Dieng

Overview

Dieng is a short but genuinely demanding category 2 climb. In just 4 km it lifts you 300 m from a start at 1790 m to a summit at 2090 m, holding a 7.43% average the whole way. That average is deceptive, though: with a maximum pitch of 22.91%, this is a climb defined by its steepest moments rather than its length. Because the summit sits above 2000 m, the thinner air at altitude adds a subtle tax on top of the raw gradient — your legs and lungs both pay.

How the Gradient Unfolds

The headline numbers tell most of the story. Over 4 km the road gains 300 m net, but the total ascent is 357 m — the extra 57 m signals that the profile isn't perfectly smooth. Somewhere along the way the road eases or dips before clawing back upward, which means the climbing sections are steeper than the 7.43% average suggests. The 22.91% max gradient is more than three times the average, so expect at least one wall that forces you fully out of the saddle. The pattern here is punchy: stretches near or above the average, punctuated by short, brutal ramps. Ride the average and the steepest pitch will still catch you out.

Pacing Notes

On a climb this short, the temptation is to attack from the base — resist it. Four kilometres is long enough to blow up spectacularly if you overcook the first ramp. Aim to sit just under your threshold on the sustained sections and save a match for the 22.91% pitch, where cadence collapses and power spikes whether you like it or not. A good rule of thumb: hold the average grade at a controlled effort around your FTP, then accept that the steepest ramp will push you well over it briefly. If you don't know your threshold, the FTP estimator will give you a working number to pace against. With only 300 m to gain, the whole effort is measured in minutes, not hours — so the cost of a bad pacing decision is a ruined climb, not a ruined day.

Gearing

Do not under-gear this one. A 22.91% ramp at altitude will shred any setup that tops out too tall. On a compact 34-tooth chainring, a 34×32 is the sensible minimum, giving you a near 1:1 ratio for the sustained 7.43% grind. But given the max pitch, most riders will be far happier with a 34×34, which drops the ratio just below 1:1 and lets you spin rather than lurch through the steepest metres. If your cassette allows more range, take it — there is no prize for grinding this climb in too big a gear.

Summary

Dieng packs a full category 2 punch into 4 km: a steady 7.43% average hiding a savage 22.91% wall, all delivered at altitude above 2000 m. Gear low, pace with discipline, and respect the steepest ramp.

Length: 4 km
Average gradient: 7.43%
Max gradient: 22.91%
Start: 1790 m
Summit: 2090 m
Net gain: 300 m
Total ascent: 357 m
Category: 2