2013 Tour de France: Ones to watch

With Sir Bradley Wiggins (right) unfit to defend his 2012 Tour de France title, British hopes of winning a second yellow jersey lie with his Team Sky team-mate Chris Froome. The 28-year-old is an excellent climber and time trialist and as well as helping Wiggins to victory last year, he finished second overall.
Froome is in good shape having won four of the five stage races he has contested in the build-up to the 100th staging of the three-week race. Victories in the Tour of Oman, Criterium International, Tour de Romandie and Criterium du Dauphine have seen him installed as the man to beat in France.
Australian Richie Porte will be one of Froome's key support riders in the Alps and Pyrenees. The Team Sky rider finished second behind Froome in June's Tour warm-up race, the week-long Criterium du Dauphine but has also shown his pedigree by winning the prestigious Paris-Nice stage race in March.
Froome will also be helped by British trio Ian Stannard, Peter Kennaugh and Geraint Thomas. National road race champion Stannard, like Kennaugh is making his Tour debut. Thomas, who was, with Kennaugh, a member of the team pursuit quartet that won Olympic track gold at London 2012, is riding his fourth Tour.
Spain's Alberto Contador is likely to be Froome's main rival for the overall race win. The 30-year-old is one of only five riders to win all three Grand Tours of cycling - the Tour de France, Giro d'Italia and Vuelta a Espana. He won the Tour in 2007 and 2009 but was stripped of his 2010 victory after a positive doping test.
Andy Schleck, the 2009, 10 and 11 runner-up, profited from Contador's misdemeanour to be handed the 2010 title. The Luxembourg rider, 27, was the best young rider for three years from 2008. He missed the 2012 race through injury but is back and with a mountainous parcours, could this be his year?
Cadel Evans became the first Australian winner of the Grande Boucle in 2011 but he struggled to keep pace with Wiggins and Team Sky last year, finishing seventh. Aged 36, he will surpass his own post-war record of the oldest victor should he win the race. He is riding into form though, having finished third at May's Giro d'Italia.
Should Evans falter, BMC Racing have an able deputy in Tejay van Garderen waiting in the wings. The 24-year-old American won the best young rider category in 2012 and outperformed Evans by finishing fifth overall. He goes into this year's race as Evans's domestique but all that could change.
Spain's Alejandro Valverde broke clear of the field to win stage the mountainous stage 17 of the 2012 Tour and has Grand Tour history with victory in the 2009 Vuelta a Espana. The 33-year-old Movistar rider has been name checked by Froome as a potential rival for this year's title.
Another Spaniard, Joaquim Rodriguez, could have a decent race. The 34-year-old has only ridden the Tour once before, finishing seventh in 2010, but was second and third at the 2012 Giro and Vuelta respectively and pipped Wiggins to finish top of the UCI World Tour rankings.
The race for the green points jersey promises to be just as intriguing with Britain's sprint king Mark Cavendish aiming to regain title he won in 2011, and in doing so, become only the second rider, after Djamolidine Abdoujaparov in 1992, to win the Tour and Giro points classifications in the same year.
National road race champion Cavendish has won 23 Tour stages - the most of any active rider and fourth on the all-time list - including three in 2012 as a Team Sky rider. Germany's Andre Greipel (pictured left) also won three sprint stages last year and is again likely to provide the main opposition on the flatter stages.
Slovakia's Peter Sagan won the green jersey last year and is among the favourites to retain it. He is not as strong a sprinter as Cavendish but is likely to pick up more points on the hillier stages as he is a better climber. A flamboyant character, Sagan celebrated winning the Gent-Wevelgem one-day race by pulling a wheelie.
Then, there is the old man of the peloton. Germany's Jens Voigt is embarking on his 16th Tour de France and is an attacking rider who enjoys getting involved in breakaways. The 41-year-old, who may be riding his final Tour, is a cult hero and famed for shouting at his legs and telling them they are not tired.
Also keep an eye on the gurning face of French favourite Thomas Voeckler. He too likes to instigate breakaways and is an adept climber who won the King of the Mountains polka dot jersey in 2012. He has spent 20 days wearing the race leader's yellow jersey and will undoubtedly delight fans with more aggressive riding.
David Millar is the sixth British rider among this year's 198 starters. The Scot, who rides for Garmin Sharp, is starting his 12th Tour and has previously won four stages, including stage 12 last year. The 2007 national road race and time trial champion is the only Brit to have worn the Tour's yellow, green and polka dot jerseys.