Ōdaira Pass

Overview

Ōdaira Pass is a Category 1 road climb in Japan, running 9.2 km from a start elevation of 694 m to a summit at 1374 m. That places the net elevation gain at 680 m, giving an average gradient of 7.37% across its length. On paper it reads as a steady, sustained effort — a long grind at a consistent pitch.

The profile tells a different story. The total ascent is 991 m, well above the 680 m of net gain, meaning the road climbs 991 m while only ending 680 m higher than it started. That 311 m gap is dropped and re-climbed along the way. Every metre of descent inside the climb is a metre you pay back at gradient, so the real effort is heavier than the net figure suggests. Treat this as a climb that fights you the whole way up, not a smooth escalator.

How the Gradient Unfolds

The 7.37% average is a blend, not a description of any single section. With 311 m of hidden re-climbing packed into 9.2 km, the pitches that matter sit well above average, and they are separated by softer terrain that lets your legs reset before the next wall.

• Flatter recovery sections and short descents where the road gives back elevation you will have to earn again
• Repeated short climbs that punch above the 7.37% average, stacked through the middle of the profile
• A steepest ramp far harder than the average — the kind of pitch that forces you out of the saddle if your gearing is short

Pacing Notes

On an undulating climb like Ōdaira Pass, chase even effort, not even speed. Your pace will swing wildly between the recovery dips and the steep ramps, and that is correct — trying to hold a constant speed would spike your power on every rise and drain you before the summit. Anchor the ride to your sustainable power output and hold that band through the pitches, letting speed fall on the ramps and rise on the flats. If you do not know your ceiling, run the FTP estimator before you go, then ride the steep sections just under threshold so the repeated efforts do not compound into a blow-up.

Gearing

The steepest ramps here are severe enough that gearing is not optional. Fit a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 at minimum, and 34×34 if you have it, to keep a spinnable cadence on the sharpest pitches without grinding. The undulation makes this worse: you hit the walls repeatedly with tired legs. Check your chainset and cassette before the ride, not at the base of the climb.

Summary

• Length: 9.2 km
• Average gradient: 7.37%
• Net elevation gain: 680 m
• Total ascent: 991 m
• Category: 1

Ōdaira Pass rewards riders who respect the gap between net gain and total ascent. Pace by effort, gear low, and treat the 991 m of climbing — not the 680 m net — as the number that defines your day.