Col de Torrent

Overview

Col de Torrent is a short, severe HC climb in Switzerland. Over just 4.5 km it delivers a net elevation gain of 676 m, rising from a start elevation of 1644 m to a summit at 2320 m. At an average gradient of 15%, this is not a climb you settle into — the road tilts up hard from the base and stays there, and its HC category reflects the sustained punishment rather than any great length.

The gap between net gain and total work is where the real story sits. The net elevation gain is 676 m, but the total ascent is 799 m — a difference of 123 m. That 123 m of extra climbing comes from undulation: sections where the road dips or eases before pitching up again. On a climb this steep and this short, that mismatch means your legs pay for more vertical than the summit altitude alone suggests, and every recovery you get is immediately clawed back.

How the Gradient Unfolds

A 15% average on a 4.5 km climb is already extreme, but averages flatten the truth. The 123 m of undulation means the road is not a smooth ramp — it stacks steep pitches against brief lulls, and the steepest ramps sit well above the average. Expect the gradient to swing hard, forcing repeated surges rather than one settled tempo.

• Short flatter or slightly eased sections that read as recovery but barely let heart rate drop
• Repeated steep pitches stacked back to back, each demanding a fresh effort
• The steepest ramp well into double digits above the 15% average, where cadence collapses

Pacing Notes

On an even, uniform climb you can hold a steady wattage. Col de Torrent's undulation breaks that model. Chasing even speed here is a trap — you would blow apart on the steep ramps trying to hold a number. Instead, pace to even effort: hold your sustainable power output as your ceiling on the steep pitches, and accept that speed will vary wildly across the profile. On the brief eased sections, resist the urge to accelerate — soft-pedal and bank recovery for the next ramp. Know your number before you start; run the FTP estimator so you have a hard cap to ride against rather than guessing on the road.

Gearing

The steepest gradient governs your setup, and at 15% average the ramps demand serious range. Run a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 is the sensible floor here, and many riders will want more. Grinding a big gear on pitches this steep wrecks your legs and your knees. Check your setup before the ride: confirm the cassette, the derailleur capacity, and that the chain shifts cleanly into the largest sprocket under load. There is no room to discover you are under-geared halfway up.

Summary

• Length: 4.5 km
• Average gradient: 15%
• Net elevation gain: 676 m
• Total ascent: 799 m
• Category: HC

Col de Torrent is a specialist's climb: short enough to look manageable on paper, steep and undulating enough to punish anyone who paces it like a normal ascent. Respect the 15% average, gear low, ride to effort, and the summit at 2320 m is yours.