Col de Jable

Overview

Col de Jable is a category-HC climb in Switzerland, running 11.1km from a valley start at 917m to a summit at 1894m. The net elevation gain is 977m, and the average gradient across the full ascent is 8.8%. On paper that is a relentless, near-9% grind for over eleven kilometres — a climb that earns its HC rating on sustained difficulty alone.

But the profile is not a clean staircase. The total ascent recorded on the road is 1346m, against a net gain of only 977m. That 369m gap is climbing you do twice: descents and false flats that give back altitude, then reclaim it. Every metre of that re-climbing costs energy that never shows up in the net figure, so the effort is meaningfully harder than a smooth 977m gain would suggest. Pace it like a straight climb and the undulations will bury you.

How the Gradient Unfolds

The 8.8% average is a blend, not a constant. Undulation of nearly 370m means the road repeatedly dips and kicks, so some sections sit well below average while the ramps that follow run far steeper to compensate. Where the profile flattens or drops, the true climbing pitches have to be sharper than 8.8% to keep the average intact.

• Flatter and recovery sections where the road eases or briefly descends
• Repeated short climbs that reclaim altitude given back on the dips
• Steeper ramps stacked after the false flats, biting harder than the average implies

Pacing Notes

On a smooth climb you pace to even effort and let speed vary. On Col de Jable, the undulation forces a choice, and even effort wins. Hold a steady sustainable power output through the ramps and let your speed rise on the recovery dips rather than surging to hold a target pace. Chasing even speed on the steep pitches will spike you well over threshold and cost you on the upper slopes.

Know your number before you start. Use the FTP estimator to set a ceiling, then ride the steepest ramps just under it and use the flatter sections to recover, not to push.

Gearing

With an average near 9% over 11.1km and ramps that run steeper still, gearing is not optional. Run a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you the low end to spin the steep pitches instead of grinding them. Confirm your chainset and cassette before the ride; discovering you are over-geared halfway up an HC climb is a long, painful way to learn.

Summary

• Length: 11.1km
• Average gradient: 8.8%
• Net elevation gain: 977m
• Total ascent: 1346m
• Category: HC

Col de Jable is an HC climb that rewards discipline. Respect the 369m of hidden re-climbing, pace to even effort, gear low, and the summit at 1894m is yours.