Team Sky have clocked up eight Grand Tour wins since their formation, but they have also been plunged into controversy for using special exemptions to administer drugs that can enhance performance.
Al Hammadi and Daniel focused on primary school students as they visited eight schools that included visits to Ahmad Mansour School in Westbay and Lycée Voltaire in Al Waab, one day before launching their challenge.
The duo will cover a distance of more than 500kms to visit a number of schools to create road safety and active lifestyle awareness.
The pair will cover a distance of more than 500kms within the course of four days, visiting schools to raise awareness of road safety and the health benefits of physical activity.
The first and last part of the course featured elements of motocross route, appreciated by 150 riders who started the race.
Froome, 33, became the first British rider to win the Giro last May to complete a 'grand slam' after his Tour de France and Tour of Spain wins in 2017.
With a nod to Belgian legend Eddy Merckx, the 2019 Tour begins in Brussels on July 6 and ends 3,460km later on the Champs Elysees in Paris on July 28, the opening and closing stages about as flat as it gets on the 106th edition.
The Dutchman Groenewegen remains on top in the overall standings, four seconds ahead of both Ackermann and Jakobsen.
Mikkel Bjerg, recently crowned world under-23 time trial champion, was second.
Team Sky say the trophy was stolen after being momentarily left unattended while the display was packed up at the end of a cycle show
It will be the second time Australia has staged the event, after Melbourne hosted the 2010 edition when the road race was won by Norway's Thor Hushovd.
A breathless Valverde, who finished runner-up in 2003, broke down with the emotion of finally securing the rainbow jersey -- arguably the most prestigious prize in the sport.
Australia's Amanda Spratt finished second while Italy's Tatiana Guderzo was third.
Tour of Spain winner Simon Yates and his twin Adam are also among the favourites and should one of them succeed, it would be the first British winner since Mark Cavendish in 2011.
Ullrich, who won the 1997 Tour de France, is already under investigation over an incident in early August.