Tremalzo Pass

Overview

Tremalzo Pass is a genuine hors catégorie ascent, and the numbers make no apology for it. Over 19.4 km the road climbs from a low start of 62 m all the way to a summit of 1695 m, delivering 1633 m of net elevation gain. With a few dips and false flats folded in, the total ascent tops out at 1710 m. What sets this climb apart is not a single savage ramp but the sheer sustained load: an average gradient of 8.4% held across almost twenty kilometres. There is no meaningful recovery built into that average — it is nearly two thousand metres of vertical work stacked into a single, unbroken effort.

How the Gradient Unfolds

An 8.4% average over 19.4 km is the defining shape here. To gain 1633 m net across that distance, the road has to sit near its average for long stretches rather than trading brutal ramps for flat rest. The 1710 m of total ascent versus 1633 m net tells you there are small descents or flatter sections mixed in — roughly 77 m of extra climbing that gets given back before the summit. Practically, that means a handful of kilometres will bite above the average to compensate for those softer patches. Treat the whole climb as one long, high-tempo block rather than a series of discrete efforts, because the gradient rarely lets you sit up and coast.

Pacing Notes

On a climb this long, pacing is everything. Riding at or just below your FTP is the only sustainable strategy — go over it early and the remaining kilometres of 8.4% will unravel you well before 1695 m. Aim to settle into a steady rhythm from the base at 62 m and hold it, resisting the urge to chase the steeper pitches. If you are unsure where your ceiling sits, run the numbers through the FTP estimator before you commit, then ride the climb at a percentage of that figure you know you can hold for the full 19.4 km. The riders who reach the top strongest are almost always the ones who paced the first half most conservatively.

Gearing

Bring low gears. For a 1633 m net gain sustained at 8.4%, a compact setup is the sensible baseline: a 34-tooth inner ring paired with a wide cassette. A 34×32 will get most trained riders up Tremalzo Pass, but on a climb this long and this steep the smart insurance is a 34×34, which gives you a lower floor to spin on the harder pitches without grinding. The longer you can keep your cadence up over 19.4 km, the fresher your legs will be near the summit. If your legs or your target time leave any doubt, err toward the 34×34 — the extra range costs nothing when the road eases and buys you real margin when it does not.

Summary

Tremalzo Pass is a long, sustained HC climb that rewards patience and punishes bravado: 19.4 km at 8.4%, from 62 m to 1695 m, with 1633 m of net gain. Pace it off your FTP, gear it low, and let the rhythm carry you.

Length: 19.4 km
Average gradient: 8.4%
Max gradient: n/a
Start: 62 m
Summit: 1695 m
Net gain: 1633 m
Total ascent: 1710 m
Category: HC