The 29-year-old from Melbourne revealed that it was his determination to turn his very good cycling career into something great that was behind his decision to leave Australian cycling team Orica-GreenEDGE.
Australia's first team in the Tour de France has had a notable turnover in riders, with Clarke among the biggest departures.
Clarke had been with GreenEDGE since their inception in 2012, but he has signed a two-year deal with the Cannondale-Garmin team.
Clarke said he had to make a fresh start as he enters the prime of his professional career.
"It was a very hard decision to make, to leave what is a good team," he said.
"When I first went to GreenEDGE, I thought I'd signed up for life.
"But when you're trying to be the best you can be and the best in the world, you need to make tough decisions for the best interests of your own career."
Clarke has gone to Cannondale-Garmin to pursue his goal of winning one of the prestigious Ardennes Classics: the Fleche-Wallonne, Amstel Gold and Liege-Bastogne-Liege.
Clarke is the only Orica-GreenEDGE rider to win a category in a Grand Tour, taking out the king of the mountain at the 2012 Vuelta a Espana.
He has also achieved the rare distinction of winning a stage in all three of cycling's Grand Tours. He won a stage of the Vuelta a Espana in 2012, the Tour de France in 2013 and the Giro d'Italia in 2015.
But claiming a one-day Ardennes Classics race would take his career to a new level.
"I've proved myself with my stage wins at a Grand Tour level that I'm a good rider," he said.
"I want to take that next step."
He notes that Orica-GreenEDGE star Simon Gerrans, an all-time Australian cycling superstar, also has stage wins in the three Grand Tours.
"Winning stages of Grand Tours doesn't make you a champion," he said of Gerrans.
"But winning Milan-Sanremo and Liege does."
Clarke agreed he and his friend Richie Porte are taking the same step.
Porte is leaving the security of the powerful Team Sky squad to pursue his own Grand Tour ambitions at BMC.
Just as Porte had done well supporting two-time Tour de France winner Chris Froome at Sky, Clarke had done stellar work alongside Simon Gerrans and Michael Matthews at GreenEDGE.
"When you have quality rides like he (Porte) had, it makes you think - okay, if I was the actual captain, what would I be able to achieve?" he said.
"Our careers are so short that you'd be silly not to ask yourself that question."