Đèo Prenn

Overview

Đèo Prenn is a 7 km climb that rewards rhythm over brute force. From a start elevation of 1087 m it lifts you to a 1400 m summit, a net gain of 313 m at an average gradient of 4.46%. That average places it firmly in the tempo bracket — steep enough to demand attention, shallow enough that a well-judged effort carries you all the way up without ever tipping into survival mode. Its category 3 rating tells the story: this is a climb you ride through, not one that stops you cold. The total ascent registers at 301 m, a touch under the net figure, which hints at a road that mostly points upward with only the smallest reprieves.

How the Gradient Unfolds

The defining trait of Đèo Prenn is consistency. With an average of 4.46% and a maximum of 7.98%, the gap between typical and hardest is modest — roughly 3.5 percentage points. There are no wall-like ramps here, no double-digit pitches waiting to ambush tired legs. Instead you get a steady incline that firms up toward its 7.98% peak and eases back to the mid-fours elsewhere. Because total ascent (301 m) sits just below net gain (313 m), you can infer the road climbs almost continuously, with negligible descending in between. Read the gradient as one long, honest drag rather than a series of surges — pace it like a sustained effort and the summit arrives smoothly.

Pacing Notes

A climb this even is a pure test of sustainable output. Target an effort right around your FTP for the 7 km — the near-uniform 4.46% grade means power translates directly into forward speed, with no sharp ramps to force you over threshold. If you do not know your threshold number, run the FTP estimator before you ride so you can anchor your pacing to real data. Hold something a shade below FTP through the opening kilometres, then let the effort build as the gradient firms toward its 7.98% maximum in the steeper section. The margin between the 4.46% average and that 7.98% peak is small enough that you should barely need to shift your rhythm — settle in early and stay there.

Gearing

For a 7 km climb at 4.46% with a 7.98% ceiling, standard compact gearing is comfortably up to the task. A 34×32 bottom gear gives most riders enough range to spin the steeper pitches without grinding, keeping cadence high across the sustained middle. If you prefer to sit and spin, or you are carrying fatigue into the climb, a 34×34 buys extra insurance for the 7.98% section and lets you protect your legs over the full 313 m of gain. Neither is overkill on a category 3 ascent — pick 34×32 for a punchier rhythm, 34×34 for pure comfort.

Summary

Đèo Prenn is a steady, honest 7 km climb: 313 m of net gain, a 4.46% average, and a manageable 7.98% maximum. Pace it near threshold, gear for comfort, and enjoy a category 3 that rewards a smooth, sustained effort all the way to 1400 m.

Length: 7 km
Average gradient: 4.46%
Max gradient: 7.98%
Start: 1087 m
Summit: 1400 m
Net gain: 313 m
Total ascent: 301 m
Category: 3