Jikkoku Pass

Overview

Jikkoku Pass is a Hors Catégorie (HC) climb in Japan that packs serious vertical into a short distance. Over 7.3 km it delivers 965 m of net elevation gain, rising from a start elevation of 421 m to a summit at 1,386 m. That works out to an average gradient of 13.27%, a figure that puts it firmly among the hardest paved climbs you can ride. There is nowhere to hide on a road this steep for this long.

The average alone understates the difficulty. Against 965 m of net gain, the climb records 1,260 m of total ascent — a 295 m gap. That difference means the road does not climb cleanly; it dips and rises repeatedly, forcing you to re-accelerate up fresh ramps after every descent. Every metre you give back on a downhill is a metre you have to earn again, and those re-starts are where the real fatigue accumulates.

How the Gradient Unfolds

A 13.27% average is already brutal, but it is a blend of terrain that ranges from brief recovery to walls that push toward the maximum recorded gradient of 36.68%. Expect the pitch under your wheels to swing hard rather than settle. The undulation baked into the total ascent means you will crest a rise, drop briefly, then face another steep kick almost immediately.

• Short flatter or descending sections that offer only seconds of recovery before the next ramp
• Repeated punchy climbs stacked back-to-back, thanks to the 295 m of undulation
• At least one savage ramp approaching the 36.68% maximum, where traction and balance matter as much as power

Pacing Notes

On a clean, steady climb you would ride to a fixed power target. Jikkoku Pass punishes that approach. The undulation means even-effort pacing beats even-speed pacing: hold your sustainable power output as the anchor and let your speed rise and fall with the gradient. Do not chase a constant pace up the steep ramps — you will overshoot threshold and pay for it on the next kick.

The trap here is the re-accelerations off each short descent. Resist stamping on the pedals to regain lost speed; ease back onto power instead. If you have not benchmarked your ceiling recently, run the FTP estimator first and set a conservative cap you can defend across all 7.3 km.

Gearing

The 36.68% maximum gradient dictates your setup, not the average. You want a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 as a minimum, and 34×34 if your derailleur allows it. On the steepest ramps, cadence collapses fast, and running out of gears here means grinding at unsustainable torque or stalling entirely. Check your chainset and cassette combination before the ride, and confirm the rear derailleur clears your largest sprocket.

Summary

• Length: 7.3 km
• Average gradient: 13.27%
• Maximum gradient: 36.68%
• Net elevation gain: 965 m
• Total ascent: 1,260 m
• Category: HC

Jikkoku Pass is a short climb that rides like a long one. The steep average, the extreme maximum ramp, and the 295 m of undulation baked into the total ascent combine into an effort that rewards restraint and low gearing over ambition. Pace it by feel and power, gear it for the worst pitch, and it becomes a climb you finish rather than one that finishes you.