Col des Annes

Overview

Col des Annes sits in the French Alps and carries a Category 2 classification despite an average gradient of just 3.24% across its 20.9 km. That number is misleading. The climb racks up 2,364 m of total ascent against a net elevation gain of 677 m — a gap that signals significant undulation, punchy ramps, and sections of genuine relief built into the road. The maximum recorded gradient of 50.48% is an outlier figure, likely a short-lived ramp rather than a sustained wall, but it underscores the need to stay alert even when the average feels manageable.

Start elevation sits at 1,083 m; the summit reaches 1,760 m.

How the Gradient Unfolds

The 677 m net gain spread over 20.9 km produces an average that would feel modest on a steady mountain road. But the 2,364 m of total ascent tells a different story: the road repeatedly climbs, eases, and climbs again. Expect the lower flanks to lull you into a comfortable tempo before steeper ramps interrupt the rhythm further up.

The maximum gradient of 50.48% is extreme enough that it almost certainly represents a very brief pinch point — a tight hairpin exit or a short road-surface anomaly. No rider will sustain anything close to that figure. Nonetheless, sharp transitions from flat or descending segments into steep ramps are the defining challenge here. Because the road gives back altitude periodically, your legs never fully accumulate fatigue in a linear way, but neither do they get consistent rest.

Key Gradient Zones to Anticipate

• Lower section: Moderate gradients in line with or below the 3.24% average — use this to settle breathing and establish a sustainable power output.
• Mid-climb ramps: Steeper pitches interrupt the false flat rhythm; these are where riders who went too deep early start to suffer.
• Upper section: The cumulative fatigue from repeated surges across 20+ km begins to tell. Pacing discipline from the bottom pays off here.
• The maximum-gradient pinch: Treat it as a short technical feature — shift early, keep cadence high, and don't panic-sprint through it.

Pacing & Power Strategy

Because the average gradient is low but total ascent is high, average-power targets based on FTP can be deceptive. A target of 75–85% FTP might feel comfortable on the flatter stretches but leave you undercooked for the steeper ramps — or, if you push through the ramps at threshold, you accumulate debt that costs time on the subsequent drags.

The recommended approach:

1. Anchor to a ceiling, not a floor. Set a maximum power limit for the steep ramps — perhaps 105–110% FTP for no more than 30–60 seconds — and resist the urge to go harder, even when it feels easy.
2. Use the flatter and descending segments to recover actively, not to push pace. Soft-pedal or spin at low resistance to clear lactate before the next ramp arrives.
3. Use the FTP estimator before targeting this climb if you haven't tested recently. A stale FTP number will skew every power zone.

Gearing Notes

At 20.9 km with a maximum gradient approaching the physical limits of road surfaces, a compact chainset (50/34 or 46/33) paired with an 11-32 or 11-34 cassette is strongly advisable. The sustained length means you will spend real time on the steeper pitches rather than sprinting through them. Grinding a gear that is even slightly too large across repeated ramps over this distance accelerates muscular fatigue disproportionately.

If you are running a standard 53/39 setup, ensure your cassette gives you at least a 28-tooth low gear; anything tighter risks blowing up on the maximum-gradient sections.

Bottom Line

Col des Annes is a Category 2 climb that punishes complacency. The low average gradient invites optimistic early pacing; the high total ascent and extreme maximum gradient punish it. Ride it like a long, broken climb — not a gentle cruise.