Đèo Trạm Tôn

Overview

Đèo Trạm Tôn is a Category 1 climb that trades brute steepness for sheer, relentless length. Over 28.6 km it lifts you from a valley floor at 601 m to a summit at 2005 m — a net gain of 1404 m. The average gradient of 4.91% sounds gentle on paper, but sustained across nearly thirty kilometres it becomes a test of patience and metering more than raw power. This is a climb you settle into rather than attack.

How the Gradient Unfolds

The headline number here is the gap between average and maximum: 4.91% on average, but pitching up to 12.7% at its steepest. That spread tells you the road is not uniform. Long stretches sit near or just below the average, letting you find a rhythm, punctuated by sharper ramps where the gradient more than doubles. The total ascent of 1396 m sits just below the 1404 m net gain, which means the route is almost purely uphill — there are essentially no meaningful descents or false flats giving that vertical back. Every kilometre is earning elevation. Expect to spend most of the climb in the 4–6% band, bracing for occasional bites toward that 12.7% ceiling on the tighter ramps.

Pacing Notes

On a climb this long, discipline beats ambition. Anchor your effort to a percentage of your FTP and hold it — going into the red early on a 28.6 km ascent is a mistake you pay for over the final third. A sensible target is a steady sub-threshold effort you could sustain for well over an hour, backing off slightly on the 12.7% ramps rather than surging over them. If you don't know your threshold, run the numbers through the FTP estimator before you plan the day. Because the gradient is so consistent around 4.91%, your power should stay remarkably even; big spikes are a sign you're overcooking it. Fuel and drink continuously from the start — the climb's length, not any single slope, is what breaks riders here.

Gearing

The moderate average gradient can lull you into under-gearing, but the combination of a 12.7% maximum and 28.6 km of accumulated fatigue argues for spinning-friendly ratios. A compact 34-tooth inner ring is the baseline. Paired with a 34×32, most riders will keep a comfortable cadence on the steeper ramps late in the climb. If you're carrying luggage, riding at altitude near the 2005 m summit, or simply prefer to protect your legs, step up to a 34×34 for extra margin. Either way, prioritise a gear that lets you sit and spin through the 12.7% pitches rather than grinding out of the saddle.

Summary

Đèo Trạm Tôn rewards riders who respect its length. There is no dramatic wall to conquer — just 28.6 km of honest, steady climbing at 4.91% that adds up to a serious 1404 m of vertical. Pace it evenly, gear it generously, and let the summit at 2005 m come to you.

Length: 28.6 km
Average gradient: 4.91%
Max gradient: 12.7%
Start: 601 m
Summit: 2005 m
Net gain: 1404 m
Total ascent: 1396 m
Category: 1