Bocca di Fobia

Overview

Bocca di Fobia is a hors catégorie ascent, the hardest rung on the climbing ladder, and its numbers make the case immediately. Over 16.7 km the road climbs at an average gradient of 7.35%, lifting you from a start elevation of 62 m to a summit at 1289 m. That is a net elevation gain of 1227 m, though the total ascent of 1305 m tells you the road is not a single clean ramp — there is enough undulation packed in to add another 78 m of climbing on top of the net figure. This is a long, high-consequence effort where pacing decides everything.

How the Gradient Unfolds

An average of 7.35% across 16.7 km is punishing on its own, but the max gradient of 33.37% is where Bocca di Fobia earns its HC label. A wall that steep is more than four times the average, so the climb is not evenly spread — there are stretches far gentler than 7.35% that let you breathe, balanced against pitches severe enough to force you out of the saddle or off the bike entirely. The gap between the total ascent of 1305 m and the net gain of 1227 m confirms the profile rolls rather than climbs in one continuous line. Read the road ahead: bank effort on the shallower sections and brace for the ramps.

Pacing Notes

On a climb this long, discipline beats bravado. Your FTP is the anchor number here — riding sustainably below threshold on the 7.35% average leaves headroom for the near-vertical 33.37% pitches, where power spikes are unavoidable. Blow up early and 16.7 km becomes an eternity. If you are unsure of your threshold, run the numbers through the FTP estimator before you commit, then set a target that keeps you steady from the 62 m base all the way to 1289 m. Save something for the second half — the total ascent of 1305 m means the work keeps coming long after you expect the road to relent.

Gearing

Gear for the wall, not the average. A 33.37% max gradient will overwhelm anything built for rolling terrain, so favour the widest range your setup allows. A compact chainring paired with a 34×32 low is the sensible starting point for strong climbers, but on a 16.7 km HC effort most riders will be grateful for a 34×34, which shaves the strain on both the steep ramps and the tired legs of the closing kilometres. If your frame accepts an even larger cassette, take it — spinning a low gear across 1227 m of net gain protects your knees and keeps cadence alive where mashing a big gear would end your ride early.

Summary

Bocca di Fobia is a genuine hors catégorie test: long at 16.7 km, steep on average at 7.35%, and brutal at its 33.37% max. Pace it against your threshold, gear low, and respect the total ascent of 1305 m.

Length: 16.7 km
Average gradient: 7.35%
Max gradient: 33.37%
Start: 62 m
Summit: 1289 m
Net gain: 1227 m
Total ascent: 1305 m
Category: HC