Alto de Trevim

Overview

Alto de Trevim is a category-1 climb that trades brutal steepness for sheer, unrelenting length. Over 23.3 km it lifts you from a valley floor at 72 m to a summit of 1195 m, a net gain of 1123 m. Factor in the rolling dips and recoveries along the way and the total ascent swells to 1132 m — proof that the road does not simply point uphill and stay there. The headline average of 4.82% sounds gentle, but averages lie on a climb this long. At more than 23 km, it is the kind of effort that rewards patience and punishes ego.

How the Gradient Unfolds

The 4.82% average is best read as a warning rather than a promise. Spread across 23.3 km, that figure hides both the easy false flats and the sting in the tail: gradients touch a maximum of 16.5%, more than three times the mean. Expect the climb to breathe — shallow stretches where you can settle into a rhythm, punctuated by sharper ramps that force you out of the saddle. Because the total ascent (1132 m) exceeds the net gain (1123 m), there are short descents or level sections built in, meaning you lose and re-earn a little height along the way. Those give your legs a flicker of relief, but they also break your cadence, so treat each recovery as a chance to eat, drink and reset before the next pitch.

Pacing Notes

On a climb of this duration, discipline beats bravado. Your FTP is the number that matters here: hold a steady sub-threshold effort and let the 16.5% ramps momentarily push you above it, rather than burning matches on the shallow early kilometres. A good target is to ride the bulk of the 23.3 km just under threshold, keeping enough in reserve that the steepest ramps don't blow you apart. If you're unsure of your current number, run through the FTP estimator before you commit to a pace. The climb is long enough that a 10-watt pacing error compounds badly over an hour or more of effort — start conservative and finish strong.

Gearing

With 1123 m of climbing packed into ramps as steep as 16.5%, gearing is where you save your race. A compact 34-tooth chainring paired with a wide cassette is the sensible baseline. A 34×32 will get most fit riders over the top, but on a climb this long, fatigue turns moderate gradients into hard ones — so if your legs or your loaded bike suggest any doubt, size up to a 34×34 for that extra margin on the steepest pitches. The goal is to protect your cadence: spinning a slightly easier gear across 23.3 km costs far less than grinding and cramping in the final kilometres.

Summary

Alto de Trevim is a test of endurance and pacing rather than raw explosive power. Respect the distance, gear low, and ride within yourself, and the 1195 m summit is well within reach.

Length: 23.3 km
Average gradient: 4.82%
Max gradient: 16.5%
Start: 72 m
Summit: 1195 m
Net gain: 1123 m
Total ascent: 1132 m
Category: 1