches as the crux late in a very long effort.

Pacing Notes

On a climb of 29.8 km you cannot bluff your way up — this is an exercise in metering effort against a hard ceiling. Anchor your pacing to your FTP and aim to spend most of the climb comfortably below threshold, banking energy for the 23.52% ramps rather than burning matches on the early kilometres. If you don't know your threshold, run the numbers through the FTP estimator before you commit to a target. A useful rule at 7.32% average over this distance: if the first third feels hard, the final third will break you. Ride the steep sections at whatever cadence keeps you moving without lunging over the pedals, and let the average gradient — not your ego — set the pace.

Gearing

Gearing is not optional insurance on the Grostè, it is the difference between finishing and walking. With 2182 m of gain and pitches touching 23.52%, you want a compact up front and a wide cassette behind. A 34×32 is the sensible floor for strong climbers, but on the steepest ramps late in a 29.8 km effort a 34×34 will keep your cadence alive and your knees intact. If your setup allows even lower, take it — spinning up a 23.52% wall beats grinding it. Err toward easier gearing than you think you need; the length of the climb multiplies every mistake.

Summary

Passo del Grostè is a true HC test: long, unrelenting, and steep where it counts. Respect the 29.8 km, gear low for the 23.52% ramps, and pace off your threshold from the very first kilometre.

Length: 29.8 km
Average gradient: 7.32%
Max gradient: 23.52%
Start: 261 m
Summit: 2443 m
Net gain: 2182 m
Total ascent: 2172 m
Category: HC