Col de Restefond

What to Expect on the Col de Restefond

Col de Restefond sits in the Haut Category — the hardest classification in road cycling — and it earns that designation without argument. Starting at 1,798 m, the road climbs to a summit at 2,673 m, delivering 875 m of net elevation gain across 9.3 km. The total ascent recorded is 1,361 m, which tells you this isn't a clean, linear grind: there are undulations and short false flats that lull you into spending energy you'll desperately need later.

The average gradient of 9.39% is already at the upper limit of what most riders can sustain for extended efforts without careful power management. What makes Restefond genuinely dangerous is the recorded maximum gradient of 57.3% — an extreme ramp that will appear without mercy if you stray off the main line or encounter a particularly vicious pitch. Even if that figure represents a momentary spike on a hairpin or a short wall, at altitude and mid-climb it is categorically ride-ending if you're not prepared.

How the Gradient Unfolds

With a start elevation already above 1,798 m, your body is operating in thinner air before the climb even begins. Oxygen availability is reduced, lactate accumulates faster, and perceived effort climbs faster than the numbers on your head unit suggest.

Given the 9.3 km length and the gap between average (9.39%) and maximum (57.3%) gradient, expect the profile to include:

• Sustained double-digit pitches that push well above the average for extended stretches
• Brief recoveries on flatter or slightly downhill sections — these account for the difference between 1,361 m total ascent and 875 m net gain, so use them actively: soft-pedal, recover breathing, don't accelerate
• Sharp gradient spikes that can exceed anything your legs have encountered on more famous climbs

Pacing Notes

This climb rewards conservative early pacing more than almost any other HC ascent. A rider going out at threshold on the lower slopes will be in serious trouble by the midpoint.

Recommended approach:

• Target 85–90% of your functional threshold power for the opening third. If you don't know your FTP, use the FTP estimator before attempting this climb.
• When a flatter section appears, resist the urge to push — use it to bring heart rate and breathing back under control.
• On gradient spikes, shift to the easiest available gear immediately. Grinding a big gear through a steep wall at altitude is the fastest route to a blown-up effort.
• Cadence: aim to keep it above 70 rpm even on the steepest sections. A low-cadence, high-torque approach at altitude accelerates muscular fatigue.

Gearing Recommendations

Do not underestimate this climb based on its 9.3 km length. The combination of high starting elevation, a near-10% average, and documented extreme gradient spikes means you need a bailout gear.

• Road compact (34t) with an 11-32 or 11-34 cassette is the sensible minimum for most riders.
• Riders comfortable at sustained high gradients on climbs like Alpe d'Huez should still consider a wider cassette range here, given the altitude penalty.
• If you're running a 1x drivetrain, a 40t chainring with a 10-51 cassette is worth considering.

The Bottom Line

Col de Restefond is not a climb to take on as a casual day out. The HC category, the 9.39% average gradient, the altitude, and the extreme gradient spikes make it one of the most demanding ascents in the French Alps. Ride it with a proper pacing strategy, the right gearing, and full respect for what the numbers are telling you.