There was an unpleasant sense of déjà-vu at the start of stage 16. Frank Schleck's positive drug test continued a dishonourable Tour de France tradition of rest day drug busts. Schleck himself denies taking any banned substance and withdrew from the race awaiting the result of his 'B' sample. But it was a reminder of cycling's darker days ahead of this year's showpiece. A punishing 197 km stage combining four substantial climbs, including the Col du Tourmalet, one of professional cycling's great arenas. If there was ever a stage to truly test Bradley Wiggins this was it.