col de la Chamboite

Overview

Col de la Chamboite is a Category 2 climb in France, running 16.5 km from a valley floor at 690 m to a summit of 1487 m. That gives a net elevation gain of 797 m, and on paper an average gradient of 4.83%. It is a long, sustained effort rather than an explosive one, the kind of climb where consistency matters more than a single hard surge.

But the net figure understates the work. Total ascent over the climb is 1246 m, which is 449 m more than the net gain implies. That difference is undulation: the road repeatedly climbs, levels, and dips back before climbing again. You do not just gain 797 m of altitude, you actually pedal uphill for close to 1246 m worth of ascent. Expect the effort to feel harder than a 4.83% average suggests.

How the Gradient Unfolds

The 4.83% average is a blend, not a description of the road under your wheels. With a maximum pitch of 15.44%, the steep sections sit far above the mean, and the flatter, rolling stretches drag the average down.

• Recovery zones: false flats and short descents where the gradient eases well below average
• Repeated short climbs: punchy rises that stack up to the 1246 m total ascent
• The steepest ramp: a pitch touching 15.44%, roughly three times the average, where the climb bites hardest

Pacing Notes

On an undulating climb like this, chasing an even speed is a trap. Holding constant km/h forces you to spike your power on every rise and coast on every dip, burning matches unnecessarily. Instead, pace by even effort. Keep your output anchored near your sustainable power output, letting speed rise on the flatter sections and fall on the ramps toward 15.44%.

The 449 m of hidden climbing means those ramps arrive often, so leave headroom. If you are unsure where your ceiling sits, run the FTP estimator before you commit to a number for the day.

Gearing

The 15.44% maximum is what should govern your gearing, not the 4.83% average. On a 16.5 km climb with repeated steep pitches, you want a compact or sub-compact chainset paired with a wide-range cassette. A 34×32 will cover most riders, and a 34×34 gives extra margin for tired legs late in the 1246 m of total ascent. Check your setup before the ride, not at the base of the first ramp.

Summary

• Length: 16.5 km
• Average gradient: 4.83%
• Maximum gradient: 15.44%
• Net elevation gain: 797 m
• Total ascent: 1246 m
• Category: 2

Col de la Chamboite rewards riders who respect its rolling profile. Pace by effort, gear for the steepest ramp, and treat the 449 m of extra ascent as the real story behind a deceptively gentle average.