Col de l'Encrenaz

Overview

The Col de l'Encrenaz is a climb defined by its length rather than its ferocity. Stretching 36.5 km from a valley floor at 569 m to a summit at 2187 m, it demands patience above all else. The average gradient of 4.44% sounds gentle on paper, and in isolation any single kilometre might be. But laid end to end across 36.5 km, that modest slope accumulates into 1618 m of net elevation gain and 1646 m of total ascent — a category 1 effort that rewards riders who treat it as a long tempo day rather than a short, sharp fight.

How the Gradient Unfolds

At 4.44% average, the Encrenaz is not a wall; it is a ramp that simply refuses to end. The small gap between the net gain of 1618 m and the total ascent of 1646 m tells the real story: only 28 m of the climb is lost to descending or false-flat dips. In practice that means the road tilts upward almost continuously, with very little respite where you can freewheel and recover. Expect long, steady stretches close to the average, punctuated by pitches that sit a little above 4.44% and shallower sections that feel almost flat by comparison. Because the summit sits at 2187 m, the final kilometres also carry the thinning air of high altitude, which quietly sharpens every percent of gradient.

Pacing Notes

On a climb this long, pacing is everything. The 36.5 km distance means efforts that feel sustainable in the first 10 km can unravel badly by the summit. Aim to ride the bulk of the climb comfortably below your threshold — for most riders that means holding a percentage of FTP you could maintain for well over an hour. If you do not know your number, run it through the FTP estimator before you commit to a target power. With 1618 m of climbing to cover, the difference between a well-judged pace and an over-ambitious one is measured not in seconds but in whole minutes lost near the top.

Gearing

Because the Encrenaz trades steepness for duration, you want gearing that protects your legs over the long haul rather than gearing for survival on ramps. A compact 34-tooth inner chainring paired with a 34×32 cassette gives most riders enough range to spin the steeper pitches without grinding. If you tend to climb at a lower cadence, weigh less against the mountain, or simply want insurance for the high-altitude finish, step up to a 34×34 — the extra sprocket costs nothing on the shallow sections and pays for itself over 36.5 km.

Summary

The Col de l'Encrenaz is a test of endurance and pacing discipline: 36.5 km of near-continuous 4.44% gradient, topping out at 2187 m. Respect the distance, mind your pacing, and gear generously.

Length: 36.5 km
Average gradient: 4.44%
Max gradient: n/a
Start: 569 m
Summit: 2187 m
Net gain: 1618 m
Total ascent: 1646 m
Category: 1