LONDON - Bradley Wiggins will attempt to add cycling's world hour record to his four Olympic gold medals and 2012 Tour de France title. Wiggins intends to take a shot at what he describes as cycling's "holy grail" at London's Olympic Velodrome on June 7. Australian cyclist Rohan Dennis is the current world hour record holder, completing 52.491 kilometres on the track in Granges, Switzerland, on February 8. The 24-year-old winner of the Tour Down Under broke the previous mark of 51.852km set by Austrian Mathias Brandle. Wiggins, who finished his Team Sky career at Paris-Roubaix last Sunday, said: "The Hour Record is a holy grail for cyclists. "It's been fought over tooth and nail by some of the greatest names in our sport for over a hundred years and it's time for me to have a crack at it."