"I think it's a chance to see the world first and foremost by bike," Cullen told Reuters TV. "You know you're literally in a country feeling all the hills, meeting all the people, so it's the best way to go and travel.
"And then the chance to raise some money as well. We're raising money for the Movember Foundation and the Ian Williams Foundation and we are looking to raise 30,000 pounds."
The Movember Foundation is a non-profit organisation that calls for men to grow moustaches during the month of November to raise awareness of men's health issues, such as prostate cancer.
Self-sufficiency will be key for the duo who have undertaken the journey with nothing more than their bikes, tents, utensils and camera equipment.
"The only things that we need to resupply along the route are food and water. So as long as we got those two things we should be good to go," Cook said.
"(We have a) GoPro as well for some footage. We've got a drone as well, it's quite cool and will get us some good shots."
Their route is expected to take them through mainland Europe after which they will pass through Turkey, Georgia, Kazakhstan and China.
"I think China's going be really interesting culturally just so different, so that's going be cool and Georgia is a country that I'm really looking forward to going to," Cullen added.
The World Cup kicks off in Japan on Sept. 20 and England's first game in Pool C is two days later against Tonga in Sapporo.
(Reporting by Rohith Nair in Bengaluru; Editing by Christian Radnedge)
