The most important aim of the Downslink Challenge is to raise money for Chestnut Tree House but not far behind comes the absolute rule - have fun. The event started as a social occasion and aims to remain that way.
Perhaps you are a serious cyclist participating in races and events most weeks. Why not bring the family along to this one. Although mainly off road the track is still suitable for most riders. Do part of the ride with them then ride on for the full distance and meet up on the way back.