Bunkui-tōge Pass

Overview

Bunkui-tōge Pass is a Category 1 climb in Japan, running 5.9 km from base to summit. It gains 615 m net over that distance, starting at 832 m and topping out at 1,447 m. At a 10.44% average gradient across the full length, this is a sustained, high-effort ascent with no gentle opening to ease into.

The net gain of 615 m sits well below the total ascent of 802 m. That 187 m gap is the undulation: the road doesn't climb cleanly to the top but sheds and reclaims elevation along the way. In practice you're doing more vertical work than the summit-minus-base figure suggests, and every metre lost to a downhill has to be paid back on the next ramp. Budget your effort for 802 m of climbing, not 615.

How the Gradient Unfolds

The 10.44% average is already steep, but averages flatten out the story. With 187 m of hidden re-climbing and a maximum pitch of 24.51%, the gradient swings hard around that mean. Expect stretches well above 10.44% to offset the descents that pull the average down.

• Short recovery or downhill sections where the road gives back elevation before climbing again
• Repeated punchy ramps that reclaim that lost height, each one steeper than the average
• A steepest pitch of 24.51% that demands your lowest gear and full attention

Pacing Notes

On a clean, steady climb you can hold an even-effort or even-speed line and let the two roughly converge. This climb's undulation breaks that. Chasing even speed means overcooking the 24.51% ramps and stalling on the descents. Instead, hold a steady sustainable power output and let your speed rise and fall with the terrain — spin faster on the brief downhills, absorb the steep ramps without spiking your effort into the red. Know your ceiling before you start; use the FTP estimator to set a target you can carry across the full 5.9 km rather than one that empties you on the first steep pitch.

Gearing

The 24.51% maximum governs your setup, not the 10.44% average. A ramp that steep will grind a standard compact to a halt. Run a compact (34-tooth inner) or sub-compact chainset paired with a wide-range cassette — a 34×32 gives you room, and a 34×34 gives you margin on the worst pitches. Confirm your chainset and cassette combination before the ride; the base of a 24.51% wall is not where you want to discover your smallest gear is too tall.

Summary

• Length: 5.9 km
• Average gradient: 10.44%
• Maximum gradient: 24.51%
• Net elevation gain: 615 m
• Total ascent: 802 m
• Category: 1

Bunkui-tōge Pass packs a Category 1 effort into 5.9 km, and its undulation makes it harder than the net gain implies. Pace to your power, gear for the 24.51% pitches, and respect the 802 m you'll actually climb.