Mancebo is a stage race specialist, with good climbing and individual time trial performances.

Mancebo was himself implicated in the Operación Puerto doping case and was pulled from that year's Tour de France on the eve of the race.

Contrary to reports circulating at the time, Mancebo denies that he ever retired after news of the affair broke.

For 2010 he rode with Heraklion Kastro-Murcia and with the Canyon Bicycle's Team in the Tour of Utah, in an effort to defend his overall classification title.

For 2012 he rode with the Competitive Cyclist Racing Team repeating as the NRC Champion and named Stage Racer of the Year by VeloNews.