Colletto Merlatti

Overview

Colletto Merlatti is a long, deceptively gentle-looking ascent in Italy that rewards careful reading. Over 16.6 km it climbs from a start elevation of 398 m to a summit at 977 m, a net gain of 579 m. On paper the 3.5% average gradient reads as a friendly tempo climb, and for long stretches that is exactly how it feels. But the 25.82% maximum gradient and the category 2 rating tell you the real story: this is a climb of contrasts, where the effort lives in a handful of savage pitches rather than in relentless grade.

That gap between the average and the max is the whole character of Merlatti. Ride it wrong and the steep ramps will empty your legs long before the 977 m top.

How the Gradient Unfolds

With a 3.5% average across 16.6 km, most of the road sits well below that number to make room for the extremes. Expect false flats, shallow drags, and possibly brief respites that let the total ascent of 547 m come in slightly under the 579 m net figure — a sign the profile is not perfectly monotonic and gives a little back along the way.

The defining feature is the max of 25.82%. A ramp that steep is not something you spin over; it forces you out of rhythm and into survival mode. These pitches are where the climb earns its category 2 status despite the modest overall gradient. Treat the shallow kilometres as recovery and the steep ones as the actual test.

Pacing Notes

Because the difficulty is concentrated in the ramps, pace off your FTP rather than the average grade. On the 3.5% sections, hold a controlled tempo and keep something in reserve — the 25.82% walls will demand short, sharp surges that push you well over threshold no matter how disciplined you are.

If you do not know your current threshold, estimate it first with the FTP estimator, then set a ceiling for the flatter kilometres so you arrive at the steep pitches with headroom. Over 16.6 km and 579 m of climbing, the riders who blow up are usually the ones who spent too much on the easy gradient early. Bank patience; spend it on the ramps.

Gearing

The 3.5% average is misleading for gear selection — plan for the 25.82% max. A compact 34-tooth chainring paired with a wide cassette is essential here. A 34×32 is the sensible minimum, giving you a low enough ratio to keep turning on most of the steep sections. If your legs or fitness leave any doubt, go to a 34×34, which buys crucial cadence on the very steepest ramps and keeps you from grinding to a walk near 25.82%.

Summary

Colletto Merlatti is a study in averages: a mellow 3.5% mean hiding brutal 25.82% ramps across 16.6 km and 579 m of climbing. Respect the steep sections, gear low, and pace off threshold — and the 977 m summit is very reachable.

Length: 16.6 km
Average gradient: 3.5%
Max gradient: 25.82%
Start: 398 m
Summit: 977 m
Net gain: 579 m
Total ascent: 547 m
Category: 2