East of Corfe, the chalk headlands of the Isle of Purbeck have several ridgelines with awesome singletrack trails.
The Purbeck Hills mountain bike ride is a 9 mile out and back on the southern flank of a rolling barren ridge. To reach the mountain biking trailhead from Wareham, follow A351 to Corfe. Use the car park below Corfe Castle. Best ridden in dry weather.
Theres also a 23 mile route staring from the same place. It runs a ridgeline down to Chapmans Pool, then follows a steep climb out and back to St Aldhelms Head. Next, follow Priests Way to Swanage and on up to Ballard Down. Head over to Old Harry and drop into Studland. Climb back up Nine Barrow Down and run the ridge to a nice descent to Corfe Castle.
Overall, Purbeck Hills is the 22nd most popular mountain bike trail of all 93 mountain biking rides in UK.