Col du Marchairuz

Overview

Col du Marchairuz is a category 1 climb in Switzerland, rising through the Jura. It runs 11.4 km from a start elevation of 753 m to a summit at 1455 m, for a net elevation gain of 702 m. At an average gradient of 6.17%, it sits firmly in sustained-tempo territory: long enough to reward pacing discipline, steep enough that you cannot coast through it.

The number to watch is the gap between net gain and total ascent. You climb 702 m of net elevation, but you actually gain 926 m over the ride — 224 m of extra ascent hidden in dips and rollers. That undulation means the road gives back altitude and then takes it again, so your legs pay for more climbing than the summit-minus-start figure suggests. Plan your effort around the total ascent, not the net.

How the Gradient Unfolds

The 6.17% average is a blend, not a constant. With 224 m of extra climbing folded into the profile, the gradient swings above and below the mean repeatedly rather than holding steady. Expect the steepest ramp to reach 17.61% — a sharp pitch that demands you shift down early and stay seated where you can.

• Flatter or descending recovery sections where you regain rhythm and refuel
• Repeated short climbs that stack up into the 224 m of ascent beyond the net gain
• A steepest ramp around 17.61% that spikes well above the 6.17% average

Pacing Notes

On a smooth, even climb you can ride to a single number. Here the undulation makes even-speed pacing a trap: chasing a constant speed over the rollers spikes your power on every rise. Aim instead for even effort, holding a steady sustainable power output through the pitches and letting speed rise on the descents. Ease slightly before the 17.61% ramp so it does not blow your effort apart. If you do not know your ceiling, run the FTP estimator first and set your target from that, not from feel on the day.

Gearing

Gearing is governed by the steepest gradient, and 17.61% is steep enough to strand you in the wrong ratio. Run a compact (50/34) or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 low gear keeps your cadence up on the hardest ramp without grinding. Check your setup before the ride: confirm the cassette fits your derailleur and that you can actually reach the lowest sprocket under load. Discovering you are one gear short at 17.61% is a costly mistake.

Summary

• Length: 11.4 km
• Average gradient: 6.17%
• Maximum gradient: 17.61%
• Net elevation gain: 702 m
• Total ascent: 926 m
• Category: 1

Col du Marchairuz rewards riders who respect its rolling profile: pace to the 926 m of total ascent, gear for the 17.61% ramp, and hold an even effort across the 11.4 km rather than chasing speed over every rise.