If it takes about 20 minutes to drive up the only road to the ski village on Ben Lomond, how long does it take to get down?   The plateau at the top of Ben Lomond National Park is some 14 kilometres long and about six kilometres wide. Indigenous peoples from the Plangermaireener nation ranged over it some 30,000 years ago and more recently the Northern Tasmanian Alpine Club began organising trips to the mountain around 1929.   Mountain bikers are one of Lomond's more contemporary additions. The unofficial record for mountain biking the 18 kilometres down the road from the top of the mountain to the bottom is also about 20 minutes.   Surprisingly, even those people who haven't been on a bike for years think it is one they can break. Give it a try – the record will seem achievable. For whether you ride or rock climb, ski or ramble, there is one certainty: this is a place to set down a personal record; what matters most is your feats on Ben Lomond will last a lifetime.