Mugikusa Pass

Overview

Mugikusa Pass is a Category 1 climb in Japan, running 12.4 km from a start elevation of 1,388 m to a summit at 2,121 m. Over that distance it delivers a net elevation gain of 733 m, placing it among the high-altitude ascents where thinner air compounds the physical demand of the gradient itself.

Look closer and the effort is larger than the net figure implies. Against 733 m of net gain, the climb records 1,058 m of total ascent. That 325 m difference is elevation you have to re-climb after giving it back on descents and false flats. In practical terms, the road does not rise cleanly: you pay for the same metres twice in places, so plan your energy around the total ascent, not the tidy net number.

How the Gradient Unfolds

The 5.91% average is a blend, not a constant. With a maximum gradient of 21.44%, the climb clearly stacks its work into short, sharp ramps that sit well above the mean, offset by flatter and descending sections that pull the average down. Riding to the average alone will leave you undergeared and over the limit on the steep pitches.

Expect the profile to break down roughly like this:

• Flatter and recovery sections where the road eases or briefly descends, giving back some of that 325 m of undulation
• Repeated short climbs that force you to re-accelerate rather than settle into one rhythm
• The steepest ramp near 21%, where cadence collapses and gearing decides whether you spin or grind

Pacing Notes

On a smooth climb you can hold even effort and let speed drift. Mugikusa's undulation makes that harder. Because sections descend and re-climb, chasing even speed would spike your power on every ramp and waste matches. Instead, anchor your pacing to a target sustainable power output and hold it through the steep pitches, letting speed fall where it must. Ease slightly on the flatter and downhill sections rather than surging to keep the clock moving. If you do not know your ceiling, run the FTP estimator first so your target on the ramps is grounded rather than guessed.

Gearing

The 21.44% maximum gradient governs your setup. At that pitch, at altitude, standard road gearing will leave you mashing at low cadence and burning your legs. Fit a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you a bailout ratio for the steepest ramp while keeping usable steps on the shallower gradients. Check your chainset and cassette before the ride, not at the trailhead.

Summary

• Length: 12.4 km
• Average gradient: 5.91%
• Maximum gradient: 21.44%
• Net elevation gain: 733 m
• Total ascent: 1,058 m
• Category: 1

Mugikusa Pass is a high, undulating Category 1 climb where the 1,058 m of total ascent and the 21.44% ramp matter more than the modest average. Pace to power, gear for the steep, and respect the extra 325 m the profile hides.