French Alps, France · from Guillestre

Col d'Izoard

The Izoard from Guillestre climbs the Guil gorge before the long, steady grind through pine forest to the Casse Déserte, a surreal amphitheatre of scree and rock pinnacles just below the 2,360 m summit. Few climbs combine racing pedigree and scenery like this one.

Length
30.4 km
Elevation gain
1410 m
Avg gradient
4.6%
Steepest section
10.7%

Summit elevation: 2360 m

How fast would you climb Col d'Izoard?

Enter your power and weight. A physics engine calculates your estimated time against the gradient profile.

Physics Engine

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performance.

See how power and weight affect your time on a real climb.

250 W
75 kg
Col d'Izoard (Simulated)
Est. Time
Set your FTP & weight, then predict
Recovery Threshold VO2 Max

*Demo simulation uses standard road bike physics (CdA 0.32, Crr 0.004).

Col d'Izoard and the Tour

An Izoard crossing was for decades the signature of Tour legends: Fausto Coppi and Louison Bobet both soloed through the Casse Déserte to famous victories, and a memorial to the two riders is set into the rock there.

The Izoard hosted its first Tour summit finish in 2017, won by Warren Barguil. It also features regularly in the Giro-style Route des Grandes Alpes and the Granfondo calendar; pros climb this side in around 45 minutes.

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Riding it yourself

When to go

Open June to October. The southern approach is hot and exposed in high summer — start early; the Casse Déserte section radiates heat in the afternoon.

Base & logistics

Guillestre is the base for this southern side, Briançon for the north. Water in Arvieux and at the refuge below the summit. The classic link is Izoard + Col de Vars, or over to Briançon for the Galibier group.

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FAQ

How long is the Col d'Izoard climb?

From Guillestre, the climb is about 30.4 km with roughly 1410 m of elevation gain at 4.6% average gradient (based on the simplified profile used by this simulator; published figures vary slightly by source).

How long does it take to cycle up Col d'Izoard?

It depends almost entirely on your power-to-weight ratio. Use the simulator on this page: enter your FTP and weight, and a physics model (air resistance, rolling resistance, gravity) estimates your time on the gradient profile.

How accurate is the time simulation?

The simulator uses a simplified segment profile and standard road bike assumptions (CdA 0.32, Crr 0.004, 8 kg bike). It does not model wind, drafting, altitude, surface or pacing errors, so treat the result as a realistic estimate, not a guarantee.

How should I train for Col d'Izoard?

Sustained climbs reward steady threshold and sweet spot work plus a power-to-weight improvement over weeks, not days. TrainCraft builds structured cycling training plans and adapts them when you miss sessions, using fatigue science (CTL/ATL/TSB).

More famous climbs

Preparing for this climb?

A climb like this is won weeks in advance. TrainCraft builds a structured plan around your FTP and available hours, and adapts it when you miss a workout.

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The profile is simplified into 58 segments for simulation; real gradients vary metre by metre. Stats shown are derived from this simulated profile and closely match commonly published figures. Time estimates assume standard road bike physics and no wind.

Training for a climb like this?

TrainCraft builds structured training plans and adapts them when life gets in the way — real fatigue science (CTL/ATL/TSB), visual workout builder, Strava & Garmin sync. Free to start.