Passo delle Lame

Overview

The Passo delle Lame is one of those climbs that leaves nothing to interpretation. Over 12.8 km it hauls you from a start elevation of 122 m up to a summit at 1383 m, a net gain of 1261 m. That works out to an average gradient of 9.87% — a number that stays punishing for the full distance rather than being propped up by one savage wall. Rated hors catégorie (HC), the hardest classification above categories 1 through 4, it sits firmly in the tier of ascents that reward respect and punish overconfidence. With a maximum gradient of 27.31%, this is a climb where the road genuinely rears up in front of you.

How the Gradient Unfolds

Sustained is the word that matters here. A 9.87% average across 12.8 km means there is very little relief built into the profile — almost every kilometre is doing real work. The total ascent of 1237 m is close to the net gain of 1261 m, which tells you the climb rises almost monotonically, with barely any downhill or false-flat to give the legs a breather. What breaks up the monotony is severity, not rest: the pitch to 27.31% is more than 17 percentage points steeper than the average, so you can expect ramps where cadence collapses and you are simply trying to keep the bike moving in a straight line. Read the road ahead, and treat every steep section as a stretch to survive rather than attack.

Pacing Notes

On a climb this long and this steep, pacing by feel is a trap. Anchor your effort to your FTP and hold something you can genuinely sustain for the better part of an hour, because at 9.87% over 12.8 km there is nowhere to soft-pedal and recover. If you do not know your threshold, run the numbers first with the FTP estimator so you are not guessing on the lower slopes and blowing up before the summit. The steep ramps toward 27.31% will spike your power well above threshold whether you like it or not — accept those surges, then settle back down immediately afterward. The riders who make it up cleanly are the ones who bank patience early and spend it only when the gradient forces their hand.

Gearing

Do not under-gear this one. With an average of 9.87% and ramps to 27.31%, a compact chainring paired with a wide cassette is the sensible floor. A 34×32 will get most fit riders up, but on the steepest pitches you will be grinding at a cadence that shreds the legs over 12.8 km. If your derailleur allows it, go to a 34×34 for a little more headroom, and be honest about your climbing power — carrying a rescue gear on an HC ascent is never the wrong call.

Summary

The Passo delle Lame is a relentless HC test: long, uniformly steep, and topped with walls that demand your easiest gear. Pace it against your threshold, gear generously, and let patience carry you to the summit.

Length: 12.8 km
Average gradient: 9.87%
Max gradient: 27.31%
Start: 122 m
Summit: 1383 m
Net gain: 1261 m
Total ascent: 1237 m
Category: HC