Col du Séchet

Overview

The Col du Séchet is a long, serious category 1 ascent that rewards patience and punishes the impatient. Over 16.6 km it climbs from a valley floor at 803 m to a summit at 1828 m, a net gain of 1025 m. The headline average of 6.16% sounds civil, and for long stretches it is — but that number hides a savage 31.78% maximum pitch that turns one section of this climb into something closer to a wall than a road. At more than sixteen kilometres, this is a climb you settle into for the better part of an hour, not a short blast.

How the Gradient Unfolds

Two numbers tell the story: a 6.16% average against a 31.78% max. That gap is enormous. It means the climb is not evenly graded — a sustained 6% effort strung between passages that are far gentler and at least one ramp steep enough to stall a rider who arrives in the wrong gear or at the wrong pace. The net elevation gain of 1025 m against a total ascent of 984 m confirms there is real vertical work here with only minor undulation; the road climbs almost the entire way rather than rolling. Treat the average as a planning figure and the max as a warning: your legs will feel both, and the transitions between them are where the climb is won or lost.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to a fraction of your FTP rather than to how you feel in the first kilometre — the summit is 16.6 km away and 1025 m up, and early over-exertion compounds badly over that distance. If you do not know your threshold, run the numbers through the FTP estimator before you plan. Sit slightly below threshold on the 6.16% sections, keep a reserve for the 31.78% ramp, and let cadence — not ego — dictate your speed when the road tilts up. Fuel and drink early; the effort here is long enough that bonking is a real risk on the upper slopes.

Gearing

The 6.16% average is manageable on standard road gearing, but the 31.78% max makes the case for the widest cassette you can fit. On a compact chainset, a 34×32 will get most trained riders to the summit, but for the steepest ramp — and for the accumulated fatigue of 1025 m of climbing — a 34×34 gives you a genuine bailout gear. If your derailleur accepts it, choose the 34×34: spinning a low gear up the wall costs far less than grinding it. Err on the side of easier here.

Summary

The Col du Séchet is a full-length category 1 test: long enough to demand pacing, steep enough in one place to demand respect, and best met with low gears and a cool head.

Length: 16.6 km
Average gradient: 6.16%
Max gradient: 31.78%
Start: 803 m
Summit: 1828 m
Net gain: 1025 m
Total ascent: 984 m
Category: 1