An extension of Puerto de Navacerrada, Bola del Mundo has become one of the most feared summit finishes in the Vuelta a España, with a final concrete access road climbing to 23% above Madrid.
A brutally hard finish
From Navacerrada, it’s 12.3 km for 1,058 m of elevation gain, averaging 8.6%. The final 3 km, on the military access road beyond Puerto de Navacerrada, exceed 12% average with peaks of 23%.
An unusual surface near the top
Unlike the standard asphalt of Puerto de Navacerrada, the last kilometres run over a rough concrete military service road, an unusual surface that adds a further layer of difficulty to the already extreme gradient.
Getting the ride right
An extra-wide gear range is essential for any hope of clearing the 23% pitches near the top without putting a foot down, and pacing needs to leave a real margin for the final three kilometres.
When to go
May to October — the summit’s altitude, above 2,250 m, often leaves the road snow-covered or unrideable outside this window.
Good to know
Puerto de Navacerrada, an intermediate point on the climb, offers a useful spot to refuel before the final section, while Madrid remains just over an hour’s drive away.
