Col de Sevan

Overview

Col de Sevan is a hors catégorie climb that leaves no room for bluffing. Over 16.7 km the road averages 9.01%, a figure that would be brutal on a short ramp and becomes genuinely serious when sustained across this distance. From a start elevation of 390 m the climb tops out at 1892 m, a net gain of 1502 m, while the total ascent measured along the road comes to 1472 m. That difference tells you the climb is not perfectly monotonic — there are pitches where the road briefly gives back a little before clawing it all back and more. With a maximum gradient of 22.43%, Sevan earns its HC label the hard way: through relentless steepness rather than sheer length alone.

How the Gradient Unfolds

A 9.01% average across 16.7 km is unusual because it is so high with so little relief. On most long climbs the mean is dragged down by flatter valleys or false flats; here the number stays punishing almost throughout. The gap between the 1502 m net gain and the 1472 m total ascent shows the road is not a single unbroken drag — expect short dips or plateaus that interrupt your rhythm, then reload the pressure. The 22.43% maximum is more than double the average, so somewhere on this climb there is a ramp steep enough to force you out of the saddle or straight into your easiest gear. Treat the average as your baseline suffering and the max as the spike you must survive without blowing apart.

Pacing Notes

On a climb this long and steep, pacing is everything. Anchor your effort to your FTP and aim to sit just below it for the sustained sections, leaving headroom for the ramps toward that 22.43% maximum where power will spike whether you like it or not. Because the climb gains 1502 m, small over-efforts compound: a few extra watts early can cost you minutes late. If you do not know your threshold, run the numbers through the FTP estimator before you commit to a target, then set a ceiling and refuse to cross it in the first third. Save your matches for the steepest pitches, not for chasing wheels on the shallower breaks.

Gearing

Do not under-gear this one. For a 16.7 km climb averaging 9.01% with pitches up to 22.43%, you want a compact crank paired with a wide-range cassette. A 34×32 is the sensible minimum for strong climbers who can hold a high cadence under load, but most riders will be far happier with a 34×34, which buys you enough spin to keep turning through the steepest ramps without grinding your knees or stalling. Given the total ascent of 1472 m, protecting your legs early with easier gearing pays dividends over the full hour-plus of climbing.

Summary

Col de Sevan is a pure HC effort: long, ferociously steep, and unforgiving of poor pacing. Respect the average, brace for the 22.43% spike, gear low, and ration your effort.

Length: 16.7 km
Average gradient: 9.01%
Max gradient: 22.43%
Start: 390 m
Summit: 1892 m
Net gain: 1502 m
Total ascent: 1472 m
Category: HC