Col des Prés

Overview

Col des Prés sits in the French Alps and carries a Category 3 rating, but that classification can lull you into complacency. The headline numbers — 13.5 km at an average gradient of 3.61% — paint a picture of a gentle, rolling ascent. The fine print, specifically a maximum gradient of 44.51%, tells a very different story for at least one section of road.

Total ascent over the 13.5 km is 1,114 m, starting from 661 m and topping out at 1,149 m at the summit. The math on those figures alone reveals how uneven the terrain must be: a climb that averages under 4% yet accumulates over 1,100 m of vertical has to include descents or flat recoveries between steeper ramps — and at least one ramp that is genuinely extreme.

Gradient Profile

The 3.61% average is close to meaningless here as a pacing guide. With a max gradient of 44.51%, the climb almost certainly includes:

• Extended flat or near-flat sections that drag the average down
• One or more steep ramps, with at least one reaching the near-limit of what a road bike can physically ascend
• Possible short descents that mask the cumulative vertical effort

A 44.51% gradient is not a typo. For reference, most dedicated cycling climbs peak in the 20–25% range; anything above 30% borders on unrideable for the majority of riders on standard gearing. Treat this figure as a serious warning: there is at least one section on Col des Prés that may require dismounting unless you arrive with a compact chainset and a wide-range cassette.

Pacing Notes

Because the average gradient is low, the temptation is to push harder on the flatter stretches to bank time and effort. Resist that. The unknown location of the extreme ramp within the 13.5 km means you should treat every moderate section as a recovery opportunity rather than an invitation to press.

• Ride conservatively on the flats. Keep your effort at or below your functional threshold power on any section that feels easy. You will need reserves.
• Identify the steep section early. If you have a GPS device loaded with gradient data, watch for where the road kicks. The shift from moderate to extreme will be abrupt.
• Do not attack the ramp. On gradients above 30%, momentum is almost irrelevant. Slow, controlled pedaling in the lowest gear you have is the only viable strategy.
• Use the FTP estimator before planning power targets. The variable profile makes average-power pacing unreliable; work from a solid FTP baseline and adjust in real time.

Gearing Recommendations

Standard compact gearing (50/34 front, 11-28 rear) is likely inadequate for the steepest section. Strongly consider:

• A 34/32 or 34/34 low gear combination
• A 1x drivetrain with a 10-42 or 10-46 cassette if your setup allows
• Confirming your bike's derailleur capacity before attempting the climb

If you are not sure your current gearing can handle gradients in the 30–44% range, it is worth checking a comparable profile on the climbs directory to benchmark what extreme gradients demand.

Summary

Col des Prés is deceptively categorized. The Category 3 tag and 3.61% average suggest a manageable day out; the 44.51% maximum gradient demands the same preparation you would bring to a far more severe climb. Ride the easy sections easy, bring the lowest gearing available, and locate that ramp before you hit it at the wrong cadence.