Col de Roux

Col de Roux cycling climb profile

The Col de Roux is an HC climb in Switzerland built around one defining demand: duration. At 28 km, with a listed average gradient of 6.84%, it is not a climb to treat as a sequence of isolated ramps. It is a long sustained effort where the main tactical problem is how to keep the power under control early enough to still ride efficiently near the top.

The road starts at 498 m and reaches 2416 m, with a listed net elevation gain of 1918 m. That vertical difference matters because it tells you the climb is not just long on the map. It keeps asking for work almost all the way to the summit. The listed total ascent is 1894 m, while the maximum gradient reaches 11.64%, so even if the average sits below the psychologically harder double-digit range, there are steep sections capable of breaking rhythm.

How the gradient unfolds

The available profile data gives the full climb statistics rather than detailed sector-by-sector gradients, so the safest way to read Col de Roux is as a high-six-percent climb with sharper ramps folded into the effort. That distinction matters. A climb averaging 6.84% over 28 km is already demanding before the 11.64% maximum is considered. The steepest pitches are not the whole story, but they are where poor pacing becomes expensive.

The bottom should feel controlled, not easy. If it feels like threshold riding too soon, the length will turn that decision against you. On a climb this long, the gradient does not need to be extreme to accumulate fatigue. The combination of 28 km and 1918 m of net elevation gain rewards riders who keep pressure on the pedals without chasing every steeper moment.

Pacing and gearing notes

Ride this as an aerobic climbing test first and a strength test second. The average gradient is steep enough that sitting below your sustainable climbing effort is smarter than trying to bank time early. If you use /glossary/ftp as a pacing anchor, the opening should sit comfortably under the effort you would associate with a maximal long climb, because the decisive cost comes from holding form late.

Gearing should be chosen for the 11.64% maximum gradient, not just the 6.84% average. A setup that feels fine on the steady sections can become too heavy when the road kicks up, especially deep into a 28 km ascent. The goal is to preserve cadence options, avoid grinding early, and leave enough range to stay seated through the steeper ramps.

For riders targeting a steady ascent, the best approach is simple: cap the effort on the steepest gradients, resist over-responding to changes in pitch, and let consistency do the work. Col de Roux is hard because it is long, high, and persistent. The rider who treats it with that respect will usually climb faster than the rider who treats the average gradient as permission to start too hard.