Portella / Vraška škrbina

Overview

Portella / Vraška škrbina is a Category 1 climb that asks a serious, sustained effort of every rider who takes it on. Over 10.9 km it averages 7.21%, lifting you from a start elevation of 509 m to a summit at 1292 m. That is 783 m of net elevation gain, with a total ascent of 769 m once the small undulations are accounted for. There is nothing token about a climb of this length at this gradient: at just over one point below the hors catégorie threshold, it sits firmly in the "respect it or unravel" bracket. The average alone would test most riders, but the 16.02% maximum gradient means there are moments where the road rears up well beyond what the average suggests.

How the Gradient Unfolds

The headline number to internalise is the 7.21% average across the full 10.9 km. A climb that holds that figure over more than ten kilometres rarely does so evenly. The gap between the 7.21% average and the 16.02% maximum tells you the story: nearly nine percentage points of spread. That means stretches sitting comfortably under the average are paid back by ramps that push toward and beyond the maximum. With 783 m of net gain but only 769 m of total ascent, the profile is almost relentlessly upward — there are essentially no descents to recover on, just the occasional easing before the road tilts again. Treat the flatter sections as the climb's only gift, not as rest.

Pacing Notes

The single most important discipline here is holding your effort steady relative to your FTP. At 10.9 km, this is a 30-to-50-minute effort for most riders, which puts it right around threshold territory — meaning small overspends compound painfully. Anchor your pacing to a power or heart-rate ceiling before the first steep ramp arrives, then defend it. When the gradient spikes toward 16.02%, let your speed drop rather than your control; chasing a number on the steepest pitches is how riders blow apart with kilometres still to climb. If you do not know your threshold, run the numbers through the FTP estimator first so your target on the day is honest rather than hopeful.

Gearing

Gearing is not optional insurance on Portella / Vraška škrbina — it is the difference between a rhythm and a grovel. With a 7.21% average and pitches to 16.02%, most riders will want a compact chainring paired with a wide-range cassette. A 34×32 is a sensible baseline and will carry strong climbers through the steeper ramps at a survivable cadence. If you are carrying fatigue, riding at altitude near the 1292 m summit, or simply prefer to spin, step up to a 34×34 for extra headroom on the 16.02% sections. Over 10.9 km of climbing, protecting your cadence protects your legs.

Summary

Portella / Vraška škrbina is a long, honest Category 1 climb: over 10.9 km at 7.21%, with real teeth in its 16.02% maximum. Pace to threshold, gear generously, and let the numbers — not your ego — set the tempo.

Length: 10.9 km
Average gradient: 7.21%
Max gradient: 16.02%
Start: 509 m
Summit: 1292 m
Net gain: 783 m
Total ascent: 769 m
Category: 1