Colle della Croce

Colle della Croce cycling climb profile

Colle della Croce is an HC climb in France, and the classification makes sense once the full profile is viewed as a workload problem rather than just a gradient number. The climb runs for 34.3 km, starting at 403 m and topping out at 2221 m, with 1818 m of net elevation gain. The average gradient is 5.3%, which sounds manageable in isolation, but that figure is spread across a very long ascent and hides the decisive detail: the maximum gradient reaches 27.01%.

That combination shapes how the climb should be ridden. This is not a short wall where the steepest section defines the whole effort, and it is not a steady alpine tempo climb where one gear and one power target can carry you cleanly to the top. The average tells you the climb is prolonged and aerobic. The maximum tells you it has sections steep enough to punish poor pacing, bad gear selection, or any early enthusiasm that pushes you over your limit.

How the gradient unfolds

From bottom to summit, the main story is duration with spikes. The climb gains elevation for more than thirty kilometres, so even if much of the ascent sits near the overall 5.3% average, the body cost accumulates steadily. The 27.01% maximum gradient means the profile is not uniform. Somewhere in the ascent, the road kicks far above the average, and those ramps change the tactical demands.

The practical interpretation is simple: do not pace this as a smooth 5.3% climb. Pace it as a long endurance climb with the possibility of very steep interruptions. If you ride the easier gradients too hard, the steep ramps become forced anaerobic efforts. If you stay controlled early, those same ramps are still hard, but they become manageable surges rather than race-ending mistakes.

Pacing and gearing notes

Use a sustainable climbing effort from the start, ideally anchored around your known climbing power or /glossary/ftp rather than speed. Speed will vary too much with gradient, especially on the steepest pitches, so chasing it is a poor guide.

Gearing should be chosen for the maximum gradient, not the average. A setup that feels comfortable at 5.3% may be too heavy when the road pitches into the severe ramps. The goal is to preserve cadence and avoid grinding at low torque for extended periods, because that creates muscular fatigue that will be difficult to recover from on a climb this long.

How to ride it well

• Start below threshold and let the climb come to you.
• Treat the steepest sections as controlled surges, not attacks.
• Shift early before the gradient bites.
• Keep fueling and drinking from the lower slopes, because the climb is long enough for small mistakes to compound.
• Save a gear and a little power reserve for the upper half, where fatigue makes every ramp feel steeper.

Colle della Croce rewards discipline. The average gradient invites confidence, but the length and 27.01% maximum gradient punish riders who mistake the headline number for the whole climb.