coll Mitjà

Overview

Coll Mitjà is an HC climb in France, the top rung on the categorization ladder and a serious undertaking for any rider. It runs 9.9 km from a start elevation of 1,011 m to a summit at 2,346 m, delivering a net elevation gain of 1,335 m. That is a punishing amount of vertical for under ten kilometers, and the HC label is earned rather than decorative.

The number that reshapes everything is total ascent. While the net gain is 1,335 m, the road actually climbs 1,922 m across its length. That 587 m gap is undulation: descents and dips that you have to reclaim later. Every meter you give back on a downhill is a meter you pay for again, so the true climbing workload is closer to 1,922 m than the net figure suggests. Plan your effort around the larger number.

How the Gradient Unfolds

The 13.55% average is a blended figure that hides both easier stretches and brutal ramps. On a climb with this much undulation, the average is almost meaningless as a moment-to-moment guide — you will rarely sit at exactly 13.55%. Expect long stretches well above it, punctuated by descents that drag the mean down.

• Recovery dips and short descents that give back elevation, accounting for the 587 m gap between net gain and total ascent
• Repeated short climbs where you re-earn the elevation you just lost, each one resetting your legs
• Sustained double-digit sections that push well past the average
• A steepest ramp that spikes far above 13.55% — respect it and leave a gear in reserve

Pacing Notes

Forget even-speed pacing here. The undulation makes speed a terrible proxy for effort: you will crawl on the ramps and roll faster through the dips regardless of how hard you push. Chase even effort instead, holding a steady sustainable power output and letting your speed rise and fall with the terrain.

The trap is overcooking the descents and dips to "save time," then blowing up on the next wall. Ride the flatter sections as genuine recovery, then meter the steep pitches carefully. If you do not know your numbers, run the FTP estimator before you go so you have a ceiling to pace against rather than guessing on the road.

Gearing

Gearing is dictated by the steepest pitches, and on Coll Mitjà those pitches are severe. A standard road setup will leave you grinding or walking. Fit a compact (50/34) or, better, a sub-compact chainset paired with a wide-range cassette — think 34×32 as a minimum, and 34×34 if your derailleur allows it. On a climb this steep and this long, an extra low gear is the difference between spinning and stalling.

Check your setup before the ride. Confirm the cassette range, verify the rear derailleur can handle it, and make sure your chain length is correct. Discovering you are undergeared at kilometer six is not a mistake you can fix on the mountain.

Summary

• Length: 9.9 km
• Average gradient: 13.55%
• Net elevation gain: 1,335 m
• Total ascent: 1,922 m
• Category: HC

Coll Mitjà is a short-distance, high-consequence HC climb where the undulation, not the average gradient, defines the effort. Pace by power, gear low, and treat the 1,922 m of total ascent as the real workload.