Col du Chasseral

Overview

The Col du Chasseral is a category 1 ascent that covers 15.6 km at an average gradient of 6.85%, lifting you from a start elevation of 434 m to a summit at 1501 m. That works out to 1067 m of net elevation gain, with 1054 m of total ascent packed into the climb. On the five-tier scale — where HC (hors catégorie) is the hardest, followed by 1, 2, 3, and 4 — a category 1 rating tells you this is a serious, sustained effort that demands real respect but sits just below the very toughest passes.

How the Gradient Unfolds

At 6.85% average over 15.6 km, Chasseral never really lets you settle into an easy rhythm. The defining feature is the gap between the 6.85% mean and the 14.33% maximum: that spread of 7.48 percentage points means the climb is far from uniform. Expect long stretches close to the average punctuated by pitches that spike toward the double-digit maximum. Because the net gain of 1067 m is slightly larger than the 1054 m of total ascent, the road climbs almost continuously — there is very little false-flat or descending relief to recover on. Plan your effort around the steep ramps, not the average.

Pacing Notes

The smartest way to ride a 15.6 km climb of this length is to anchor your effort to your FTP. Hold a steady, sustainable power on the stretches near 6.85%, and let your effort rise only on the ramps toward 14.33% — surging early will cost you dearly over the back half. If you do not know your threshold power yet, run the numbers through the FTP estimator before you commit to a target, then aim to spend the bulk of the climb just under that line. With 1067 m of vertical to gain, discipline in the opening kilometers pays off all the way to 1501 m.

Gearing

For a category 1 climb averaging 6.85% and spiking to 14.33%, gearing that lets you keep a comfortable cadence on the steepest pitches is essential. A compact 34-tooth inner chainring paired with a 34×32 low gear will handle most of the climb, but if you are carrying fatigue or ride at a lower cadence, step up to a 34×34 for extra margin on the ramps approaching the 14.33% maximum. On a climb this long, spinning a slightly easier gear is almost always faster than grinding.

Summary

Col du Chasseral is a sustained category 1 test: 15.6 km at 6.85%, with steep ramps toward 14.33% and 1067 m of climbing to a 1501 m summit. Pace to your threshold, gear low, and respect the pitches.

Length: 15.6 km
Average gradient: 6.85%
Max gradient: 14.33%
Start: 434 m
Summit: 1501 m
Net gain: 1067 m
Total ascent: 1054 m
Category: 1