All eyes will be on the known quantities for the Giro'd'Italia. Alberto Contador will be hoping to write himself into the history books as Richie Porte, Fabio Aru and Rigoberto Uran battle to break through at Grand tour level, but can a rank outsider upset the favourites?

9 May 2015 - 9:42 AM  UPDATED 9 May 2015 - 9:44 AM

Alberto Contador (ESP) Tinkoff-Saxo
Major results: Tour de France winner (2007, 2009), Giro d'Italia winner (2008), Vuelta a Espana winner (2008, 2012, 2014), Paris-Nice winner (2007, 2010), Tirreno-Adriatico winner (2014), Tour of the Basque Country winner (2008, 2009, 2014).

The Spaniard has the experience and ability to romp to a seventh Grand Tour victory but two elements may work against him. Contador is also targeting July's Tour de France, which is arguably a greater aim, and he is no longer the force he once was, prior to his doping suspension. Even so, he proved in winning last year's Vuelta that he is still one of the best climbers in the world and if he can avoid losing too much time to the time trial specialists in the 60km stage 14 race against the clock, it is hard to look beyond the 32-year-old.

Richie Porte (AUS) Team Sky
Major results: Giro d'Italia 7th (2010), Tour de France 19th (2013), Paris-Nice winner (2013, 2015), Volta a Catalunya winner (2015), Giro del Trentino winner (2015), Volta ao Algarve winner (2012), Criterium du Dauphine 2nd (2013), Tour of the Basque Country 2nd (2013).

The Tasmanian has never really kicked on since an impressive seventh-placed finish on his Giro debut in 2011. He has more often than not disappointed in Grand Tours. Yet his form in one-week stage races is impressive, particularly this season. He won Paris-Nice for the second time and also triumphed at the Volta a Catalunya. Back in 2013 he was second in the Criterium du Dauphine despite riding as a domestique for team leader Chris Froome, who won. But it remains to be seen if the 30-year-old can transfer that to the three-week format.

Fabio Aru (ITA) Astana
Major results: Giro d'Italia 3rd, plus one stage win (2014), Vuelta a Espana 5th, plus two stage wins (2014), Giro della Valle d'Aosta winner (2011, 2012).

The Sardinian is only 24 but he had a breakout season in 2014 where he finished third at the Giro and fifth at the Vuelta, taking three stage wins along the way. Seen as the natural successor to compatriot and Astana teammate Vincenzo Nibali, the Tour de France champion, much is expected of Aru. But his preparations have been upset by a stomach virus in April and he has only 15 race days in his legs this year.

Rigoberto Uran (COL) Etixx-QuickStep
Major results: Giro d'Italia 2nd (2013, 2014), Olympic Games road race 2nd (2012), Tirreno-Adriatico 3rd (2015), Volta a Catalunya 2nd (2008), Tour de Romandie 5th (2009, 2015).

Having finished second the last two years, Uran should be there or there abouts and a top five finish, or even podium finish is a near-certainty. But there are question marks over his ability to actually take the next step and win a major race. Too often the 28-year-old comes close, like the 2012 London Olympics, but without ever claiming the cigar. High finishes are his speciality, winning is not.

Ilnur Zakarin (RUS) Katusha
Major results: Tour de Romandie winner (2015), Tour of Azerbaijan winner (2014), Russian timetrial champion (2013), Junior European timetrial champion (2007), GP Sochi winner (2014), GP Adygeya (2012, 2014).

A week ago 25-year-old Zakarin was an almost unknown but his stunning victory at the Tour de Romandie, beating the likes of Chris Froome, Vincenzo Nibali and Nairo Quintana, has catapulted him into the pre-Giro limelight. His three-week Tour capabilities are totally unknown but his Romandie win suggests he should be considered a contender. However, having already served a two-year doping suspension earlier in his career, his sudden rise has obviously raised eyebrows and he will be under as much scrutiny for his results as for his biological passport readings in Italy.

Giro d'Italia broadcast details
SBS will broadcast every stage of the Giro d'Italia live. When possible, we will also live stream the race online here at Cycling Central before the television broadcast begins. In addition to morning highlights online, there will be highlights every day at 6pm on SBS 2.