Col de Champillon

Overview

The Col de Champillon is a genuine hors catégorie test, and the numbers make no apologies for it. Over 27.3 km the road gains 1866 m of net elevation, starting at 555 m and topping out at a lofty 2421 m. The average gradient reads 6.83%, but averages flatter the reality of a climb this long — with a max pitch of 15.98%, there are moments here that will empty your legs if you arrive at them already deep in the red. The total ascent of 1843 m confirms this is almost all climbing, with only the smallest breather of downhill mixed in.

How the Gradient Unfolds

At 27.3 km, this is a climb measured in phases rather than minutes. A 6.83% average across that distance means you are rarely on flat ground and never truly recovering. The gap between the 6.83% average and the 15.98% maximum is where the character lives: expect the road to sit comfortably in the mid-single digits for long stretches, then rear up into double-digit ramps that force a decision — grind or shift. Because total ascent (1843 m) sits just below net gain (1866 m), there is almost no false-flat relief to reset your legs. What goes up keeps going up, and the thin air near the 2421 m summit sharpens every ramp in the final kilometres.

Pacing Notes

On a climb this size, discipline beats bravado. The single most useful reference is your FTP — for an effort that may stretch well beyond an hour, most riders should settle in below threshold, closer to a sustainable tempo, and save any surges for the steepest pitches. If you do not know your number, run a quick check with the FTP estimator before you commit to a target. The trap on the Champillon is the opening kilometres feeling manageable at 6.83%; ride them by feel and the 15.98% sections higher up will exact interest with the altitude working against you. Meter your effort so the last few kilometres toward 2421 m are the ones you finish, not the ones that finish you.

Gearing

Gear for the ramps, not the average. A 6.83% mean gradient is spinnable on almost anything, but the 15.98% maximum combined with 1866 m of cumulative fatigue is what dictates your setup. A compact 34-tooth chainring paired with a 34×32 low is the sensible baseline for strong climbers; anyone who wants to protect their knees over 27.3 km, or who climbs at a lower cadence, should not hesitate to go to a 34×34. On an HC climb of this length, the extra range is insurance, not indulgence — a bailout gear keeps you turning the pedals when the road hits its steepest.

Summary

The Col de Champillon rewards patience, a well-chosen gear, and honest pacing. Respect the 27.3 km, ride within yourself early, and the summit at 2421 m is well within reach.

Length: 27.3 km
Average gradient: 6.83%
Max gradient: 15.98%
Start: 555 m
Summit: 2421 m
Net gain: 1866 m
Total ascent: 1843 m
Category: HC