But negotiating the rough Egypt terrain in searing 45 degree heat is proving a challenge. "The heat is something else, you can't really prepare for it," says Ewan - who on this journey has decided to forgo a beard like the one he grew on his last trip. "This is the hottest place I've ever been to in my life!" added Charlie on their log. But their spirits were lifted by the sight of Cairo's magnificent pyramids. "It was beautiful being there, it was really moving being by the pyramids, it was lovely, just lovely," he said in a call to radio DJ Chris Moyles.
Their bikes have certainly taken a pounding, especially in the sand. "I come off all the time," admits Ewan, whose French wife Eve is due to join him for a fortnight when they hit Malawi after taking motorcycling lessons. "I'm off more than anybody else, when it comes to falling off I am the team faller." That's not the only problem they're facing as this journey is considered more hazardous than their last. The friends have completed hostile environment training, including scenario-based exercises like conduct after capture as well as medical training, the same as BBC foreign correspondents before they go on risky assignments.
The adventure, which ends at the southernmost point of Africa, is in aid of charity. And two lucky fans will be able to join the 36-year-old Star Wars actor and his thespian friend for the last leg after they decided to auction off the opportunity in aid of the Riders For Health charity - which helps African health workers get to patients in remote areas.
For those who aren't in the midst of a 15,000 mile trip and have more time to explore Egypt's wonders, then the legendary Valley of the Kings is a must. Standing on the west bank of the Nile across from Luxor, it boasts tombs and temples from the 18th and 19th Dynasties and is famous for the discovery of the tomb of Tutankhamun. A sailing trip along the river Nile in a felucca, or traditional Egyptian sailing boat, is also well worth while - stopping at Aswan where Agatha Christie wrote Death On The Nile at the Old Cataract Hotel. Aswan's treasures include The Philae Temple devoted to the goddess Isis and the Aga Khan's Mausoleum and Botanical gardens.