Andy Schleck (right) and brother Frank entertain the media on the lead-up to the 2014 Tour de France. Andy Schleck crashed on stage 3, dropped out the next day, and never raced again.

Andy Schleck (right) and brother Frank entertain the media on the lead-up to the 2014 Tour de France. Andy Schleck crashed on stage 3, dropped out the next day, and never raced again.​

One of pro cycling's most enigmatic careers has come to an abrupt end. After nine years of up and down results, crashes, fits and starts, Trek Factory Racing's Andy Schleck announced Thursday that he's retiring. The 29-year-old Luxembourger attributed the untimely end in part to a knee injury sustained in a Tour de France crash earlier this year.

"I'm obviously disappointed to end my career like this," said Schleck. "I would have liked to keep on fighting but my knee just doesn't allow it. Since my crash [at stage 3 of this year's Tour] there has hardly been any progress. While the ligaments have healed, the damaged cartilage is another story. I have been working hard on rehabbing the knee but came to the hard realization that at the risk of irreversibly injuring it, this is the best course of action."

Schleck's contract with Trek was up at the end of the year, and he'd yet to sign a new one.

During his career, Schleck rode to victory on some of cycling's biggest stages, stepping four times onto Grand Tour podiums. Among his many notable accomplishments, Schleck won the 2010 Tour de France after Alberto Contador was disqualified after-the-fact for doping. Schleck also won three Tour white jerseys as the best young rider, and triumphed at the 2009 Liège-Bastogne-Liège. Schleck highlights his win on the Galibier stage of the 2011 Tour de France as one of his most memorable achievements.

"Cycling has been my life for many years and I will need time to figure out what I'd like to do," he said. "Luckily I can count on my family, friends, and Trek who have always supported me. I am very happy to have trained and raced alongside my brother and to have made some of the best friends that I have. I have always said that cycling is not the beginning and the end of my life. I have a wonderful girlfriend and a wonderful son. I'm excited to find out what lies ahead."