Collet du Linge

What to Expect on Collet du Linge

Collet du Linge sits in the Vosges mountains of eastern France and earns its Category 2 rating honestly. The climb runs 14.5 km from bottom to summit, gains 952 m of total ascent, and averages 4.64% across its length — a figure that sounds manageable until the road decides otherwise.

The average gradient is kept in check by genuinely easier lower slopes, which means the upper half extracts a significant toll. That maximum gradient of 18.81% is not an anomaly you can ignore in your pacing plan; it is the climb announcing itself at its worst, and it arrives when your legs are already compromised.

How the Gradient Unfolds

The opening kilometers from the start elevation of 317 m are relatively forgiving. The road establishes a rhythm without immediately threatening your lactate threshold, which makes it tempting to push pace early. Resist that.

As the climb progresses toward the summit at 987 m, the gradient tightens and becomes less predictable. The average of 4.64% conceals sections that are genuinely shallow alongside sections that spike hard. When a climb's maximum gradient is more than four times its average — as it is here at 18.81% versus 4.64% — that disparity signals significant gradient variance. Expect multiple pitches well above the average before the summit.

Key Gradient Reference Points

• Average gradient: 4.64%
• Maximum gradient: 18.81%
• Total ascent: 952 m over 14.5 km
• Gradient ratio (max/avg): ~4x — expect pronounced spikes

Pacing Notes

The moderate average gradient encourages riders to treat this as a tempo effort, but the 18.81% maximum makes that a trap. If you arrive at the steepest pitches already above your FTP, the climb will shut you down quickly.

Recommended approach:

• Target 75–85% of FTP for the opening third. The road is manageable here; use it to settle breathing and heart rate.
• Expect to drop effort on the easier sections rather than banking time — conserve instead of accelerate.
• When the steep pitches hit, shift early and spin rather than grinding. Mashing a big gear at 18%+ on tired legs invites premature failure.
• Treat any section below 3% as active recovery, not an invitation to push.

If you want to baseline your sustainable power before attempting this climb, the FTP estimator will give you a working number to pace from.

Gearing

For most riders, a compact chainset (50/34) paired with an 11-32 or 11-34 cassette is appropriate. The 18.81% maximum gradient is steep enough that a 28-tooth sprocket at the rear may leave you out of options on the hardest ramps, particularly late in the climb when cumulative fatigue is a factor. Stronger riders on a standard chainset (52/36) should ensure they have at least a 30-tooth sprocket available.

Do not underestimate the 952 m of total ascent. Even at a moderate average gradient, nearly a full kilometer of vertical gain across 14.5 km is a genuine physiological load.

Summary

Collet du Linge rewards climbers who pace by effort rather than speed or distance. Its moderate average conceals sharp gradient spikes, and its Category 2 classification reflects cumulative demand rather than a single brutal wall. Ride the easy sections easy, shift before you need to on the steep pitches, and keep something in reserve for the upper road.