Colla della Giacobba

Overview

Colla della Giacobba is a category 3 climb that trades brute force for patience. Over 8.6 km it lifts you from 389 m to 731 m, a net gain of 342 m at an average gradient of 3.99%. On paper that average reads as gentle — a shade under 4% is the sort of grade you can hold in conversation — but the climb keeps a sharper card in reserve: a maximum pitch of 9.13%. The gap between that peak and the average tells you almost everything about how this road behaves. It is not a wall, and it is not a false flat. It is a rolling, uneven ascent where the effort ebbs and surges.

How the Gradient Unfolds

Do the arithmetic and the shape becomes clear. An average of 3.99% across 8.6 km means long stretches sit well below that figure to balance out the steeper sections. The 9.13% maximum is more than double the average, so the difficulty is front-loaded into a handful of ramps rather than spread evenly. Expect the road to relax to near-flat in places, then stiffen without much warning as it works around each rise in the terrain. The total ascent of 327 m sits just below the 342 m net gain, which confirms there is almost no descending mixed in — this is a climb that goes up, pauses, and goes up again, but rarely gives back altitude. Treat every easing as recovery, not as the summit arriving early.

Pacing Notes

Because the average is modest, the temptation is to attack from the base. Resist it. The steep 9.13% ramps are where riders who went out hard start paying interest. Anchor your effort to a percentage of your FTP rather than to how the road feels underfoot — a climb this uneven will lie to you. On the shallow sections, hold a controlled tempo and let the gradient do the pacing; save your matches for the pitches that touch 9%. If you do not know your threshold, spend five minutes with the FTP estimator first, then set a ceiling you can defend all the way to 731 m. A steady 8.6 km at a hair under 4% average rewards discipline far more than aggression.

Gearing

With a 9.13% maximum, you want enough range that the steep ramps never force you out of the saddle before you choose to be. A compact 34-tooth chainring is the sensible front. Pair it with a 34×32 for most riders — that combination covers the 3.99% average comfortably and gives a bail-out for the pitches. If you climb at a lower cadence, prefer a smaller frame, or simply want insurance on the 9.13% sections, step up to a 34×34. On a category 3 climb like this, the extra sprocket costs you nothing and buys spinning legs at the top.

Summary

Colla della Giacobba is a patient, uneven category 3 climb: long and forgiving on average, but with real teeth on its steepest ramp. Pace to your threshold, gear for the pitches, and let the numbers guide you.

Length: 8.6 km
Average gradient: 3.99%
Max gradient: 9.13%
Start: 389 m
Summit: 731 m
Net gain: 342 m
Total ascent: 327 m
Category: 3