Doi Suthep

Overview

Doi Suthep is a Category 1 climb that packs a serious challenge into a compact 10.9 km. From a start at 353 m, the road grinds upward to a summit of 1034 m, delivering 681 m of net elevation gain over a route that never really lets you settle. The average gradient of 6.26% would be respectable on its own, but the presence of pitches as steep as 10.72% means the true difficulty sits above what that number suggests. This is a climb where consistency of effort matters more than raw power, and where a smart pacing plan pays dividends long before you reach the top.

How the Gradient Unfolds

The defining feature of Doi Suthep is the gap between its average and its maximum. At 6.26% mean gradient, you have a climb that stays honest for most of its length, but the 10.72% peak tells you there are ramps that spike well into double digits. With 688 m of total ascent against 681 m of net gain, there are effectively no meaningful descents to recover on — almost every metre you climb is metre you keep. That makes Doi Suthep a steady, cumulative effort rather than a series of distinct walls with rest in between. Expect the steeper sections to arrive as sharp kicks that force you out of rhythm, followed by stretches nearer the average where you can claw back your cadence before the next pitch.

Pacing Notes

Because the climb is long and unbroken, your best tool is discipline. Ride the opening kilometres a little below your threshold to leave headroom for the 10.72% ramps, which will spike your power whether you want them to or not. Aim to hold a steady effort anchored to your FTP rather than chasing the gradient — surging into every steep section on a 6.26% average climb is the fastest way to blow up before the summit. If you are unsure of your current threshold, run the numbers through the FTP estimator first so your target wattage is realistic. Over 10.9 km, a controlled 90% of FTP that you can sustain will beat a punchy start that collapses in the final third.

Gearing

For a climb averaging 6.26% with ramps to 10.72%, gearing is your friend. A compact 34-tooth inner chainring paired with a 34×32 cassette gives most riders enough range to spin the steeper pitches without grinding to a stall. If you carry extra weight, ride at altitude, or simply prefer to protect your knees over a sustained 681 m of gain, step up to a 34×34 for that extra margin on the double-digit sections. The lower gear costs you nothing on the mellower stretches and keeps your cadence alive when the road tilts hardest — exactly where cadence is easiest to lose.

Summary

Doi Suthep is a proper Category 1 test: short enough to attack, steep enough to punish, and long enough to reward a patient, well-paced effort. Respect the ramps, gear low, and hold your rhythm to the 1034 m summit.

Length: 10.9 km
Average gradient: 6.26%
Max gradient: 10.72%
Start: 353 m
Summit: 1034 m
Net gain: 681 m
Total ascent: 688 m
Category: 1