Col du Lein

Overview

Col du Lein is an HC climb in Switzerland, rising 13.9 km from a start elevation of 456 m to a summit at 1,687 m. Over that distance it delivers a net elevation gain of 1,231 m at an average gradient of 8.88%. That average alone puts it firmly in the hardest category — a sustained wall of climbing with no easy version of the day.

The average, though, undersells the work. Net gain is 1,231 m, but total ascent is 1,795 m. That 564 m gap means the road repeatedly gives back altitude and forces you to reclimb it. You are not paying for 1,231 m of vertical — you are paying for 1,795 m of pedaling, spread across descents and false flats that break rhythm and reset your legs at the worst moments.

How the Gradient Unfolds

The 8.88% average is a blend, not a constant. Undulation drags the mean down, which means the climbing sections sit well above 8.88% to compensate for every meter lost on the dips. Expect the steepest ramp to bite hard — up to 32.59% — a pitch that no amount of even pacing will smooth over.

• Flatter or descending recovery sections that account for the 564 m of extra ascent
• Repeated short climbs that punch above the stated average
• A brutal steepest ramp reaching 32.59%, where cadence collapses and it becomes a raw force effort

Pacing Notes

On a climb this lumpy, even-speed pacing will wreck you — holding a fixed speed means spiking your power on every ramp. Pace to even effort instead: hold a steady sustainable power output through the climbs and soft-pedal the descents rather than chasing time back. Let the flatter sections be genuine recovery. Because the gradient swings so widely, knowing your ceiling matters — run the FTP estimator beforehand so you have a hard number to pace against and do not blow up on an early ramp.

Gearing

The 32.59% steepest pitch dictates everything about your setup. A standard compact will not be enough here. Fit a sub-compact chainset and a wide-range cassette — a 34×32 at minimum, and 34×34 if you can run it — so you keep a turnable cadence when the road stands up. Check your chainset and cassette before the ride, not at the base of the climb.

Summary

• Length: 13.9 km
• Average gradient: 8.88%
• Maximum gradient: 32.59%
• Net elevation gain: 1,231 m
• Total ascent: 1,795 m
• Category: HC

Col du Lein is a genuine HC effort where the numbers on paper — 13.9 km at 8.88% — hide the real cost. Respect the 564 m of extra climbing, gear low for the 32.59% ramp, and pace to effort. Do that, and the summit at 1,687 m is yours.