There are many cycling routes through West Dorset:

The National Cycle Network currently provides 6000 miles of cycling routes throughout the UK (www.sustrans.org.uk/default.asp?sID=1089651611859).  There are 2 routes that pass through West Dorset:

NCN Route 2 - Between Dorchester & Lyme Regis - approx 30 miles

NCN Route 26 - Between Sherbourne & Dorchester - approx 28 miles

The West Dorset Pedal - 5 cycle rides finding West Dorset's finest food & arts (http://www.westdorset.com/site/things-to-do/activities/cycling/west-dorset-pedal):

Hillforts & the Vale - Charmouth & Marshwood - main loop = 12 miles approx

Valley of the Stones - Abbotsbury & the Bride Valley - inner loop 11 miles approx plus outer loop 16 miles approx

The Frome Valley - Dorchester & Maiden Newton - 17 miles approx

Eggardon Hillfort - Loders & Powerstock - inner loop 11 miles approx plus outer loop 14 miles approx

Bridport's Market Garden - Bridport & Netherbury - main loop 15 miles approx

Purbeck's Circular routes (download routes at  www.purbeck.gov.uk/default.aspx?page=7548):

Route 1 - Priory Ride - Wareham to West Holme - 8 miles

Route 2 - Rempstone Ride - Norden to Studland & Shell Bay - 12 miles

Route 3 - Castle Ride - Wareham to Corfe Castle - 12 miles

Route 4 - Lawrence Ride - Wareham to Moreton - 22 miles

Route 5 - East Lulworth Ride - Wareham to Lulworth - 18 miles

Route 6 - Rurbeck Ride - Circular route around Purbeck - 47 miles