Col de Planchamp

Overview

Col de Planchamp is a hors catégorie (HC) climb — the hardest classification on the scale, sitting above categories 1 through 4. Over 22.7 km it lifts you from a start elevation of 392 m to a summit at 1990 m, an average gradient of 7.04%. That headline number hides the real story: with a maximum pitch of 28.5%, this is a climb defined by its violent swings rather than any steady rhythm. The net elevation gain is 1598 m, but the total ascent of 1660 m tells you the road briefly gives back before clawing higher again.

How the Gradient Unfolds

At 22.7 km, Planchamp is long enough that pacing errors compound badly. The difference between the total ascent (1660 m) and the net gain (1598 m) — 62 m — means there are false flats or short descents where you can recover, but they are the exception. The defining feature is the max gradient of 28.5%, more than four times the average of 7.04%. A wall like that is not something you power over on feel; it arrives, spikes your effort far beyond sustainable output, then releases. Expect the climb to alternate between grades near the 7% average and sharper ramps that drag the average upward. The last stretch toward 1990 m is where accumulated fatigue meets thinning air.

Pacing Notes

On a climb this long, discipline beats ambition. Anchor your effort to your FTP and hold something in reserve for the steep ramps, because every surge toward 28.5% costs you more than the time you save. If you do not know your current threshold, run the numbers through the FTP estimator before you commit to a target. A good rule for Planchamp: ride the 7.04% sections a touch below what feels comfortable so you have headroom when the gradient doubles. Fueling matters over 22.7 km — an hour-plus of climbing is an eating problem as much as a power problem.

Gearing

Do not under-gear this one. The 28.5% max gradient punishes anyone spinning out of low ratios, and 22.7 km of sustained 7.04% climbing wears down whatever you have left. A compact 34-tooth chainring paired with a 34×32 low gear is the sensible floor for strong climbers; most riders will be happier with 34×34, which buys precious cadence on the walls. If your setup allows something lower still, use it — on an HC climb with 1598 m of net gain, there is no prize for grinding.

Summary

Col de Planchamp earns its HC label honestly: 22.7 km, an average of 7.04%, ramps to 28.5%, and 1598 m of vertical between 392 m and 1990 m. Pace it to your threshold, gear low, and treat the steep pitches with respect.

Length: 22.7 km
Average gradient: 7.04%
Max gradient: 28.5%
Start: 392 m
Summit: 1990 m
Net gain: 1598 m
Total ascent: 1660 m
Category: HC