Col de Perty

Overview

Col de Perty is a Category 2 climb in France, running 13.6 km from a start elevation of 657 m to a summit at 1,284 m. The net elevation gain is 627 m, which produces a modest average gradient just above 4.6%. On paper that reads as a steady, manageable ascent — the kind of climb you can settle into without drama.

The paper number is misleading. While the net gain is 627 m, the total ascent over the full 13.6 km is 1,228 m. That gap of roughly 601 m of "extra" climbing tells you the road undulates: it gives back height in descents and false flats that you then have to reclaim. The effort is therefore lumpier than the average suggests. You will spend real energy on pitches that do not show up in a start-to-summit gradient calculation, so treat this as a rolling climb rather than a smooth grind.

How the Gradient Unfolds

The average gradient of 4.6% is a blend, not a constant. With more than 1,228 m of total ascent packed into a climb that only nets 627 m, the profile hides both recovery terrain and sharp, concentrated efforts. The steepest ramp reaches 22.07% — far above anything the average hints at.

• Flatter and downhill recovery sections where you can spin, drink, and reset
• Repeated short climbs that stack up the total ascent well beyond the net gain
• A punishing steepest ramp near 22% that demands a low gear and a seated, controlled effort

Pacing Notes

On a smooth climb you can chase even effort and let speed vary. On Col de Perty, the undulation forces a choice. Even-effort pacing is the smarter target here: hold a steady output through the descents and false flats rather than surging to "make up time." Chasing even speed on the steep pitches will spike you well past your sustainable power output and cost you on the ramps that follow.

Use the flatter and downhill sections to recover, not to attack. Before the ride, calibrate your target with the FTP estimator so you know the ceiling you should not breach on that 22% wall.

Gearing

The steepest gradient governs your setup, and at 22.07% that is decisive. Run a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 combination gives you the low ratio needed to keep cadence on the steepest ramp without grinding to a stall. Do not leave this to chance: check your chainrings and cassette before the ride, and confirm the derailleur handles the largest sprocket cleanly.

Summary

• Length: 13.6 km
• Average gradient: 4.61%
• Maximum gradient: 22.07%
• Net elevation gain: 627 m
• Total ascent: 1,228 m
• Category: 2

Col de Perty rewards riders who read the profile, not just the average. Pace to effort, gear for the 22% ramp, and respect the extra 601 m of climbing that the net figure conceals.