Colle della Muraille Rouge

Overview

The Colle della Muraille Rouge is a hors catégorie (HC) climb, the hardest category on the scale before you drop to 1, 2, 3 and 4. What earns it that rating is not a single savage wall but sheer relentlessness: 29.2 km of continuous climbing from a valley floor at 578 m to a summit at 2274 m. That is 1696 m of net elevation gain, with 1693 m of total ascent — the two figures sitting almost on top of each other, which tells you the road climbs and keeps climbing rather than dipping and recovering. At an average gradient of 5.81%, no individual kilometre looks intimidating on paper. The difficulty is the sum, not the parts.

How the Gradient Unfolds

With total ascent (1693 m) and net gain (1696 m) essentially identical, there is almost no descending built into these 29.2 km. Every metre you climb, you keep. A climb this long at 5.81% is best understood as a machine that never switches off. Because the average is moderate, expect the road to breathe: stretches gentler than 5.81% that let you settle, offset by stretches steeper than the mean that claw the average back up. The final push toward 2274 m matters most — thin air above 2000 m makes any pitch feel harder than the gradient number suggests, so treat the closing kilometres with more respect than the profile alone implies.

Pacing Notes

On a climb of 29.2 km, discipline beats bravado. Riding steady near your FTP — or a touch below for anything but a race — is the only way to reach 2274 m without blowing apart. The trap is the gentle opening gradients: they invite an effort you cannot sustain for 1696 m of climbing. If you do not know your threshold, run the numbers through the FTP estimator before you commit, then hold a wattage you could theoretically maintain for the full length. Fuel early and often; 1696 m of vertical is a long time in the saddle, and glycogen runs out well before the summit does.

Gearing

For an HC climb of this length, gear low and gear generously — you will thank yourself in the final third. A compact 34-tooth chainring is the sensible front choice. Pair it with at least a 34×32, which gives most riders enough range to spin the average 5.81% pitches without grinding. If you carry any fatigue, run bigger climbs regularly, or expect the steeper-than-average ramps near 2274 m to bite, step up to a 34×34. On a climb where survival is measured across 29.2 km, the extra sprocket is cheap insurance against a blown cadence.

Summary

The Colle della Muraille Rouge rewards patience over power. Meter your effort, gear low, fuel early, and let its 29.2 km unspool at a rhythm you can hold to 2274 m.

Length: 29.2 km
Average gradient: 5.81%
Max gradient: n/a
Start: 578 m
Summit: 2274 m
Net gain: 1696 m
Total ascent: 1693 m
Category: HC