Col du Mont Crosin

Overview

Col du Mont Crosin is a category 2 climb in Switzerland, running 8.3 km from a base at 678 m to a summit at 1171 m. That gives it a net elevation gain of 493 m across the ascent, with an average gradient of 5.91%. On paper it reads as a steady, mid-length climb — the kind of effort you can settle into rather than survive.

The number that changes that picture is total ascent. While the net gain is 493 m, the total ascent is 624 m — a 131 m difference. That gap tells you the road does not climb cleanly. There are stretches where you give back altitude before earning it again, meaning you re-climb the same 131 m spread across the profile. For your legs, the climb is longer and choppier than the net figure suggests, and the average gradient understates the real cost.

How the Gradient Unfolds

An average of 5.91% is a fiction of arithmetic here. With 131 m of undulation baked in, the flatter and downhill sections drag the average down, which means the climbing sections must be steeper than 5.91% to compensate. The headline number is the max gradient: 27%. That is a wall, not a slope, and it sits well above anything the average prepares you for.

Expect the profile to break down roughly like this:

• Flatter or recovery sections where the road eases or dips, letting your heart rate settle
• Repeated short climbs stacked back to back, each one re-gaining altitude you just lost
• A single steepest ramp at 27% that demands you are already in your easiest gear before you reach it

Pacing Notes

On a climb this undulating, chasing an even speed will wreck you. Holding the same pace over a 27% ramp as over a flat section means spiking your power far past threshold on every rise. Pace by even effort instead: hold a steady sustainable power output and let your speed rise on the shallow bits and fall on the steep ones. Accept that the recovery dips are where you bank matches, not where you attack.

Know your ceiling before you start. Run the numbers through the FTP estimator so you can set a wattage cap and refuse to exceed it on the ramps, no matter how short they look.

Gearing

The 27% maximum dictates your setup, full stop. A standard chainset will leave you grinding or walking. Fit a compact or sub-compact chainset paired with a wide-range cassette — think 34×32 or 34×34 — so you keep a spinnable cadence when the road stands up. Check your chainset and cassette before the ride, not at the base. A gear you don't have is one you can't shift into.

Summary

• Length: 8.3 km
• Average gradient: 5.91%
• Maximum gradient: 27%
• Net elevation gain: 493 m
• Total ascent: 624 m
• Category: 2

Col du Mont Crosin rewards riders who respect the undulation. Pace by effort, gear for the 27% ramp, and treat the 131 m of hidden re-climbing as the real work — the average gradient will lie to you the whole way up.