Severe back pain, two crashes and a chest infection forced American Andrew Talansky to become the latest top rider to abandon the Tour de France on Thursday.              

"I'm absolutely heartbroken. I built my season around the Tour, and the team has supported me every step of the way," Talansky, winner of the Criterium du Dauphine warm-up race in June, said in a Team Garmin-Sharp statement.             

"I had hoped the rest day would allow some time to recover from my crashes. I was hopeful that I could get through yesterday and I tried to be there for the team, the way they have been there for me this whole time," he added.             

"But it proved to be too much."             

Back pain forced the 25-year-old to stop by the roadside on Wednesday, the 187.5 km 11th stage from Besancon to Oyonaxx, but he got back on his bike to cross the line well behind the peloton despite initially looking poised to retire.                   

Italy's Vincenzo Nibali of Astana leads the 21-stage race by two minutes and 23 seconds from Team Sky's Richie Porte of Australia.             

Defending champion Chris Froome, two-time winner Alberto Contador and sprint specialist Mark Cavendish have already been forced out of the race due to injury after all suffered heavy crashes in a treacherous first half of the Tour.