43 hours roughly, was back in 2005. Went out riding for a whole day with my mate, after that we set off into the mountains to ride natural (big 4 day ride), traveled at night. Once we got there we rode till the evening, got something to eat and went to a few parties. Got into bed around 5am What kept us going was a 1L mixture of redbull, guarana and VERY strong tea (5 teabags or so). We didn't even finish the drink