Daibosatsu pass

Overview

Daibosatsu Pass is a hors catégorie (HC) climb in Japan, one of the hardest categories a paved ascent can carry. It runs 7.6 km from a start elevation of 765 m to a summit of 1,894 m, delivering a net elevation gain of 1,129 m. Those numbers put it firmly in serious-climb territory: an HC rating on a sub-8 km road means the difficulty comes from raw steepness, not length.

The total ascent is 1,211 m against a net gain of 1,129 m — a difference of 82 m. That gap means the road is not a clean, monotonic drag upward; there are short descents or flat pitches that force you to reclimb ground you have already gained. For pacing and fuelling, treat this as extra hidden work: your legs and your data both have to account for climbing more than the net profile suggests.

How the Gradient Unfolds

The 14.95% average is punishing on its own, but averages smooth over the reality. With a maximum gradient of 36.06%, the steepest ramps are far harsher than the mean, and the 82 m of undulation means some of that average is diluted by easier ground — implying the hard pitches are harder still to compensate.

• Flatter or recovery sections where the road eases briefly, contributing to the undulation gap
• Repeated short climbs that force you to reaccelerate after every dip
• The steepest ramp near 36%, where cadence collapses and you fight to keep the wheels turning

Pacing Notes

On an undulating HC climb like this, chase even effort, not even speed. Your pace will swing wildly between the near-36% ramps and the flatter recovery pitches, and trying to hold a constant speed will spike your power into the red on every steep section. Anchor your effort to your sustainable power output and let velocity vary with the gradient.

If you do not know that ceiling, set it before you ride using the FTP estimator. On the steepest ramps you will unavoidably surge above threshold — accept those short overshoots, then use the recovery pitches to bring average power back into line rather than pressing on.

Gearing

With a maximum gradient of 36.06%, gearing is non-negotiable. A standard chainset will not turn on the steep ramps at any survivable cadence. Fit a compact or sub-compact chainset paired with a wide-range cassette — think 34×32 or 34×34 as a starting point, and go easier if you have it. Check your setup before the ride, not at the base of the climb: confirm the chain reaches the largest sprocket cleanly and the derailleur handles the range without rubbing.

Summary

• Length: 7.6 km
• Average gradient: 14.95%
• Maximum gradient: 36.06%
• Net elevation gain: 1,129 m
• Total ascent: 1,211 m
• Category: HC

Daibosatsu Pass is short, brutally steep, and unforgiving of poor gearing or pacing. Respect the undulation, protect your effort ceiling, and arrive with a cassette that matches the near-36% ramps.