A fantastic place, went there last year with the MTB and plan another trip later on. Get an OS Explorer and check out the Tennyson Trail, Shepherd's Trail, climb up Chilerton Down, and the Worsley Trail. These bits are some of a loop we did which was great fun. Lots of climbing but there is anywhere on this island, and some nice descents. Westover and Mottistone Downs are nice too, great views on the right day, windy as hell up there sometimes. That covers some of the west side of the island between Afton and Carisbrooke as the furthest east point.