By Julien Pretot LA TOUSSUIRE, France, July 24 (Reuters) - Race leader Chris Froome hit out at defending Tour de France champion Vincenzo Nibali for launching his stage-winning attack just when the Briton suffered a mechanical problem on Friday. The incident was reminiscent of that on the 2010 Tour when Alberto Contador attacked Andy Schleck as the Luxembourg rider, then wearing the yellow jersey, had problems with his chain. "It's pretty self explanatory really, going up to the col de la Croix de Fer I had a mechanical problem," said Froome after the 19th stage. More...