Gros Mont

Gros Mont cycling climb profile

Gros Mont is a Category 1 climb that asks for patience more than heroics. On paper, 9.8 km at 7.2% is not extreme in length, but the combination of a sustained average gradient and a maximum gradient of 13.3% makes it a climb where pacing errors become expensive.

The road starts at 988 m and rises to 1692 m, with 704 m of net elevation gain. That tells the important story: this is not a rolling approach dressed up as a climb. The average gradient is doing real work here. Across nearly 10 km, 7.2% is steep enough that most riders will spend the majority of the ascent seated, managing torque and breathing rather than trying to float over the road.

How the gradient unfolds

The available profile data does not give detailed kilometre-by-kilometre splits, so the right way to read Gros Mont is as a sustained climb with sharper sections embedded inside it. The 7.2% average sets the baseline effort, while the 13.3% maximum gradient is the warning sign: somewhere on the ascent, the road kicks hard enough to punish riders who have been riding above threshold.

That matters tactically. A climb with this profile rewards a controlled start because the steepest ramps are almost double the average gradient. If you treat the early kilometres like a tempo climb and ride slightly under control, you have room to absorb the steeper pitch without blowing through your sustainable power. If you chase speed too early, the 13.3% section becomes the point where cadence drops, torque spikes, and the final part of the climb turns into damage control.

Pacing and gearing notes

Ride Gros Mont by effort, not by speed. The gradient is steep enough that speed will fluctuate sharply with small changes in pitch, especially when the road approaches its maximum gradient. Use your /glossary/ftp as the ceiling rather than the target if you are riding the full climb hard. For most riders, the smartest execution is a steady sub-threshold effort through the opening portion, then a controlled lift only once the summit feels genuinely close.

Gearing should be chosen for the steepest part, not the average. A 7.2% average can look manageable, but a 13.3% maximum gradient demands a bailout gear that lets you keep pressure smooth rather than grinding at low cadence. If you are overgeared, Gros Mont becomes less about aerobic capacity and more about muscular fatigue, especially after several kilometres of sustained climbing.

The cleanest way to ride it is simple: settle early, keep cadence stable, avoid chasing every change in pitch, and save enough margin for the ramps. Gros Mont is long enough to expose impatience and steep enough to make gearing matter.