Kasagi Pass

Overview

Kasagi Pass is a category 3 climb in Japan running 8.2 km from near sea level to its summit. It starts at 6 m and tops out at 388 m, for a net elevation gain of 382 m. On paper that reads as a modest, moderate-length climb, and the numbers alone suggest a steady grind rather than anything dramatic.

The paper version and the real version diverge, though. While the net gain is 382 m, the total ascent is 621 m. That 239 m difference is climbing you do twice — you gain it, give it back on descents or false flats, and gain it again. The climb undulates rather than rising cleanly, so your legs absorb roughly 60 percent more vertical work than the net figure implies. Budget effort against 621 m, not 382 m.

How the Gradient Unfolds

The average gradient of 4.63 percent is an honest number for the whole ascent but a misleading one for any single moment on it. On an undulating profile like this, the average is a blend of downhill and flat sections against much steeper ramps — you will rarely be riding at 4.63 percent. The maximum pitch hits 36.29 percent, a wall that demands you are already in your lowest gear before you reach it.

• Flatter and recovery sections where you can spin, drink, and reset before the next rise
• Repeated short climbs stacked back to back, which is where the extra 239 m of total ascent comes from
• One savagely steep ramp at up to 36.29 percent that dictates your entire gearing choice

Pacing Notes

On a smooth climb you can chase even-speed pacing. Here, don't. The undulation makes even-speed pacing a trap — holding constant speed over the steep ramps forces surges well above your sustainable power output, and those matches burn out your legs for the climbs that follow. Pace to even effort instead: let your speed drop on the ramps, keep power near threshold, and use the flatter sections and descents to recover rather than to attack. Know your number before you start; the FTP estimator gives you the ceiling to hold your steeper pitches under.

Gearing

The 36.29 percent maximum pitch governs your setup entirely. Bring a compact or sub-compact chainset paired with a wide-range cassette — think 34×32 or 34×34 as a floor, and go easier if your legs or loaded bike ask for it. A gear that feels fine on the 4.63 percent average will stall you dead on the wall. Check your chainset and cassette before you ride, not at the bottom of the ramp.

Summary

• Length: 8.2 km
• Average gradient: 4.63%
• Maximum gradient: 36.29%
• Net elevation gain: 382 m
• Total ascent: 621 m
• Category: 3

Kasagi Pass rewards riders who read past the average. Pace to effort, gear for the steepest ramp, and treat the 621 m of total ascent as your true workload.