Colma di Sormano

Overview

Colma di Sormano is a category 1 climb that packs a serious punch into a compact 8.4 km. From a start elevation of 424 m to a summit at 1106 m, you gain 682 m of net elevation at an average gradient of 8.12%. That average alone tells you plenty: this is not a climb that eases you in and lets you settle. Eight percent held over more than eight kilometres is relentless territory, and with a maximum pitch of 12.37% waiting somewhere in the middle, there is no coasting your way to the top. It sits one rung below hors catégorie, and it earns that ranking honestly.

How the Gradient Unfolds

The gap between the 8.12% average and the 12.37% maximum is worth studying before you commit. A four-point spread means the climb is not uniform — the steepest ramps sit well above the mean, so for every stretch that touches 12.37% there must be gentler sections pulling the average back down to 8.12%. Expect the shape to alternate: sustained hard pitches that briefly kick toward that maximum, separated by shallower recovery grades that never truly flatten. The total ascent of 658 m against a net gain of 682 m confirms the road climbs almost continuously — there is very little descending or false-flat give-back over the 8.4 km. Read every steepening as a signal to hold back rather than attack, because the wall is more likely to return than to relent.

Pacing Notes

The single biggest mistake on a climb like this is starting too hard. At 8.12% average over 8.4 km, you will be on the gradient long enough that any early overreach compounds badly by the upper slopes. Anchor your effort to your FTP: on a sustained category 1 effort, most riders want to sit just below threshold and reserve headroom for the 12.37% ramps, where power spikes are unavoidable. If you do not know your threshold number, run the FTP estimator before you go so you have a target wattage rather than a guess. Meter your effort by the shallow sections — use them to bring your heart rate down, not to accelerate. The summit at 1106 m comes only after every metre of that 682 m gain is earned.

Gearing

Do not underdress your cassette here. With an 8.12% average and pitches to 12.37%, a compact chainring paired with a wide-range cassette is the sensible baseline. A 34×32 will get most fit riders up the steady sections, but on the 12.37% ramps late in the climb — when fatigue from 8.4 km of climbing has already accumulated — that bottom gear can feel marginal. If you climb at a lower cadence, carry extra weight, or simply want insurance, step up to a 34×34. The lower ratio lets you spin the steepest pitches rather than grinding them, which protects your legs across the full 682 m of ascent.

Summary

Colma di Sormano is a category 1 test of sustained climbing: 8.4 km that never lets the gradient drop far below its 8.12% average, with a 12.37% sting to keep you honest. Pace it below threshold, gear low, and respect the full 682 m from bottom to top.

Length: 8.4 km
Average gradient: 8.12%
Max gradient: 12.37%
Start: 424 m
Summit: 1106 m
Net gain: 682 m
Total ascent: 658 m
Category: 1