Colle Lazoney

Overview

Colle Lazoney is a long, serious Category 1 ascent that rewards patience over aggression. At 21.9 km, it is a climb you settle into rather than attack. The road starts at 287 m and finishes at 1552 m, a net elevation gain of 1265 m across the full distance. The average gradient of 5.78% sounds manageable on paper, and for long stretches it is — but that number hides real teeth. Somewhere along the way the road ramps to 27.67%, a gradient steep enough to bring even strong riders to a near standstill. Understanding where the effort lives is the difference between a controlled ride and a blow-up.

How the Gradient Unfolds

A 21.9 km climb averaging 5.78% is not evenly paved. The total ascent of 1245 m is slightly less than the 1265 m net gain would suggest, which tells you the profile is essentially relentless uphill with almost no false-flat relief or descending recovery — the road just keeps rising. The headline hazard is the 27.67% maximum pitch. A ramp roughly five times steeper than the average cannot be sustained, so expect it to be a short, brutal wall bracketed by more moderate slopes. Mentally, break the climb into thirds of about 7.3 km each and treat the steep sections as isolated efforts rather than the norm.

Pacing Notes

Over 21.9 km, discipline wins. Anchor your effort to a percentage of your FTP and refuse to chase it above threshold early, because there is a lot of mountain left after the first ramps. A sustainable target for a climb this long is comfortably below threshold, with brief surges only where the 27.67% wall forces them. If you do not know your threshold power, run the numbers through the FTP estimator before you ride so your pacing bands are honest. On a 1265 m ascent, going one gear too hard in the first third is the most common way to lose ten minutes in the last third.

Gearing

Gear for the wall, not the average. The 5.78% mean is spinnable on almost anything, but the 27.67% maximum gradient demands a genuine bailout ratio. A compact 34-tooth chainring paired with a 34×32 low is the sensible floor for most fit riders here, and if you climb seated and value cadence, step up to 34×34 for extra margin on the steepest ramp. Given the 21.9 km length, protecting your legs early with an easier gear pays dividends late — spinning a 34×34 slowly beats grinding a 34×32 into the red.

Summary

Colle Lazoney is a full 21.9 km of climbing that earns its Category 1 rating through sheer length and one savage 27.67% pitch. Pace it below threshold, gear low for the wall, and respect the 1265 m of vertical between the 287 m start and the 1552 m summit.

Length: 21.9 km
Average gradient: 5.78%
Max gradient: 27.67%
Start: 287 m
Summit: 1552 m
Net gain: 1265 m
Total ascent: 1245 m
Category: 1