Porters Pass

Overview

Porters Pass is a Category 3 climb in New Zealand, running 7.3 km from a start elevation of 552 m to a summit of 925 m. On paper it is a modest ascent: the net elevation gain is 373 m, and the average gradient across its length sits at 5.09%. Those figures describe a road that trends steadily upward without ever looking, on the profile, like a wall.

The road, however, does not simply climb. The total ascent is 608 m against a net gain of just 373 m — a 235 m gap. That difference means the road gives back roughly 235 m of hard-won height before the summit, forcing you to re-climb it. The consequence is that your legs do far more work than the net gain suggests, and the effort feels heavier than a clean 373 m climb of the same length would.

How the Gradient Unfolds

The 5.09% average is an accountant's number that hides the terrain. Because 235 m of the ascent is spent re-climbing lost ground, the real climbing sections are steeper than the average implies, and they are broken up by descents and flats that pull the average down.

• Flatter and descending sections where the road gives back height — these lower the average but offer only partial recovery at speed
• Repeated short climbs stacked back-to-back, each demanding a fresh surge of effort
• The steepest ramp, well above 5.09%, where you carry the most load and where a mistimed gear costs you

Pacing Notes

On a smooth climb you can hold an even effort and let speed vary. On an undulating road like this one, that discipline matters more. Anchor your ride to a target sustainable power output rather than a target speed, and hold that power through the steep pitches without spiking. Do not chase your climbing pace across the flats and descents — soft-pedal or recover there, then reapply steady effort on the next ramp. If you do not know your ceiling, run the FTP estimator beforehand so your target power is grounded in real numbers, not guesswork.

Gearing

The steepest ramp on this climb is the number that should govern your setup, not the 5.09% average. Fit a compact (34-tooth inner) or sub-compact chainset and pair it with a wide-range cassette — a 34×32 or 34×34 gives you a bailout gear that lets you spin the steep pitch instead of grinding it. Check your chainset and cassette before the ride; the repeated short climbs punish anyone who arrives over-geared.

Summary

• Length: 7.3 km
• Average gradient: 5.09%
• Net elevation gain: 373 m
• Total ascent: 608 m
• Category: 3

Porters Pass rewards riders who respect the gap between its net gain and its total ascent. Pace to power, gear for the steepest ramp, and treat the descents as recovery — not rest — and the climb will play to its true 608 m of work.