In this month's Adventure Show, Dougie Vipond joins the hardiest of bikers for one of the toughest events in the cycling calendar. The Snow Roads Audax is aptly named: it's a 300-kilometre bike ride with nearly 5,000 metres of ascent over some of Scotland's steepest hills - those high passes, like the Lecht and Glenshee, which are often snowbound in winter.