Col de Porte (Jura)

Overview

Col de Porte (Jura) is an HC climb in Switzerland, rising out of the Jura terrain over 12.7 km. It starts at 527 m and tops out at 1,554 m, for a net elevation gain of 1,027 m at an average gradient of 8.07%. That average alone puts it firmly in serious-ascent territory: a sustained, hour-plus effort for most riders, with no soft-pedal introduction to ease into.

The climb's total ascent is 1,297 m against that 1,027 m of net gain — a 270 m difference. That gap is undulation: sections that drop or flatten and then force you to re-climb what you just gave back. On paper you gain 1,027 m; in your legs you pay for 1,297 m. Budget your effort against the total ascent, not the net figure, or you will arrive at the summit having spent more than you planned.

How the Gradient Unfolds

The 8.07% average is a blend, not a constant. The 270 m of extra ascent tells you the road repeatedly gives back altitude, which means the pitches that remain must be steeper than the average to compensate. Expect sharp ramps stacked against flatter connectors.

• Flatter or recovery sections where the road eases and even descends briefly — do not over-invest here, but keep momentum.
• Repeated short climbs that follow those dips, each one re-taking lost elevation.
• The steepest ramp well above the average — plan to spin, not grind, when it arrives.

Pacing Notes

On a smooth climb you would ride even-effort and let speed vary. Here, the undulation makes that harder: dips tempt you to coast and ramps tempt you to surge. Anchor to your sustainable power output rather than to speed or feel. Hold a steady target through the ramps, ease slightly on the recovery sections without stopping the effort entirely, and resist chasing a constant velocity — that only spikes your power on the steep bits. If you do not know your threshold, run the FTP estimator before you go so your target number is honest.

Gearing

The steep ramps on this climb govern your setup, not the average. Fit a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you the low end to keep cadence up when the road kicks. Grinding a big gear on an HC climb with 1,297 m of total ascent will cook your legs long before the summit. Check your chainset and cassette before the ride; the day of is too late to find you are one sprocket short.

Summary

• Length: 12.7 km
• Average gradient: 8.07%
• Net elevation gain: 1,027 m
• Total ascent: 1,297 m
• Category: HC

Col de Porte (Jura) is a full HC test: 12.7 km, 8.07% average, and 270 m of hidden re-climbing on top of a 1,027 m net gain. Pace to your power, gear for the steep ramps, and respect the total ascent — do that, and the summit at 1,554 m is well within reach.