Lewis Pass

Overview

Lewis Pass is a Category 3 road climb in New Zealand, ascending 291 m net over 6.6 km at a 4.38% average gradient. Those numbers suggest a manageable effort — and for the most part, the climb is steady rather than savage — but a maximum gradient of 25.82% signals at least one section that will punish anyone who arrives at it under-geared or over-paced.

Total ascent across the climb reaches 711 m, which is considerably more than the 291 m net gain. That gap between net and total ascent tells you the road isn't a clean, unbroken ramp. Expect undulations, brief false flats, and at least one sharp ramp that accounts for the peak gradient figure.

How the Gradient Unfolds

With an average of 4.38% over 6.6 km, the bulk of Lewis Pass sits in the moderate range — the kind of gradient where a controlled tempo effort is entirely achievable if you resist the temptation to respond to short steeper pitches. Think of the average gradient as your baseline; anything significantly above it is a temporary cost you need to budget for.

The 25.82% maximum is the outlier. A ramp of that steepness — even if it lasts only a few dozen metres — demands either a significant gear change or a sharp spike in power output. If you're already fatigued when you hit it, neither option feels clean. Identifying where this ramp sits before you ride is worth the preparation time.

Key gradient zones to anticipate:

• Lower slopes: Likely close to or below average gradient — use this section to establish rhythm and avoid burning matches early.
• Mid-climb undulations: The difference between net and total ascent (291 m vs 711 m) points to terrain that rises and dips. Don't fully recover on descending sections by freewheeling; keep the legs turning.
• Maximum ramp (25.82%): Treat this as a micro-climb within the climb. Shift early, reduce cadence if needed, and keep upper body relaxed.

Pacing Notes

For most riders, Lewis Pass suits a FTP-based approach. Target a sustainable percentage of your threshold power from the base and hold it through the variable terrain. Spiking effort on the steeper pitches then trying to recover on flatter sections leads to accumulated fatigue that compounds on the back half.

If you're unsure of your current threshold figures, run through the FTP estimator before setting targets for this climb.

The relatively modest net elevation gain of 291 m means the overall energy cost is not extreme — but the 711 m of total ascent and the near-26% maximum gradient mean careless pacing will still hurt you.

Gearing Recommendations

For a maximum gradient of 25.82%, a compact chainset (50/34) paired with an 11-32 or 11-34 cassette gives most riders sufficient range to turn a manageable cadence on the steepest section without grinding to a near-halt. Riders on a standard 53/39 setup should be confident in their ability to produce force at low cadence, or should fit a wider cassette before attempting the maximum ramp.

Electric shifting helps here — the ability to make fast, precise changes under load matters when a steep ramp arrives without warning.

Summary

Lewis Pass is approachable as a Category 3 climb, but the gap between its average and maximum gradients demands respect. Ride the moderate sections conservatively, anticipate the sharp ramp, and carry appropriate gearing. The total ascent figure is a useful reminder that the road gives nothing back for free.