Passo Zube

Overview

Passo Zube is a genuine hors catégorie giant. Over 43.3 km the road lifts you from a valley floor at 285 m all the way to a 2618 m summit — a net gain of 2333 m in a single sustained effort. The headline average of 5.38% sounds almost polite for an HC climb, but that figure hides the real story: with a total ascent of 2294 m packed into its length and a maximum pitch of 28.1%, Zube is a climb of dramatic contrasts rather than a steady drag. Expect a long day in the saddle where patience matters as much as power.

How the Gradient Unfolds

A 5.38% average across 43.3 km tells you this is not a wall-to-wall grind — there are flatter stretches and even brief respites where the road eases. But those milder sections are balanced by savage ramps, the steepest touching 28.1%. That gap between the average and the max is enormous, and it defines the character of the climb. You cannot simply lock into one rhythm and hold it for two-plus hours. Instead you ride the shape: settle in on the gentler grades, then brace for the pitches that spike far above threshold. The 2333 m of net elevation you gain is the true measure of the day, with total ascent of 2294 m confirming the climbing is almost entirely one-directional.

Pacing Notes

On a climb this long, discipline beats bravado. The single biggest mistake is burning matches early on the shallower grades, then blowing up when the 28.1% ramps arrive. Anchor your pacing to your FTP: on the sustained 5.38% sections, hold a controlled sub-threshold effort so you keep reserves for the steep pitches, where you'll unavoidably surge well above FTP for short bursts. If you don't know your number, run the FTP estimator before you go — pacing 43.3 km blind is a recipe for a walk. Fuel steadily from the bottom; at over 2000 m of climbing you'll be on the road long enough that nutrition, not fitness, often decides how the final kilometres feel. Thin air near the 2618 m summit will also blunt your top end, so bank your effort low.

Gearing

Gear for the 28.1% max, not the 5.38% average. On any climb that spikes this steep, running out of cogs turns a hard pitch into a dismount. A compact 34-tooth chainring paired with a wide cassette is the sensible baseline: 34×32 is the minimum I'd bring, and for most riders 34×34 is the smarter choice, giving you a lower bailout gear to spin the 28.1% ramps seated rather than grinding. If your legs will be deep into a 2294 m ascent before the steepest sections, that extra sprocket is cheap insurance. Riders comfortable with sub-1:1 gearing will thank themselves near the top.

Summary

Passo Zube rewards the patient and punishes the impulsive. Meter your effort across the long 5.38% flanks, save something for the 28.1% ramps, gear low, and treat the 2618 m summit as a distant goal rather than a sprint finish.

Length: 43.3 km
Average gradient: 5.38%
Max gradient: 28.1%
Start: 285 m
Summit: 2618 m
Net gain: 2333 m
Total ascent: 2294 m
Category: HC