Shimizu Pass

Overview

Shimizu Pass is a category HC climb in Japan, the hardest classification we assign. It runs 8.5 km from a start elevation of 548 m to a summit at 1,443 m, delivering a net elevation gain of 895 m across its length. At an average gradient of 10.53%, this is a sustained, serious effort with no easy way to soften it.

The number that reframes the whole climb is the gap between net gain and total ascent. You climb 895 m net, but the road actually forces 1,376 m of total ascent on you — a difference of 481 m of descent scattered through the route. That undulation means the climbing is front-loaded and back-loaded onto pitches steeper than the 10.53% average suggests, and every metre you give back on a downhill has to be reclaimed higher up. Budget your legs for far more vertical work than the net figure implies.

How the Gradient Unfolds

An average of 10.53% is already brutal, but averages lie on a road with 481 m of hidden descent. Every downhill section drags the mean down, which means the climbing pitches must be considerably steeper than 10.53% to compensate. Expect the road to bite hardest where it recovers the elevation lost on the descents.

• Short recovery or descending sections that briefly drop you before the next wall
• Repeated ramps that repeatedly rebuild lost elevation
• The steepest pitches sitting well above the 10.53% average, where compensation for the descents is concentrated

Pacing Notes

On a smooth climb, even-effort and even-speed pacing nearly converge. On Shimizu Pass they diverge hard because of the undulation. Chase even speed and you will spike your sustainable power output on every steep ramp, then coast the descents — a recipe for blowing up. Instead, pace by even effort: hold a steady power band, let your speed rise on the shallower and descending sections, and accept slower speed on the walls without surging. Know your ceiling before you start; the FTP estimator gives you the number to hold against.

Gearing

With sustained double-digit gradients and steep compensating ramps, gearing is not optional insurance — it is the difference between spinning and grinding to a stop. Run a compact or sub-compact chainset paired with a wide-range cassette, something in the region of 34×32 or 34×34, so you keep a usable cadence on the steepest pitches. Check your setup before the ride. Discovering you are over-geared on a 10%-plus wall is a mistake you make only once.

Summary

• Length: 8.5 km
• Average gradient: 10.53%
• Net elevation gain: 895 m
• Total ascent: 1,376 m
• Category: HC

Shimizu Pass rewards riders who respect the numbers behind the average. Pace by effort, gear low, and treat the 1,376 m of total ascent — not the 895 m net — as the real measure of the day.