the second stage came to an end, after stage winner Sylvain Chavanel took it away. However, Cancellara regained the lead the after the next day and held it until stage seven when Chavanel again took the lead. Later in the Tour, Cancellara won the stage nineteen individual time trial that stretched from Bordeaux to Pauillac by seventeen seconds over German rider Tony Martin. The Road World Championships took place in Melbourne and Cancellara returned to the event to defend his title as world champion of the time trial discipline. He won the time trial by over a minute to the second-place finisher and in doing so, he became the first four-time men's world champion of the time trial. Four days later, he competed in the road race and finished 50th overall. Allegation of 'mechanical doping' In 2010, former cyclist Davide Cassani claimed in a YouTube video that Fabian Cancellara had used a motorized bike during his victories at the Tour of Flanders and the Paris–Roubaix that year. In the video, Cassani showed a normal road bike on a stand and after he pressed a button, the pedals began to rotate. Cassani then alleged that a motor could easily be stowed in the seattube of the bike and the button to turn it on would be located on the handlebars. In the YouTube video, Cassani showed clips of Cancellara at the two races allegedly "turning on" the motor while riding and showing the drastic increase in speed. The claims caught steam since rumors were already going around about riders possibly using the new motor, the Gruber Assist, which could produce 100 Watts of power to aid the rider. Critics of the motor-theory often say that the Gruber Assist was way too noisy that time and in solo ride or a smaller group it could have surely been heard when turned on. The Union Cycliste Internationale (UCI) stated that whilst they are not investigating any specific teams or riders, it would review the need for a new bicycle inspection system to detect such cheating. Then UCI stated that there was no case against Cancellara after the claims gained prominence. Cancellara dismissed Cassani's claims saying that they were "stupid" and far too risky to do. He even told the Belgian newspaper Het Nieuwsblad that he had "never had batteries on [his] bike." During an April 2017 press conference, just before his final Ronde