Col du Tacul

Overview

Col du Tacul is a long climb that rewards patience over power. Stretching 24 km from a base at 828 m to a summit of 1985 m, it delivers a net elevation gain of 1157 m at an average gradient of 4.82%. That average tells only part of the story: with 24 km on the clock, this is a sustained effort measured in tens of minutes rather than a short punchy test, and its category 1 rating places it among the harder graded climbs, one rung below the fearsome hors catégorie.

The headline number to respect is the 20.2% maximum gradient. A pitch that steep on an otherwise moderate climb signals a road that refuses to settle into a rhythm, so treat the 4.82% average as a planning tool, not a promise.

How the Gradient Unfolds

With a 4.82% average across 24 km but a spike to 20.2%, the Col du Tacul is a climb of contrasts. The gap between the summit elevation of 1985 m and the start at 828 m is 1157 m of net gain, yet the recorded total ascent is 1087 m. That difference tells you the road is not a clean, monotonic drag upward — there are flatter breaths and likely brief descents woven into its length that let your legs recover between the harder ramps.

Expect the effort to come in waves. The gentle average is a mathematical smoothing of easy kilometres against savage single-digit-to-twenty-percent ramps. Read the road ahead, sit up on the shallow sections, and save your matches for the pitches that climb toward that 20.2% ceiling.

Pacing Notes

On a 24 km climb, discipline beats bravado. Anchor your effort to your sustainable threshold rather than the mood of any single ramp. If you know your FTP, hold just under it on the steady 4.82% stretches and allow yourself to surge briefly over the steep pitches, knowing the flatter sections will let you clear the debt. If you are unsure of your number, the FTP estimator will give you a working figure to pace against.

The 20.2% max is the one place discipline can slip — riders panic, stand, and burn far too much too early. Shift down before the ramp, not on it, and let cadence carry you over.

Gearing

Gearing is what separates a controlled ascent from a survival crawl here. The combination of 24 km of climbing and a 20.2% maximum gradient means you want low gears in reserve. A compact 34-tooth chainring paired with a wide-range cassette is the sensible foundation.

A 34×32 will get most fit riders over the steep pitches while keeping cadence respectable on the 4.82% average sections. If you climb at a lower cadence, carry extra weight, or simply want insurance against that 20.2% wall, step up to a 34×34. The extra teeth cost you almost nothing on the shallow parts and buy real comfort when the road kicks up.

Summary

Col du Tacul is a long, uneven category 1 climb that hides real bite behind a modest 4.82% average. Pace it to your threshold, gear low for the 20.2% ramps, and let the flatter kilometres do the recovering. Respect the 1157 m of vertical between base and summit and it becomes a satisfying test rather than a slog.

Length: 24 km
Average gradient: 4.82%
Max gradient: 20.2%
Start: 828 m
Summit: 1985 m
Net gain: 1157 m
Total ascent: 1087 m
Category: 1