Book excerpt: The Great British Mountain Bike Trail Guide reveals the best trails to ride across the British Isles. Road-tested by experienced rider Clive Forth, this is a must-have resource for any mountain biker. • A comprehensive guide – covering the best purpose-built trail centres • Trail evaluation helps you decide which trail to ride: the grading, the facilities, the ride experience • Handy size, packed with clear maps, helpful photos and trail description • Trails from across Britain and Ireland featured.