Col de Blanchard

Overview

Col de Blanchard is a hors catégorie climb that earns its rating the honest way — through relentless steepness rather than sheer length. Over 11.6 km it averages 9.32%, dragging you from a start elevation of 381 m up to a summit of 1464 m. That works out to 1083 m of net elevation gain, with 1046 m of total ascent packed into a single sustained push. There is no easing gradient to hide behind here: an average this high across a climb this long means the road tilts steeply from the bottom and rarely relents. Add a maximum gradient of 17.04% and you have a climb that punishes anyone who starts too hard.

How the Gradient Unfolds

The defining number is that 9.32% average. On most climbs an average is diluted by flatter sections and false flats; on Blanchard, with a max of only 17.04%, the spread between average and maximum is narrow. That tells you the gradient stays clustered near double digits for most of its 11.6 km rather than swinging between shallow recovery and brutal walls. Expect long stretches sitting close to or above the average, with the steepest ramps toward 17.04% arriving as sharp stings rather than isolated freak pitches. The near-identical net gain (1083 m) and total ascent (1046 m) confirm there is almost no descending or flat respite — nearly every metre you climb, you keep.

Pacing Notes

Discipline wins this climb. Because the gradient sits so consistently near 9.32%, your power output will be steady and unforgiving — there are no soft-pedal moments to recover. Anchor your effort to your FTP and aim to spend the lower half at or just below threshold, holding a little in reserve for the steepest ramps near 17.04%. If you don't know your threshold power, run the numbers first with the FTP estimator so you're pacing to real data, not feel. A climb of 11.6 km at this gradient rewards riders who ration effort evenly; go into the red early and the final kilometres toward 1464 m will unravel you.

Gearing

Gear for survival, not pride. With a 9.32% average and pitches to 17.04%, most riders will want the widest cassette they can fit. A compact 34-tooth chainring paired with a 34×32 setup is the sensible baseline for a fit climber, giving you a low enough ratio to spin the sustained steep sections without grinding to a stall. If you weigh more, ride at endurance pace, or simply want insurance against the 17.04% ramps late in the 11.6 km, step up to 34×34. On an HC climb this steep, an extra sprocket is never wasted — it keeps your cadence up and your knees intact.

Summary

Col de Blanchard is a compact, uncompromising HC climb: steep from the base, steep through the middle, and steep to the line at 1464 m. Pace it to your threshold, gear low, and respect the fact that the average is almost the whole story.

Length: 11.6 km
Average gradient: 9.32%
Max gradient: 17.04%
Start: 381 m
Summit: 1464 m
Net gain: 1083 m
Total ascent: 1046 m
Category: HC