Passo del Dil

Overview

Passo del Dil is a hors catégorie ascent that earns its top billing the honest way — through relentless length paired with a savage average gradient. Over 20.6 km the road drags you from a start elevation of 62 m up to a summit at 1715 m, a net elevation gain of 1653 m. The total ascent comes to 1733 m, meaning the climb concedes only a little respite along the way before clawing it all back. At 8.04% average across that full distance, there is no easing-in phase to hide behind. This is a climb that asks a single, sustained question for the better part of an hour, and the answer is written entirely in your legs.

How the Gradient Unfolds

The defining number here is consistency. An 8.04% average holding for 20.6 km is not a spiky profile with a few brutal ramps and long recoveries — it is a wall tilted just past the threshold where riding becomes suffering. Because the net gain of 1653 m sits close to the total ascent of 1733 m, the descents and flat sections that would normally let you soft-pedal barely exist. The difference between the two figures is only 80 m, so for practical purposes you are climbing the entire time. Expect the grade to hover around its average for long stretches, with the steeper pitches offset by sections that are merely hard rather than desperate. Treat every kilometre as if it were the average, and you will rarely be surprised.

Pacing Notes

On a climb this long, pacing is the whole game. The smart approach is to ride the entire 20.6 km just under your sustainable ceiling — your FTP — rather than chasing the early gradient and blowing apart before the halfway mark. With 1653 m to gain, a single overcooked effort in the first third can cost you far more time than it ever bought. If you are unsure where your ceiling sits, run your recent numbers through the FTP estimator before you commit to a target. Settle into a rhythm you could hold in conversation-free discomfort, and let the summit at 1715 m come to you. The riders who crest fastest are almost never the ones who attacked the lower slopes.

Gearing

Do not under-gear this one. A 20.6 km climb at 8.04% will grind down anything too tall long before the top. For most riders a compact 34-tooth chainring paired with a wide cassette is the sensible baseline: a 34×32 gives you enough range to keep a workable cadence on the average slopes, while a 34×34 buys precious extra spin for the steeper pitches and the accumulated fatigue of the final kilometres. Given the sheer 1653 m of gain, err toward the easier 34×34 if you have any doubt — spinning a low gear costs nothing and preserves your legs for the summit.

Summary

Passo del Dil is a pure hors catégorie effort: long, steep, and unforgiving from bottom to top. Pace it patiently, gear it generously, and respect the full 20.6 km, and this HC giant becomes a rewarding challenge rather than a day-ender.

Length: 20.6 km
Average gradient: 8.04%
Max gradient: n/a
Start: 62 m
Summit: 1715 m
Net gain: 1653 m
Total ascent: 1733 m
Category: HC