Changla Pass

Overview

Changla Pass is an hors catégorie monster, and the numbers make no apology for it. Over 40.4 km the road lifts you from a start elevation of 3315 m to a summit of 5360 m, a net gain of 2045 m. The average gradient sits at 5.07%, which on paper sounds humane — but that figure is stretched thin across a distance most riders never sustain in a single climb. At its steepest the road pitches to 14.29%, and the total ascent of 2035 m confirms this is almost entirely one long upward march with barely a metre given back.

The defining feature here is not any single ramp but the sheer length combined with thin air. You begin already above 3315 m and finish more than 2000 m higher, so altitude — not just gradient — is the adversary.

How the Gradient Unfolds

Read the shape from the math. With 2035 m of total ascent against 2045 m of net gain, this climb almost never descends; the ten-metre gap between the two figures tells you the profile is monotonic. That is unusual and unforgiving — there are no rolling recoveries to reset your legs.

The 5.07% average masks real variation. A max of 14.29% means individual sections run to nearly three times the mean, so expect long stretches gentler than 5% punctuated by sharp pitches that spike toward 14.29%. Across 40.4 km, the arithmetic leaves plenty of moderate gradient, but every steep kick lands with less oxygen than the last.

Pacing Notes

On a climb this long, discipline beats ambition. Anchor your effort to a percentage of your FTP rather than to feel, because at altitude your perceived exertion lies to you. If you do not have a recent number, run the FTP estimator before you go.

Target the flatter majority of the 40.4 km at a sustainable sub-threshold effort and treat the ramps toward 14.29% as brief over-threshold surges, not new baselines. Climbing 2045 m means hours in the saddle, so front-loading power is a mistake. Fuel and hydrate continuously — the summit at 5360 m will punish anyone running on empty.

Gearing

Gear for the steepest sections, not the average. While 5.07% forgives, the 14.29% max at over 5000 m of altitude does not — thin air robs the power you would normally lean on. A compact crankset paired with a wide-range cassette is the right foundation.

A 34×32 is the sensible minimum for most riders here, giving you a bailout ratio on the sharp ramps. If your legs are less than fresh, or you simply want to protect them across the full 40.4 km, size up to 34×34. The extra range costs nothing on the shallow sections and buys real insurance when the road tilts toward 14.29% near the top.

Summary

Changla Pass earns its HC rating through length and altitude rather than raw steepness. 40.4 km, 2045 m of net climbing, and a 5360 m summit make it one of the most demanding sustained efforts you can attempt. Pace by power, gear generously, and respect the thin air.

Length: 40.4 km
Average gradient: 5.07%
Max gradient: 14.29%
Start: 3315 m
Summit: 5360 m
Net gain: 2045 m
Total ascent: 2035 m
Category: HC