Col de la Colle-Saint-Michel

Overview

The Col de la Colle-Saint-Michel is a Category 2 climb in France that earns its classification through sustained effort rather than relentless brutality. At 10.1 km long with an average gradient of 5.65%, it sits in the moderate range on paper — but the 21.99% maximum gradient tells a different story about what's hiding in the middle sections.

The climb begins at 857 m elevation and finishes at 1430 m, accumulating 1136 m of total ascent across those 10.1 km. That total ascent figure is notably high relative to the distance, which signals that the road wastes little time on flat or descending sections — you're climbing for most of the ride.

How the Gradient Unfolds

The 5.65% average is a useful planning baseline, but treat it as exactly that: an average. The gap between that figure and the 21.99% maximum indicates sharp gradient spikes hidden within otherwise manageable terrain. Expect sections that feel close to the average to be interrupted by ramps well into the double digits.

A few practical implications:

• Lower sections: Starting at 857 m, the early kilometres tend to be the most forgiving on climbs of this profile. Use them to find your rhythm and resist the urge to push hard.
• Mid-climb ramps: The maximum gradient of 21.99% is steep enough to stop underprepared gearing dead. These sections demand either a significant gear reduction or a deliberate power spike — neither of which is sustainable for long.
• Upper kilometres: With 1136 m of total ascent packed into 10.1 km, fatigue accumulates faster than the gradient alone would suggest. The final kilometres to 1430 m tend to expose any pacing mistakes made earlier.

Pacing Notes

For a Category 2 climb of this length, FTP-based pacing is the most reliable approach. Target a sustainable effort in the 75–85% FTP range for the bulk of the ascent, depending on your fitness and what else is on your ride or race agenda.

The 21.99% maximum gradient is the single biggest pacing trap on this climb. Riders who are already operating near threshold when they hit one of those ramps face a binary choice: blow up or soft-pedal. Neither is ideal. The better strategy is to arrive at the steepest sections with a small power reserve — slightly under your target effort on the approach — so you can absorb the ramp without going into the red.

If you're using a power meter, avoid anchoring to average gradient targets through the steep sections. Let power float naturally and focus on keeping cadence from dropping below a manageable floor. At 21.99%, even small cadence drops create disproportionate strain.

Gearing

Do not underestimate the 21.99% maximum gradient. For reference, anything above 20% will challenge a standard compact chainset (50/34) paired with an 11-28 cassette for most recreational and sportive riders. Consider:

• A 32 or 34-tooth cassette if your drivetrain supports it
• A sub-compact or 1x setup with a wide-range cassette
• Scouting where the steepest ramps fall so you can shift early rather than under load

Shifting under heavy load on steep gradients risks dropped chains and missed shifts — both costly on a ramp that demands continuous momentum.

Summary

The Col de la Colle-Saint-Michel is a climb that rewards honest pacing and punishes overconfidence in the early kilometres. Its 5.65% average is accessible; its 21.99% maximum is not. Build your effort around the hard sections, gear appropriately, and bank on the 1136 m of total ascent to test your patience as much as your fitness.

Use the FTP Estimator to anchor your power targets before attempting this climb.